Chemical Analysis

Question 1

What is a precipitation reaction

Answer 1

When 2 (aq) solutions are reacted together to make an insoluble salt.

Question 2

What test would you use to identify what metal was in a substance

Answer 2

Flame test

Question 3

How do you test for oxygen gas

Answer 3

Place a glowing splint in the test tube filled with oxygen - it should relight

Question 4

How do you test for hydrogen gas

Answer 4

Place a lit splint over a test tube of hydrogen - you should hear a squeaky pop

Question 5

How do you test for CO2

Answer 5

Add lime water - will go from colourless to cloudy

Question 6

How do you test for a carbonate

Answer 6

Adding hydrochloric acid to a carbonate will cause it to bubble.

Carbon dioxide gas is then released and collected.

Therefore we can add lime water to the solution and it will turn cloudy, due to the present CO2.

Question 7

How do you test for a sulphate

Answer 7

You should first add a few drops of HCl, then a few drops of barium chloride.

A white participate of barium sulphate should form, if the sulphate ions are present.

Question 8

How do you make an insoluble salt?

Answer 8

Precipitation reaction

Question 9

How do you make a soluble salt?

Answer 9

You can react acids with many different things to create soluble salts:
Metal + acid -> salt + hydrogen
Metal oxide + acid -> salt + water
Metal hydroxide + acid -> salt + water
Metal carbonate + acid -> salt + water + carbon dioxide