Crystal Revision
These are COPPER SULPHATE CRYSTALS (CuSO4)
Method:
Part 1:
1. Weigh 7g of copper sulphate powder into a 250ml beaker using an electric balance
2. Collect 100ml of copper sulphate into a second beaker
3. Add 7g of copper sulphate to the solution and stir (to make solution saturated)
4. Heat beaker and stir to dissolve the solid powder (solution now supersaturated)
5. Pour the warm solution into the clean petri dish until 2/3 full and leave overnight (time is required in order for the solution to cool and solidify into crystals. The solution is now less but still supersaturated)
6. Cover the rest of a solution with a cardboard lid
Part 2:
7. Choose 2 seed crystals and place them on clean paper. (Shape/figure is more important than size as it is the template for the final crystal) Measure and draw one crystal. DO NOT TOUCH THE CRYSTAL (copper sulphate is poisonous and thus potentially harmful)
8. Tie a slip knot around the other seed crystal with cotton thread
9. Suspend the thread through the cardboard lid
10. Tip the remaining crystals back into the solution. You may need to scrape the crystals with a spatula (Crystals may have solidified onto the bottom of the dish)
11. Heat the solution until ALL of the solid has dissolved (This is increasing the saturation of the solution again)
12. COOL the solution in a shallow, cold water bath (otherwise the suspended seed crystal will melt)
13. Hang the crystal in the cool solution and leave to grow
Explanation:
As the supersaturated solution cools, the excess copper sulphate will solidify onto the seed crystal. Shape is maintained though the size will increase. Particles basically join evenly to the template as opposed to falling to the bottom of the beaker.
-Crystals grow by adding single layers of molecules at a time
-As the water cools and evaporates, the solid is forced out make these layers
-Crystal shape depends on the arrangement of atoms
Definitions:
Solution: Mixture of substance dissolved into another, solvent + solute = solution
Solvent: Does the dissolving (usually liquid, H2O)
Solute: Is dissolved (CuSO4 powder)
Unsaturated solution: Where the solution can hold more than what is dissolved into it
Saturated solution: Where the solution is holding exactly what it can. Adding excess will result in solid falling to the bottom, but solution itself remains saturated.
Supersaturated solution: Where excess solute is dissolved into the solution. It requires heat. When cooled, particles will be forced out of liquid and re-solidify.
Monday, August 16, 2010
Sunday, August 15, 2010
Geog Revision
Plate Tectonics Revision
Wegener’s continental drift theory stages:
200 million years ago - Supercontinent Pangaea, Australia touching Antarctica and Indian Asia
180 million years ago - Split into Laurasia up north and Gondwanaland south
135 million years ago - Continents began to break up, Australia attached to Antarctica
65 million years ago - Further breaking up, Australia moved north-east into isolation
Today - Current positions
50 million years later – Australia to move further north
Types of plates:
Continental Plates:
Carry land masses, continents, above
Some also hold oceans, but they are named after the land. Eg. North American Plate
Made of lighter, less dense rock. Eg. Quartz and feldspar
Normally do not subduct
Oceanic Plates:
Carry oceans above
May carry small land masses, islands, but named after the ocean. Eg. Pacific Plate
Made of heavier, denser rock. Eg. Mainly basalt, (granite?)
Tend to subduct in a collision
Important information:
-Rocks deep underground can be studied through rocks from volcanoes and by looking at seismographs or seismic waves (shifting rocks create energy)
-Deep underground, the high pressure keeps rocks solid by compacting and compacting particles (liquid takes up more space than solid)
-Middle of earth probably made of iron, as rock alone would not be able to make up the weight (measured using Cavendish balance) and magnetism of the earth which make compasses work is based on this iron core. The field of magnetism from N to S poles protect the earth from solar winds
-The middle of the earth is liquid outside and solid inner section
-Like gases, hot molten rock will rise (to form volcanoes) and cool rock will sink
-Volcanoes are created when molten rock rises through up through the crust
-When a plume of hot rock pushes through the mantle, cooler rock is forced aside causing volcanic ridges. The old crust moves aside and magma fills the gap to develop new crust
-Positions on the edge of a plate are more tectonically active. Australia is in centre so it is not
-A normal fault is where rocks are pulled apart and one side drops down
-Large faults can cause earthquakes
-Folding and breaking of rocks plus grinding of one plate under another can cause earthquakes to occur
-When rocks break and slip, earthquakes can occur
-Trench is a long narrow valley on the ocean floor
-Subduction is the action of a plate (usually oceanic) sliding beneath another plate upon collision
-When an oceanic plate subducts and causes an earthquake, a tsunami can also occur
-Subduction zone is the area where a plate subducts
-Plates are constantly on the move, they move at a rate of 5 to 15cm per year
Convection Currents:
This is the heat-driven motion that causes plates to move and rocks to travel in a circular motion within the earth. They are within the mantle
Currents moving away from each other = diverging = crust pulled apart
Currents moving toward each other = converging = crush pushed together
Plate Boundaries:
1. Divergent/Constructive Boundary
-Movement of plates away from each other
-Plates can be oceanic or continental
-Gap caused called a rift or ridge
-Magma fills rift, volcano formed
-New crust created
-e.g. Mt Kilimanjaro, East African Rift, Mid-Atlantic Rift, Iceland
2. Convergent/Collision/Destructive Boundary
-Plates move toward each other
-Ocean to continent = oceanic crust subducts and melts, land on continental crust folds upward, volcano and rift forms. E.g. Mt St Helens, USA
-Ocean to ocean = one piece of crust subducts and melts, volcano (underwater) and trench forms. E.g. Japan, Indonesia, Caribbean Islands, Philippines (island arcs)
-Continent to continent = none or very little subduction occurs; continents on top of the plates collide and fold upwards to form mountains. E.g. Himalayas (Indian and Eurasian Plates), Andes (fold mountains?)
3. Transform/Conservative Boundary
-Plates slide alongside each other
-Can be oceanic or continental
-May move in the same or opposite direction
-Causes a fault e.g. Sand Andrea Fault, California (Pacific and North American Plates)
Helpful sites:
http://geology.com/nsta/convergent-plate-boundaries.shtml
http://www.waterencyclopedia.com/Oc-Po/Plate-Tectonics.html
Wegener’s continental drift theory stages:
200 million years ago - Supercontinent Pangaea, Australia touching Antarctica and Indian Asia
180 million years ago - Split into Laurasia up north and Gondwanaland south
135 million years ago - Continents began to break up, Australia attached to Antarctica
65 million years ago - Further breaking up, Australia moved north-east into isolation
Today - Current positions
50 million years later – Australia to move further north
Types of plates:
Continental Plates:
Carry land masses, continents, above
Some also hold oceans, but they are named after the land. Eg. North American Plate
Made of lighter, less dense rock. Eg. Quartz and feldspar
Normally do not subduct
Oceanic Plates:
Carry oceans above
May carry small land masses, islands, but named after the ocean. Eg. Pacific Plate
Made of heavier, denser rock. Eg. Mainly basalt, (granite?)
Tend to subduct in a collision
Important information:
-Rocks deep underground can be studied through rocks from volcanoes and by looking at seismographs or seismic waves (shifting rocks create energy)
-Deep underground, the high pressure keeps rocks solid by compacting and compacting particles (liquid takes up more space than solid)
-Middle of earth probably made of iron, as rock alone would not be able to make up the weight (measured using Cavendish balance) and magnetism of the earth which make compasses work is based on this iron core. The field of magnetism from N to S poles protect the earth from solar winds
-The middle of the earth is liquid outside and solid inner section
-Like gases, hot molten rock will rise (to form volcanoes) and cool rock will sink
-Volcanoes are created when molten rock rises through up through the crust
-When a plume of hot rock pushes through the mantle, cooler rock is forced aside causing volcanic ridges. The old crust moves aside and magma fills the gap to develop new crust
-Positions on the edge of a plate are more tectonically active. Australia is in centre so it is not
-A normal fault is where rocks are pulled apart and one side drops down
-Large faults can cause earthquakes
-Folding and breaking of rocks plus grinding of one plate under another can cause earthquakes to occur
-When rocks break and slip, earthquakes can occur
-Trench is a long narrow valley on the ocean floor
-Subduction is the action of a plate (usually oceanic) sliding beneath another plate upon collision
-When an oceanic plate subducts and causes an earthquake, a tsunami can also occur
-Subduction zone is the area where a plate subducts
-Plates are constantly on the move, they move at a rate of 5 to 15cm per year
Convection Currents:
This is the heat-driven motion that causes plates to move and rocks to travel in a circular motion within the earth. They are within the mantle
Currents moving away from each other = diverging = crust pulled apart
Currents moving toward each other = converging = crush pushed together
Plate Boundaries:
1. Divergent/Constructive Boundary
-Movement of plates away from each other
-Plates can be oceanic or continental
-Gap caused called a rift or ridge
-Magma fills rift, volcano formed
-New crust created
-e.g. Mt Kilimanjaro, East African Rift, Mid-Atlantic Rift, Iceland
2. Convergent/Collision/Destructive Boundary
-Plates move toward each other
-Ocean to continent = oceanic crust subducts and melts, land on continental crust folds upward, volcano and rift forms. E.g. Mt St Helens, USA
-Ocean to ocean = one piece of crust subducts and melts, volcano (underwater) and trench forms. E.g. Japan, Indonesia, Caribbean Islands, Philippines (island arcs)
-Continent to continent = none or very little subduction occurs; continents on top of the plates collide and fold upwards to form mountains. E.g. Himalayas (Indian and Eurasian Plates), Andes (fold mountains?)
3. Transform/Conservative Boundary
-Plates slide alongside each other
-Can be oceanic or continental
-May move in the same or opposite direction
-Causes a fault e.g. Sand Andrea Fault, California (Pacific and North American Plates)
Helpful sites:
http://geology.com/nsta/convergent-plate-boundaries.shtml
http://www.waterencyclopedia.com/Oc-Po/Plate-Tectonics.html
Friday, August 6, 2010
Maths Tests
Hello everybody!
Unless you were sick, away, at strings, or extremely lucky, you have probably had a maths test today. It was on linear graphs; a topic which appeared to be of a quarter science, a quarter finance, a quarter maths and the rest was dot-to-dot. I’m not sure about you, but I didn’t go too well. At any rate, it has inspired this post on:
MATHS TESTS
Okay, firstly here’s a joke:
Q: How many legs does an octopus have?
A: Eight
This one was courtesy of year 5 maths. It does make you wonder, who makes these maths worksheets?
But back to the point, maths tests can be exceedingly stressful experiences, but with the right steps, they could become mildly acceptable. Enjoyable even. And then again, maybe not…
Firstly though, it’s very important to realise that although maths tests can’t technically be studied for and certainly can’t be crammed for, it is possible to study for maths. It’s very much like what the language teachers say, “a little every day”. If you do, maybe one or two questions every single day, you’ll eventually find that you can do them much more efficiently and easily.
Another integral aspect of maths tests are the point allocation. You need to know what your strengths are:
1. You’re better at the skills section. In this case, by all means work the test out in order. It gives you time to perfect the skills and thus get a better mark. However, despite having less time for skills, doing analysis first would give you more opportunity to do well on this section, especially since it is usually worth more marks.
2. You’re more analysis oriented. Here, it would be ideal to do the analysis section first. It is often worth more marks, and you will have a more relaxing end to the test.
Contrary to belief, people often think analysis is harder. Teachers think that we think it’s harder too, meaning they often make numbers more convenient. The important thing with analysis is:
1. Show working out, if not for the teacher at least for yourself
2. Check everything carefully
3. If the answer is an unusual fraction, check it even more carefully
4. Draw diagrams
5. Label and USE the diagrams
Personally, I often find that skills can sometime be more difficult. They use weird numbers resulting in strange answers, so it’s difficult to tell whether you are correct or not without re-doing the whole question. Also, generally working out will not earn you any points, so careless errors are very easy to make.
Finally, I will sum this up with my top tips for maths tests:
1. Check if your teacher prefers pen or pencil
2. Show all working
3. If there is a sentence question, use a sentence answer
4. Draw and use diagrams where appropriate
5. Check everything
6. Read all questions before starting, it often calms me down
7. Revise by doing a little very often
8. Watch the time
9. If you are struggling, move on and answer it later, but don’t leave any blanks
10. My personal top tip from today’s experience: Don’t stab yourself with lead pacers where the lead may get stuck in your finger. It not only creates frightening stains on your test, but it also wastes between 10-20mins of time.
Anyway, happy testing! Or not…
ihearthorses
Unless you were sick, away, at strings, or extremely lucky, you have probably had a maths test today. It was on linear graphs; a topic which appeared to be of a quarter science, a quarter finance, a quarter maths and the rest was dot-to-dot. I’m not sure about you, but I didn’t go too well. At any rate, it has inspired this post on:
MATHS TESTS
Okay, firstly here’s a joke:
Q: How many legs does an octopus have?
A: Eight
This one was courtesy of year 5 maths. It does make you wonder, who makes these maths worksheets?
But back to the point, maths tests can be exceedingly stressful experiences, but with the right steps, they could become mildly acceptable. Enjoyable even. And then again, maybe not…
Firstly though, it’s very important to realise that although maths tests can’t technically be studied for and certainly can’t be crammed for, it is possible to study for maths. It’s very much like what the language teachers say, “a little every day”. If you do, maybe one or two questions every single day, you’ll eventually find that you can do them much more efficiently and easily.
Another integral aspect of maths tests are the point allocation. You need to know what your strengths are:
1. You’re better at the skills section. In this case, by all means work the test out in order. It gives you time to perfect the skills and thus get a better mark. However, despite having less time for skills, doing analysis first would give you more opportunity to do well on this section, especially since it is usually worth more marks.
2. You’re more analysis oriented. Here, it would be ideal to do the analysis section first. It is often worth more marks, and you will have a more relaxing end to the test.
Contrary to belief, people often think analysis is harder. Teachers think that we think it’s harder too, meaning they often make numbers more convenient. The important thing with analysis is:
1. Show working out, if not for the teacher at least for yourself
2. Check everything carefully
3. If the answer is an unusual fraction, check it even more carefully
4. Draw diagrams
5. Label and USE the diagrams
Personally, I often find that skills can sometime be more difficult. They use weird numbers resulting in strange answers, so it’s difficult to tell whether you are correct or not without re-doing the whole question. Also, generally working out will not earn you any points, so careless errors are very easy to make.
Finally, I will sum this up with my top tips for maths tests:
1. Check if your teacher prefers pen or pencil
2. Show all working
3. If there is a sentence question, use a sentence answer
4. Draw and use diagrams where appropriate
5. Check everything
6. Read all questions before starting, it often calms me down
7. Revise by doing a little very often
8. Watch the time
9. If you are struggling, move on and answer it later, but don’t leave any blanks
10. My personal top tip from today’s experience: Don’t stab yourself with lead pacers where the lead may get stuck in your finger. It not only creates frightening stains on your test, but it also wastes between 10-20mins of time.
Anyway, happy testing! Or not…
ihearthorses
Friday, July 30, 2010
Homework, Sigh
So if you check this blog regularly, which is very nice of you so thanks, you may have realised a massive gap between my last post and this one. That’s quite easily explainable; Homework Overload. Yes, it’s very much the same as last term, about six million assignments due every single day, maths test every week (such as next Friday) and whole tree’s worth of sheets and notes. I bet our school is a danger to the environment, but more importantly, I’ve decided to dedicate this post to:
HOMEWORK TIPS:
1. So to start, you need to identify what category your homework tasks fall into. Don’t worry, it doesn’t take a genius. There are only two categories: Long term, and short term.
Long term work includes: Projects, work taking over 1 week or 10hrs, all assignments, making posters, presentation preparation, research, and studying for tests,
Short term work includes: Worksheets, work with generally only 1 element, maths sums, short written works, essays, anything else that can be done or is due within a night or two.
Now that you know that, we can move on. Short-term work generally comes first for me, and is done in order of being due, then importance. Short-term homework shouldn’t take too long, but don’t skim over it either. Nicely done small tasks will make you appear ‘good’. On the other hand, long-term tasks need to be completely bit by bit, usually after short-term. Do something every day until you finish. It’s helpful to set an ‘at least time’, so you have a minimum amount of time allocated to the task. No maximum is really required, because if you get carried away you’ll end up finishing it faster.
2. Everyone needs priorities, so this is my order of importance: Food, water and oxygen (most important, obviously), compulsory or best ever activities (such as school or horse-riding), homework, optional activities, sleep. Okay, this probably won’t be the same as yours, and you might be thinking, sleep? I thought that was important. YES, sleeping is important, but when you have major geography tasks due the next day, you just can’t help but do it until one in the morning when you begin to think that you’ll either pass out or sleep over your computer (Not doing that again).
Anyway, my point is, list your priorities, rethink them, then think them again, and then do things accordingly. For example, sleep is probably a tad higher on my list.
3. Exceptions to the ‘always do homework’ rule is when the work is:
Useless repetition: Maths is a great example, over 100 questions each time of exactly the same thing over and over again can be tedious and pointless. It can be great practice, but if you know the work well, just do as much as you can. I usually use the abcdhlquyz method. It basically means do a few question, skip a few, and do some more.
Way too hard: In this case, try to do what you can, but ask a friend, sibling, parent, or nice teacher to help you. If you’re going to try using the teacher who set you the work, it would probably be good to email them or something beforehand, so if they say “why didn’t you tell me this earlier”, you can say, “I did”. Haha, or maybe not…
Set by a teacher who neither checks it nor cares: Probably not possible in most classes, but anyway, you should do the work though perhaps a bit lower on the priorities list.
So I’m not so good with homework, I just do it as soon as I get it and then hand it in. Seriously though, get it over with, and whatever you do afterward is heaps more fun. If you have anything to add, any 'sick' (haha, you know what I mean) tips, please comment!
ihearthorses
HOMEWORK TIPS:
1. So to start, you need to identify what category your homework tasks fall into. Don’t worry, it doesn’t take a genius. There are only two categories: Long term, and short term.
Long term work includes: Projects, work taking over 1 week or 10hrs, all assignments, making posters, presentation preparation, research, and studying for tests,
Short term work includes: Worksheets, work with generally only 1 element, maths sums, short written works, essays, anything else that can be done or is due within a night or two.
Now that you know that, we can move on. Short-term work generally comes first for me, and is done in order of being due, then importance. Short-term homework shouldn’t take too long, but don’t skim over it either. Nicely done small tasks will make you appear ‘good’. On the other hand, long-term tasks need to be completely bit by bit, usually after short-term. Do something every day until you finish. It’s helpful to set an ‘at least time’, so you have a minimum amount of time allocated to the task. No maximum is really required, because if you get carried away you’ll end up finishing it faster.
2. Everyone needs priorities, so this is my order of importance: Food, water and oxygen (most important, obviously), compulsory or best ever activities (such as school or horse-riding), homework, optional activities, sleep. Okay, this probably won’t be the same as yours, and you might be thinking, sleep? I thought that was important. YES, sleeping is important, but when you have major geography tasks due the next day, you just can’t help but do it until one in the morning when you begin to think that you’ll either pass out or sleep over your computer (Not doing that again).
Anyway, my point is, list your priorities, rethink them, then think them again, and then do things accordingly. For example, sleep is probably a tad higher on my list.
3. Exceptions to the ‘always do homework’ rule is when the work is:
Useless repetition: Maths is a great example, over 100 questions each time of exactly the same thing over and over again can be tedious and pointless. It can be great practice, but if you know the work well, just do as much as you can. I usually use the abcdhlquyz method. It basically means do a few question, skip a few, and do some more.
Way too hard: In this case, try to do what you can, but ask a friend, sibling, parent, or nice teacher to help you. If you’re going to try using the teacher who set you the work, it would probably be good to email them or something beforehand, so if they say “why didn’t you tell me this earlier”, you can say, “I did”. Haha, or maybe not…
Set by a teacher who neither checks it nor cares: Probably not possible in most classes, but anyway, you should do the work though perhaps a bit lower on the priorities list.
So I’m not so good with homework, I just do it as soon as I get it and then hand it in. Seriously though, get it over with, and whatever you do afterward is heaps more fun. If you have anything to add, any 'sick' (haha, you know what I mean) tips, please comment!
ihearthorses
Thursday, July 22, 2010
Chemistry Revision
Sorry this is super super super late, but here is the...
CHEMISTRY REVISION
How to safely handle acids and bases:
-Acids are corrosive, and therefore potentially dangerous
-Strong bases can also be harmful as they are caustic
-Do not combine unknown acids or bases
-Only work under supervision
-Immediately report any spills
-Do not consume any unknown substances
-Always wear safety glasses coats
-Dispose of substances as directed, not directly down the sink
-Keep away from flames unless directed
Chemical and Physical Changes:
Physical Chemical
Change of state Chemical reaction occurs
Reversible Irreversible (or difficult to do so)
Substances stay the same Form a new substance
1. Water freezing to ice 1. Some metal rusts or tarnishes
2. Dissolving sugar in water 2. Cooking
3. Melting gold 3. Vinegar and sodium bicarbonate bubbles
4. A piece of chalk is ground to dust 4. Sugar in grapes ferments
5. Glass breaks 5. Wood burns to form ash
Properties of Acids and Bases:
Acids Bases
Taste sour Taste bitter
Are corrosive Are caustic
Reacts with some metals = hydrogen React with oil so feel slippery to touch
Turn litmus red Turn litmus blue
pH is less than 7 pH is more than 7
Examples of Acids and Bases:
-Hydrochloric acid: HCl
-Sulphuric Acid: H2SO4
-Nitric Acid: HNO3
-Acetic Acid: HC2H3O2
-Sodium Hydroxide: NaOH
-Potassium Hydroxide: KOH
-Calcium Hydroxide: Ca(OH)2
-Magnesium Hydroxide: Mg(OH)2
The Use and Example of Indicators:
Indicators are used to determine whether a substance is acidic, basic (alkaline), neutral. However, the following indicators do not indicate the strength of the acid or base.
Indicator Colour in Acid Colour in Neutral Colour in Base/Alkali
Methyl Orange Reddish Orange Yellowish Yellow
Litmus (lichens) Red Green Blue
Bromothymol Blue Yellow Yellow Bluish purple
Phenolphthalein Colourless Colourless Pink
Red Wine Red Red Green
Red Cabbage Juice Red Blue Yellow
*Alkalis are bases that are soluble in water
The pH Scale and What the Numbers Indicate in Terms of Acid or Base:
-The pH scale is used the measure the strength of an acid or base
-A pH of less than 7 indicates that the substance is an acid
-A pH of more than 7 indicates that the substance is a base
-If the pH is 7, the substance is considered to be neutral – neither acid nor base
-Strong Acid: 0-3, HCl, H2SO4, HNO3
-Weak Acid: 3-7, vinegar, citric acid
-Weak Base: 7-11, Baking Soda, bicarbonate of soda
-Strong Base: 11-14, KOH, NaOH
-Universal indicator is added to substance, the colour degrees can be matched and interpreted.
Reactions of Acids and Bases:
(Reactants → Products)
1. Neutralisation: Acid + Base → Salt + Water
e.g HCl + NaOH → NaCl + H2O
2. Acid + Metal carbonate → Salt + Water + Carbon Dioxide
e.g 2HCl + CaCO3 → CaCl2 + H2O + CO2
3. Acid + Reactive metal → Salt + Hydrogen gas
e.g 2HCl + Mg → MgCl2 + H2
*Salt is a solution, so the state symbol is (aq) for aqueous. Others are (s), (l), (g)
**Test for CO2 is bubbled through limewater, hydrogen is ‘pop’ test
Interpret and Analyse Data Related to pH and acid-base:
-Remember not to put too much universal indicator
-Cloudy result means solid is made
-Bubbles or fizzing means gas is made
-In the chemical symbols, H at the beginning usually indicates an acid, and an OH at the end usually indicates a base
Acid Rain – What it is, Causes, Problems, Solutions:
- Definition:
Acid rain is any form of precipitation, such as rain or snow, which has been polluted by acids.
- Causes:
Acid rain is caused when water vapour in the air reacts with chemical compounds given off by cars, factories, and power plants (burn fossil fuels). These chemicals include Sulphur and nitrogen oxides which form into sulphuric and nitric acids.
*Carbon dioxide, which is naturally present in air, dissolves in rainwater to form a light acid
- Problems:
Acid rain directly attacks leaves and needles of plants which prevent photosynthesis. It also soaks into soil which affects chemical balance, damaging plants and crops. It can run off into rivers and lakes polluting drinking water and killing aquatic life. Acid rain also attacks stonework including buildings and statues.
- Solutions:
1. Decrease fossil fuel usage so as to limit sulphur and nitrogen compounds in the air. Find other, renewable energy sources.
2. Lime can be added to lakes in order to neutralise the acid rain.
3. Smokestacks, high tower-like chimneys, reduce local air pollution, but transfer the issue elsewhere.
Antacids in the Treatment of Indigestion:
-Your stomach contains hydrochloric acid which assists in food digestion
-When it becomes too acidic, it causes a burning feeling called indigestion
-Treatment is to take an antacid powder or tablet
-The antacid contains a base which neutralises excess acid in the stomach and relieves the pain
-Salt and water is produced
-Common antacid is milk of magnesia
-Consists of solid base, magnesium oxide suspended in water
-The base neutralises the hydrochloric acid in your stomach
magnesium oxide base + hydrochloric acid → magnesium chloride salt + water
COPYRIGHT 2010 ihearthorses
CHEMISTRY REVISION
How to safely handle acids and bases:
-Acids are corrosive, and therefore potentially dangerous
-Strong bases can also be harmful as they are caustic
-Do not combine unknown acids or bases
-Only work under supervision
-Immediately report any spills
-Do not consume any unknown substances
-Always wear safety glasses coats
-Dispose of substances as directed, not directly down the sink
-Keep away from flames unless directed
Chemical and Physical Changes:
Physical Chemical
Change of state Chemical reaction occurs
Reversible Irreversible (or difficult to do so)
Substances stay the same Form a new substance
1. Water freezing to ice 1. Some metal rusts or tarnishes
2. Dissolving sugar in water 2. Cooking
3. Melting gold 3. Vinegar and sodium bicarbonate bubbles
4. A piece of chalk is ground to dust 4. Sugar in grapes ferments
5. Glass breaks 5. Wood burns to form ash
Properties of Acids and Bases:
Acids Bases
Taste sour Taste bitter
Are corrosive Are caustic
Reacts with some metals = hydrogen React with oil so feel slippery to touch
Turn litmus red Turn litmus blue
pH is less than 7 pH is more than 7
Examples of Acids and Bases:
-Hydrochloric acid: HCl
-Sulphuric Acid: H2SO4
-Nitric Acid: HNO3
-Acetic Acid: HC2H3O2
-Sodium Hydroxide: NaOH
-Potassium Hydroxide: KOH
-Calcium Hydroxide: Ca(OH)2
-Magnesium Hydroxide: Mg(OH)2
The Use and Example of Indicators:
Indicators are used to determine whether a substance is acidic, basic (alkaline), neutral. However, the following indicators do not indicate the strength of the acid or base.
Indicator Colour in Acid Colour in Neutral Colour in Base/Alkali
Methyl Orange Reddish Orange Yellowish Yellow
Litmus (lichens) Red Green Blue
Bromothymol Blue Yellow Yellow Bluish purple
Phenolphthalein Colourless Colourless Pink
Red Wine Red Red Green
Red Cabbage Juice Red Blue Yellow
*Alkalis are bases that are soluble in water
The pH Scale and What the Numbers Indicate in Terms of Acid or Base:
-The pH scale is used the measure the strength of an acid or base
-A pH of less than 7 indicates that the substance is an acid
-A pH of more than 7 indicates that the substance is a base
-If the pH is 7, the substance is considered to be neutral – neither acid nor base
-Strong Acid: 0-3, HCl, H2SO4, HNO3
-Weak Acid: 3-7, vinegar, citric acid
-Weak Base: 7-11, Baking Soda, bicarbonate of soda
-Strong Base: 11-14, KOH, NaOH
-Universal indicator is added to substance, the colour degrees can be matched and interpreted.
Reactions of Acids and Bases:
(Reactants → Products)
1. Neutralisation: Acid + Base → Salt + Water
e.g HCl + NaOH → NaCl + H2O
2. Acid + Metal carbonate → Salt + Water + Carbon Dioxide
e.g 2HCl + CaCO3 → CaCl2 + H2O + CO2
3. Acid + Reactive metal → Salt + Hydrogen gas
e.g 2HCl + Mg → MgCl2 + H2
*Salt is a solution, so the state symbol is (aq) for aqueous. Others are (s), (l), (g)
**Test for CO2 is bubbled through limewater, hydrogen is ‘pop’ test
Interpret and Analyse Data Related to pH and acid-base:
-Remember not to put too much universal indicator
-Cloudy result means solid is made
-Bubbles or fizzing means gas is made
-In the chemical symbols, H at the beginning usually indicates an acid, and an OH at the end usually indicates a base
Acid Rain – What it is, Causes, Problems, Solutions:
- Definition:
Acid rain is any form of precipitation, such as rain or snow, which has been polluted by acids.
- Causes:
Acid rain is caused when water vapour in the air reacts with chemical compounds given off by cars, factories, and power plants (burn fossil fuels). These chemicals include Sulphur and nitrogen oxides which form into sulphuric and nitric acids.
*Carbon dioxide, which is naturally present in air, dissolves in rainwater to form a light acid
- Problems:
Acid rain directly attacks leaves and needles of plants which prevent photosynthesis. It also soaks into soil which affects chemical balance, damaging plants and crops. It can run off into rivers and lakes polluting drinking water and killing aquatic life. Acid rain also attacks stonework including buildings and statues.
- Solutions:
1. Decrease fossil fuel usage so as to limit sulphur and nitrogen compounds in the air. Find other, renewable energy sources.
2. Lime can be added to lakes in order to neutralise the acid rain.
3. Smokestacks, high tower-like chimneys, reduce local air pollution, but transfer the issue elsewhere.
Antacids in the Treatment of Indigestion:
-Your stomach contains hydrochloric acid which assists in food digestion
-When it becomes too acidic, it causes a burning feeling called indigestion
-Treatment is to take an antacid powder or tablet
-The antacid contains a base which neutralises excess acid in the stomach and relieves the pain
-Salt and water is produced
-Common antacid is milk of magnesia
-Consists of solid base, magnesium oxide suspended in water
-The base neutralises the hydrochloric acid in your stomach
magnesium oxide base + hydrochloric acid → magnesium chloride salt + water
COPYRIGHT 2010 ihearthorses
Monday, July 19, 2010
My History Essay
Hey, if any of you people out there are actually interested, here is my history essay:
ESSAY PLAN: DID RICHARD III KILL THE PRINCES?
Introduction:
Surrounded by much controversy and mystery, the question as to whether Richard III murdered the princes in the tower is one that has remained unanswered throughout history. As with any other case, there are numerous views on this particular matter. In my personal opinion though, Richard III did not kill the princes.
Paragraph 1:
To begin with, there are many pieces of evidence which depict Richard as being a devoted brother, uncle, and ruler. During the War of the Roses, by following Edward into exile, and fighting alongside him in the battles of Barnet and Tewkesbury, Richard proved his loyalty. His affection and sense of protection toward the princes may have been the cause of his failure to bring them out in public upon request. Despite the first written account of this matter being thoroughly against him, the quote, ‘he would neuer putte them to death’, quite clearly states the unlikelihood of his being the murderer. The postcards in the Battlefield Church are also proof of his fair rulings, with praise for his bravery, loyalty, and worthiness.
Paragraph 2:
Furthermore, during the Tudor’s reign, Richard was, naturally, portrayed as a villainous character with many documents supporting him destroyed, hence making later evidence likely to be biased. Due to the lack of available facts, Shakespeare’s play, ‘Richard III’, and Thomas More’s work, ‘History of King Richard III’, were largely sourced from John Morton. However, Morton himself had a low opinion of Richard III due to the fact that he had been imprisoned by Richard for treason. Therefore, these heavily biased works may have severely influenced later accounts and opinions. This effect is shown through the altered portrait of Richard III whose lips, eyes and shoulder had been modified to make him appear to be the sinister hunchback that he was not.
Paragraph 3:
Finally, there are also numerous other convincing outcomes and suspects apart from Richard III. One key suspect is Henry Tudor, whose claim to the throne was not only exceedingly unconvincing, but he did not mention the princes until over a year after Richard’s death. If alive, the princes would have been a great embarrassment to the Tudors. Another suspect is Henry Stafford, the Duke of Buckingham. While he appeared to support Richard, it was suspected that he may have been secretly assisting the Tudors. In this case, the princes’ deaths would have been of benefit. Another possible outcome was that the princes’ had in fact survived, as although their mother, Elizabeth Woodville, fought for their legitimacy, she never mentioned that they had been murdered.
Conclusion:
In conclusion, the disappearance of the princes in the tower is of high significance and mystery in history. There are many pieces of evidence which prove Richard III’s innocence, including that he had a fine personality, much of the evidence against him was biased due to the Tudor reign, and that there were numerous other likely suspects and outcomes. Therefore, the convincing evidence leads me to strongly believe that Richard III did not kill the princes.
COPYRIGHT 2010 ihearthorse
ESSAY PLAN: DID RICHARD III KILL THE PRINCES?
Introduction:
Surrounded by much controversy and mystery, the question as to whether Richard III murdered the princes in the tower is one that has remained unanswered throughout history. As with any other case, there are numerous views on this particular matter. In my personal opinion though, Richard III did not kill the princes.
Paragraph 1:
To begin with, there are many pieces of evidence which depict Richard as being a devoted brother, uncle, and ruler. During the War of the Roses, by following Edward into exile, and fighting alongside him in the battles of Barnet and Tewkesbury, Richard proved his loyalty. His affection and sense of protection toward the princes may have been the cause of his failure to bring them out in public upon request. Despite the first written account of this matter being thoroughly against him, the quote, ‘he would neuer putte them to death’, quite clearly states the unlikelihood of his being the murderer. The postcards in the Battlefield Church are also proof of his fair rulings, with praise for his bravery, loyalty, and worthiness.
Paragraph 2:
Furthermore, during the Tudor’s reign, Richard was, naturally, portrayed as a villainous character with many documents supporting him destroyed, hence making later evidence likely to be biased. Due to the lack of available facts, Shakespeare’s play, ‘Richard III’, and Thomas More’s work, ‘History of King Richard III’, were largely sourced from John Morton. However, Morton himself had a low opinion of Richard III due to the fact that he had been imprisoned by Richard for treason. Therefore, these heavily biased works may have severely influenced later accounts and opinions. This effect is shown through the altered portrait of Richard III whose lips, eyes and shoulder had been modified to make him appear to be the sinister hunchback that he was not.
Paragraph 3:
Finally, there are also numerous other convincing outcomes and suspects apart from Richard III. One key suspect is Henry Tudor, whose claim to the throne was not only exceedingly unconvincing, but he did not mention the princes until over a year after Richard’s death. If alive, the princes would have been a great embarrassment to the Tudors. Another suspect is Henry Stafford, the Duke of Buckingham. While he appeared to support Richard, it was suspected that he may have been secretly assisting the Tudors. In this case, the princes’ deaths would have been of benefit. Another possible outcome was that the princes’ had in fact survived, as although their mother, Elizabeth Woodville, fought for their legitimacy, she never mentioned that they had been murdered.
Conclusion:
In conclusion, the disappearance of the princes in the tower is of high significance and mystery in history. There are many pieces of evidence which prove Richard III’s innocence, including that he had a fine personality, much of the evidence against him was biased due to the Tudor reign, and that there were numerous other likely suspects and outcomes. Therefore, the convincing evidence leads me to strongly believe that Richard III did not kill the princes.
COPYRIGHT 2010 ihearthorse
Friday, July 16, 2010
Timed Essays
Hi everyone!
Now that school’s finally started up again, I can finally post stuff to help (or entertain) anyone who might read this blog. So, seeing as I’m in the mood after that EPIC 50min history essay on ‘Did Richard III Kill the Princes’ which I really don’t care about anyway, this post is going to be all about:
HOW TO HANDLE A TIMED ESSAY
Okay, I have to admit I’m really bad with anything that’s ‘timed’. Even in those games where the clock counts up, I get really stressed and freak out and quit the game, but unfortunately, chances are that’s not going to work in essays.
Firstly, you have to get over the fact that the time is ticking. Don’t write too quickly, and think about what you’re writing before you write it, so even if you run out of time to re-read, it shouldn’t be too bad.
Also, it always helps to know what you’re writing before-hand. If it’s a story, consider several plotlines and choose one that best fits the situation. Using dreams to end stories are NOT GOOD, as it shows you have not planned your time. However, it is better than nothing so you be the judge… Other essays can be a bit trickier to plan, unless you know the topic. If so, then write out the essay the night before, memorise it (I have a really good short-term memory but if you can’t, just try get the main points…) and write away when it’s time.
That brings me to re-reading. I know all the teachers go “re-read, re-read, re-read”, but it really depends on the type of person:
1. You are always careful when you write, rarely making silly errors, and you write slowly:
For you, I think it’s not all that important. I mean yes, by all means re-read it and check it over and over if you have time to spare, but if you’re going to cut short a good story or essay just to re-read it, then you might want to reconsider… After all, one or two small things won’t make much difference
2. You often make silly mistakes in your writing and you write very quickly:
If you’re this type of person, then the best thing you can do is RE-READ, EDIT, and RE-READ AGAIN! As long as you do that, you should be fine with most grammatical issues. But what’s that you say? You can never find spelling mistakes because they are forever playing hide and seek with you, or you just can’t remember what that silly word looks like? Simple: If you can’t find the error and have plenty of time, read the essay backwards. So instead of ‘I really like horses’ read ‘horses like really I’. You generally miss these spelling errors because your brain is focussing on something else. Reading backwards means there’s only one thing to concentrate on anyway. And if you can’t remember a single word, REPLACE IT, there are over 750 000 000 words, surely there’s one you can use instead.
3. You write quickly and accurately:
If this is you, I don’t know why you are reading this blog. Maybe you could stare out the window or something? More seriously though, if you can actually write quickly without mistakes then maybe you could expand on your ideas. Add more information, more adjectives, make improvements. I follow the improvements=((minutes remaining)/5) equation. (Okay, I may have made that up on the spot, but it does work) So you divide the amount of time after you have completed the whole essay by 5, and then make that many improvements. After you’ve done that, by all means stare out the window.
4. You write slowly and often make errors:
Okay, the only thing for you is to improve one or the other. To write quicker, write more. Yup, that’s the only way to do it. Try to see how many times you can write ‘I love horses because horses are the absolute best things ever!’ in a minute (or a sentence of your choice). While watching television, it helps if you just keep writing, for 30-50mins straight. Or, even better, be in my maths class, where we have to write and draw for 45mins straight anyway. Great practice, right?
Top Tips for Timed Essay Writing:
1. Plan and allocate time for what you are writing before-hand
2. Ignore the time while writing
3. Consider the time after writing
4. If time allows, re-read, edit, and then stare out of the window (jokes)
5. Make improvements using the improvements=((minutes remaining)/5) method
Happy writing!!
ihearthorses
PS. I’ve probably missed heaps of important stuff because I just wrote this quickly due to apparent ‘high demand’. Please comment and I can add more.
PPS. I’ll post my history essay soon, please note that all work on here is COPYRIGHT!
Now that school’s finally started up again, I can finally post stuff to help (or entertain) anyone who might read this blog. So, seeing as I’m in the mood after that EPIC 50min history essay on ‘Did Richard III Kill the Princes’ which I really don’t care about anyway, this post is going to be all about:
HOW TO HANDLE A TIMED ESSAY
Okay, I have to admit I’m really bad with anything that’s ‘timed’. Even in those games where the clock counts up, I get really stressed and freak out and quit the game, but unfortunately, chances are that’s not going to work in essays.
Firstly, you have to get over the fact that the time is ticking. Don’t write too quickly, and think about what you’re writing before you write it, so even if you run out of time to re-read, it shouldn’t be too bad.
Also, it always helps to know what you’re writing before-hand. If it’s a story, consider several plotlines and choose one that best fits the situation. Using dreams to end stories are NOT GOOD, as it shows you have not planned your time. However, it is better than nothing so you be the judge… Other essays can be a bit trickier to plan, unless you know the topic. If so, then write out the essay the night before, memorise it (I have a really good short-term memory but if you can’t, just try get the main points…) and write away when it’s time.
That brings me to re-reading. I know all the teachers go “re-read, re-read, re-read”, but it really depends on the type of person:
1. You are always careful when you write, rarely making silly errors, and you write slowly:
For you, I think it’s not all that important. I mean yes, by all means re-read it and check it over and over if you have time to spare, but if you’re going to cut short a good story or essay just to re-read it, then you might want to reconsider… After all, one or two small things won’t make much difference
2. You often make silly mistakes in your writing and you write very quickly:
If you’re this type of person, then the best thing you can do is RE-READ, EDIT, and RE-READ AGAIN! As long as you do that, you should be fine with most grammatical issues. But what’s that you say? You can never find spelling mistakes because they are forever playing hide and seek with you, or you just can’t remember what that silly word looks like? Simple: If you can’t find the error and have plenty of time, read the essay backwards. So instead of ‘I really like horses’ read ‘horses like really I’. You generally miss these spelling errors because your brain is focussing on something else. Reading backwards means there’s only one thing to concentrate on anyway. And if you can’t remember a single word, REPLACE IT, there are over 750 000 000 words, surely there’s one you can use instead.
3. You write quickly and accurately:
If this is you, I don’t know why you are reading this blog. Maybe you could stare out the window or something? More seriously though, if you can actually write quickly without mistakes then maybe you could expand on your ideas. Add more information, more adjectives, make improvements. I follow the improvements=((minutes remaining)/5) equation. (Okay, I may have made that up on the spot, but it does work) So you divide the amount of time after you have completed the whole essay by 5, and then make that many improvements. After you’ve done that, by all means stare out the window.
4. You write slowly and often make errors:
Okay, the only thing for you is to improve one or the other. To write quicker, write more. Yup, that’s the only way to do it. Try to see how many times you can write ‘I love horses because horses are the absolute best things ever!’ in a minute (or a sentence of your choice). While watching television, it helps if you just keep writing, for 30-50mins straight. Or, even better, be in my maths class, where we have to write and draw for 45mins straight anyway. Great practice, right?
Top Tips for Timed Essay Writing:
1. Plan and allocate time for what you are writing before-hand
2. Ignore the time while writing
3. Consider the time after writing
4. If time allows, re-read, edit, and then stare out of the window (jokes)
5. Make improvements using the improvements=((minutes remaining)/5) method
Happy writing!!
ihearthorses
PS. I’ve probably missed heaps of important stuff because I just wrote this quickly due to apparent ‘high demand’. Please comment and I can add more.
PPS. I’ll post my history essay soon, please note that all work on here is COPYRIGHT!
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