Analysis

Question 1

What metal ions are present when the flame turns crimson red?

Answer 1

Lithium

Question 2

What metal ions are present when the flame turns yellow?

Answer 2

Sodium

Question 3

What metal ions are present when the flame turns lilac?

Answer 3

Potassium

Question 4

What metal ions are present when the flame turns brick red?

Answer 4

Calcium

Question 5

What is the test for hydrogen?

Answer 5

Gives a squeaky pop with a lighted spill

Question 6

What is the test for oxygen?

Answer 6

Relights a glowing splint

Question 7

What is the test for carbon dioxide?

Answer 7

Turns limewater cloudy

Question 8

What is the test for chlorine?

Answer 8

Bleaches damp litmus paper

Question 9

What is the test for ammonia?

Answer 9

Turns damp red litmus paper blue

Question 10

What is the test when using sodium hydroxide?

Answer 10

Add a few drops of sodium hydroxide to the solution being tested

Question 11

What is the colour of the precipitate when copper ions are present?

Answer 11

Blue

Question 12

What is the colour of the precipitate when iron (II) ions are present?

Answer 12

Green

Question 13

What is the colour of the precipitate when iron (III) ions are present?

Answer 13

Rust

Question 14

What is the test for identifying sulphate ions?

Answer 14

Add a few drops of hydrochloric acid followed by barium chloride solution

Question 15

How do you test for ammonium ions?

Answer 15

Add aqueous sodium hydroxide to the sample and gently warm the mixture. A pungent-smelling gas is produced if ammonium ions are present. The gas produced turns damp red litmus paper blue. This gas is ammonium, NH3.

Question 16

When the colour of the precipitate is white, what halide ion is present?

Answer 16

Silver chloride

Question 17

When the colour of the precipitate is cream, what halide ion is present?

Answer 17

Silver bromide

Question 18

When the colour of the precipitate is yellow, what halide ion is present?

Answer 18

Silver iodide

Question 19

How do you carry out the flame test for positive ions?

Answer 19

1) Put a small amount of the compound to be tested in a nichrome wire loop. (First the wire loop should be dipped in concentrated hydrochloric acid and heated to clean it. Then it should be dipped in the acid again before dipping in the compound).
2) Hold the loop in the roaring blue flame of a Bunsen burner.
3) Use the colour of the Bunsen flame to identify the metal ion in the compound

Question 20

What is the test for ammonia gas?

Answer 20

Ammonia will form a white smoke in the presence of hydrogen chloride gas, HCl. The white smoke is ammonium chloride, NH4Cl.