Testing pH
Aim: To test the pH of a ranged of household chemicals.
Equipment:
A variety of household chemicals, spotting tile, red litmus paper, blue litmus paper, Universal indicator solution, safety glasses.
A variety of household chemicals, spotting tile, red litmus paper, blue litmus paper, Universal indicator solution, safety glasses.
Method:
1. Add a few drops of each chemical to a spot on your spotting tile. If a substance is solid or powdered you will need to mix it with a few drops of water before testing it.
2. Test the chemicals with litmus paper.
3. Test each chemical with a few drops of Universal Indicator.
Results:
Conclusion:
Toilet cleaner is neutral based on the lithmus paper, but the pH level is slightly acidic (maybe we did something wrong, the results conflicts).
Clean & Dust Spray also conflicts with the pH level and the lithmus paper (we thought the lithmus papers and universal indicator are fake, nope just kidding).
The bleach turned out to be a strong base solution. (So be careful using bleach, it can burn your skin or itchy and irritated)
The multi-purpose cleaner is slightly acidic. (Do you have this at your home?)
Dishwashing Liquid is neutral. (You don't have any excuse to not wash your dishes, or else you have allergies)
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May 4, 2018
Neutralisation
Equipment:
A test tube, test rack, 1 mol L -1 NH4OH (Ammonium hydroxide), 1 mol L -1 H2SO4 (sulfuric acid), dropper or dropper bottle, Universal indicator solution.
Method:
1. Add approximately 1-2 mL of NH4OH and place the test tube into the test tube rack. Add 3-5 drops of Universal indicator solution.
2. Using a dropper bottle, add H2SO4 drop by drop. Be careful because adding even a small amount of extra acid can mean you'll miss the neutralisation.
In this experiment instead of sodium carbonate and hydrochloric acid we used sulfuric acid and ammonium hydroxide as the base.
(from the left)
1st test tube: Containing 2 mL of sulfuric acid and 5 drops of Universal indicator that showed a red colour that means it's a strong acid.
3rd test tube: Containing 2 ml of Ammonium hydroxide and drops of Universal indicator and we observed a strong blue colour that tells it's basic. We put 2 drops of sulfuric acid and it turned yellowish, skipped the neutralisation and made it slightly acidic.
4th test tube: We put 2 mL of Ammonium hydroxide and 5 drops of Universal indicator. Then slowly dropped a very small amount of sulfuric acid and nothing happened and did the same thing for 2 times and slowly as we stir it turned green Finally we neutralised the solution.
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May 9, 2018
Experimental
Aim: To make chemical reactions using baking soda, vinegar and a dishwashing a liquid as variables.
Equipment:
Baking Soda, vinegar, dishwashing liquid, test tube, 50 mL beaker, spatula
Method:
Put a small amount of baking soda on the test tube. Then pour the vinegar using beaker. Try it with putting dishwashing liquid. You could also try changing the amount of the variables and see what happens.
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May 10, 2018
Making Salts
Aim: To produce sodium chloride salt by carrying out a neutralisation reaction.Equipment:
50 mL and 200 mL beakers, dilute HCl (hydrochloric acid), dilute NaOH (sodium hydroxide), 25 mL measuring cylinder, a glass stirring rod, spotting tile, Universal indicator solution, tripod, gauze mat, Bunsen burner, evaporating basin.
Method:
1. Using the measuring cylinder measure 10 mL of HCl and pour it into your 50 mL beaker. Add dilute NaOH a few drops at a time while stirring with a glass rod.
2. Every 10-15 drops stop adding the NaOH ad use the glass stirring rod to transfer a drop of the solution to a spotting tile. Test its pH using Universal indicator.
3. Keep adding NaOH and testing the solution by repeating step 2. AS you get closer to neutral you may test the solution after every drop.
4. Pour the neutral solution into an evaporating basin and evaporate the water out of the solution using the equipment set up shown above.
Observations:
I infer that neutralising NaOH and HCl is very tricky and difficult. One small extra drop can skip the pH level 7.
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May 10, 2018
Making Salts II
Aim: To produce a copper sulfate salt by reacting copper oxide with an acid.
Equipment:
Copper oxide powder, dilute (3.5 mol L-4) sulfuric acid, 50 mL measuring cylinder, two 100 mL beakers, Bunsen burner, tripod, gauze mat, funnel, filter paper, thermometer, spatula, evaporating basin, stirring rod.
Method:
1. Add 2 mL of sulfuric acid to a 100 mL beaker. Heat the acid until it reaches 70℃. Turn off your Bunsen burner.
2. Once heated, use a spatula to add a pea-sized portions of copper oxide to the beaker. Stir the mixture for 30 seconds.
3. Repeat step 2 until no more will dissolve, Allow the beaker to cool.
4. Fold the filter paper and place it in the funnel. Place the filter funnel into the second beaker.
5. Make sure the beaker is cool enough to hold at the top. The contents should still be hot. You may need your teacher to complete this step.
6. Slowly swirl the contents of the beaker to mix, and then pour into the filter paper in the funnel. Allow to filter through.
7. Rinse the beaker you used to heat the mixture previously, and place back on top of tripod filled with 50-60 mL of water.
8. Place the evaporating basin on top of the beaker and carefully pour some of the solution from the beaker into the evaporating basin.
9. Gently heat the beaker until the solution in the evaporating basin has reduced by half.
10. Leave the evaporating basin to cool. Once cool, move the evaporating basin to a warm place where it will not be disturbed (i.e, a window-still) and observe over the next few days. Blue copper sulfate crystals should form.
Observations:
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My 14, 2018
Making Indicators
Aim: To make acid-base indicators using everyday substances.
Equipment:
Red Cabbage, Tea, beetroot, TURMERIC, PURE ALCOHOL, CRANBERRY JUICE, BEAKER, water, Bunsen burner, tripod, gauze mat, 1.0 mol L-1 HCl nd mol L-1 NaOH.
Observations:
Turmeric is a bit confusing because when we tested Hydrochloric acid to it, it shows a yellow colour and the same as sodium hydroxide that shows a yellow orange colour so I can't trust this indicator so much.
Cranberry Juice and cabbage has the same results wherein hydrochloric acid, red, and sodium hydroxide, green.
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May 24, 2018
Metals and Acids
Aim: To show that hydrogen gas is produced when a metal reacts with acid
Equipment:
A test tube, a boiling tube, Bunsen burner, wooden splint, a bottle of acid, a piece of metal (we used magnesium), safety glasses.
Method:
1. Light your Bunsen burner.
2. Add your sample of metal to your test tube, add 2 mL of acid.
3. Carefully invert the boiling test tube containing the metal and acid (as shown in the diagram below).
4. Hold the test tubes for a few minutes, allowing time for the inverted boiling tube to fill with gas.
5. When you think the tube is full, your lab partner should light a wooden splint.
6. Carefully, but quickly, tilt the boiling tube full of gas upwards and insert the burning splint into the mouth of the test tube.
Observations:
Quick senses and hands are required to do this experiment successfully. I always have a great cooperation with Alyana doing tasks. Hydrogen was produced when hydrochloric acid and magnesium metal are combined, we collected the gas on a boiling tube, quickly and carefully putting the fire inside the tube containing hydrogen made a cute sound POOF! (Warning! It hurt my ears a little)
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May 25, 2018
Making Metal Oxide
Aim: To make a metal oxide and observe the difference in properties of the product compared to the reactants.
Equipment:
A piece of magnesium, iron and copper, Bunsen Burner, safety glasses, metal scissor tongs.
Method:
1. Light your Bunsen burner.
2. Hold your piece of magnesium in the scissor tongs. Ensure you are holding onto the very tip of the magnesium.
3. Place the other end of the magnesium into the Bunsen flame (at the top of the blue flame)
4. When the magnesium begins to burn, do not look directly at it, as the light emitted can permanently damage your eyes.
Results:
Observations:
Fire uses oxygen to burn so oxidation occurs.
Magnesium + Oxygen →Magnesium Oxide
As it burns, it also produces a really bright white light so looking directly at it is restricted cause it will too much light for our eyes will damage it permanently, just like when you stare at the sun for too long. The magnesium metal became white residue afterwards, it is very corrosive.
Iron + Oxygen →Iron Oxide
Iron gives a wonderful effect when put to blue flame, the tip flame on the metal becomes bright blue. The metal became black after putted on the flame that tells somehow it burnt.
Copper + Oxygen →Copper Oxide
When put on the blue flame, it looks like the flame is avoiding it. The copper's shape also got curved a bit.
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May 30, 2018
Testing for Carbon Dioxide Gas
Aim: To show that carbon dioxide gas is produced when a metal carbonate reacts with acid.
Equipment:
Two boiling tubes, delivery tube and bung, Bunsen burner, test tube rack, wooden splint, a bottle of acid, small amount of metal carbonate, test tube tongs, safety glasses.
Method:
1. Light your Bunsen burner.
2. Add a pea-sized amount of metal carbonate into one of the boiling tubes.
3. Place this boiling tube into a test tube rack. Ensure you have the bung and delivery tube ready.
4. Add 5 mL of acid to the boiling tube and quickly insert the bung and delivery tube into the mouth of the boiling tube.
5. Holding the other boiling tube with your tongs, capture the gas produced as shown in the diagram below
6. When you think the tube is full, your lab partner should light a wooden splint.
7. Carefully remover the boiling tube from under the delivery tube, taking care to keep it facing upright.
8. Insert the burning splint into the mouth of the test tube.
Observations:
The fire on the splint got extinguished due to the presence of carbon dioxide.
We also did this experiment with limewater (calcium hydroxide)
Bubble gas into limewater (calcium hydroxide)
Solution turned from colourless to cloudy.
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May 31, 2018
Aim: To make hokey pokey and eat it.
Ingredients
100 g of sugar
1 table spoon of water
2 table spoon of golden syrup
1 teaspoon of bicarbonate of soda
Method:
1. Put of the ingredients except the bicarbonate of soda into a saucepan and place on a low heat.
2. Stir until all the sugar has dissolved. Raise the heat slightly so that it bubbles, and stir occasionally until you cannot feel any sugar at the bottom of the pan.
3. Take off the heat.
4. Add bicarbonate of soda and stir.
5. Watch what happens - it should all froth up with bubbles in the pan.
6. Pour out into tinfoil sheet.
7. Allow to cool.
Making Hokey Pokey
Aim: To make hokey pokey and eat it.
Ingredients
100 g of sugar
1 table spoon of water
2 table spoon of golden syrup
1 teaspoon of bicarbonate of soda
Method:
1. Put of the ingredients except the bicarbonate of soda into a saucepan and place on a low heat.
2. Stir until all the sugar has dissolved. Raise the heat slightly so that it bubbles, and stir occasionally until you cannot feel any sugar at the bottom of the pan.
3. Take off the heat.
4. Add bicarbonate of soda and stir.
5. Watch what happens - it should all froth up with bubbles in the pan.
6. Pour out into tinfoil sheet.
7. Allow to cool.
Believe it or not, this is hokey pokey ↑ (well basically, it's not yet but turning into)
Stirring it makes it really hard because of the sticky texture but at the end it gave us a very soothing taste honey!
Stirring it makes it really hard because of the sticky texture but at the end it gave us a very soothing taste honey!
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June 1, 2018
Corrosion
Investigating Rusting
Aim: To investigate the factors that cause rusting in iron.
Equipment:
Six test tubes, test tube rack, a bung, 6 iron nails, tap water, salt water, water+oil, Mg ribbon wrapped around, water+calcium chloride, bung, nail polish.
Method:
1. Label the test tubes with contents in a test tube rack
2. Test Tube contents
A = Tap Water and iron nail
B = Salt water and iron nail
C = water + oil and iron nail
D = Mg ribbon wrapped around iron nail
E = Water, calcium chloride and iron nail
F = Iron nail with nail polished
3. Leave the test tubes undisturbed for at least three days.
Observations:
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