Test for Anions

Question 1

What is the Law of conservation of mass

Answer 1

The total mass of products of a chemical reaction is the same as the total mass of the reactants

Question 2

What is the Law of Conservation of Matter

Answer 2

Matter cannot be created nor destroyed, only changed from one form to another

Question 3

Describe an experiment to test for anions in chloride salt

Answer 3

1. Fill 1/4 of a test use with deionised water
2. Add a few crystals of chloride salt
3. Shake to dissolve
4. Using a dropper add a small amount of silver nitrate
5. A white cloudy precipitate should appear
6. Add ammonia solution to fume hood
7. Precipitate should go colourless

Question 4

Describe an experiment to test for anions using Nitrate(N03)

Answer 4

1. Add nitrate salt to 1/4 test tube of demonised water
2. Shake to dissolve
3. Add 1/4 test tube of iron sulphate
4. In a fume hood add 3cm of concentrated sulphuric acid down the side of the slanted test tube
5. A brown ring should appear in the middle of the two liquids

Question 5

Describe an experiment to test for anions in Phosphate(PO4) salt

Answer 5

1. Add phosphate salt to 1/4 test tube of deionised water
2. Shake to dissolve
3. Add 1/2 test tube of ammonia molybdate to it
4. In fume hood add 5 drops of concentrated nitric acid down the side
5. A yellow precipitate should be formed
6. If not formed, heat to 60 degrees in water bath

Question 6

Describe a test for Sulphates(SO4) and Sulphites(SO3)

Answer 6

1. Add 1/4 test tube of deionised water wand a few salt crystals
2. Shake to dissolve
3. Add barium chloride
4. Both the sulphate and sulphite should produce a white precipitate
5. Add ccl to both
6. The sulphite precipitate should disappear, while the sulphate should stay the same

Question 7

Describe an experiment to test for Carbonate(C03) and Hydrogencarbonates(HCO3)

Answer 7

1. Place 1cm of either salt in test tube
2. Set up stopper on test tube, with a tube connecting into conical flask of limewater
3. Add 1/4 test tube of hcl to test tube
4. Fizzing should turn limewater milky

Question 8

Describe an experiment to test for C03 separately

Answer 8

1. Add Carbonate salt to 1/4 test tube of deionised water
2. Add 1/4 test tube of magnesium sulphate
3. A white precipitate should be observed

Question 9

Describe an experiment to test the presence of Hydrogencarbonates

Answer 9

1. Salt added to 1/4 deionised water
2. Add 1/4 test tube of magnesium sulphate
3. There should be no change unless heated, which would give a white precipitate