Q Tests

Question 1

What’s the test for H2 gas?

Answer 1

Gives a pop with a burning splint

Question 2

What’s the test for O2 gas?

Answer 2

Relights a glowing splint

Question 3

What’s the test for Cl2 gas?

Answer 3

Bleaches damp litmus paper/universal indicator paper

Question 4

What’s the test for HCl gas?

Answer 4

Glass rod dipped in conc ammonia solution gives off white fumes

Question 5

What’s the test for NH3 gas?

Answer 5

Glass rod dipped in conc HCl gives off white fumes

Question 6

What is the flame colour of Li+?

Answer 6

Crimson

Question 7

What is the flame colour of Na+?

Answer 7

Yellow/orange

Question 8

What is the flame colour of K+?

Answer 8

Lilac

Question 9

What is the flame colour of Ca2+?

Answer 9

Brick red/red

Question 10

What is the flame colour of Ba2+?

Answer 10

Green

Question 11

What is the flame colour of Cu2+?

Answer 11

Blue-green

Question 12

What is the test for NH4+?

Answer 12

Warm with a solution of NaOH.
Pungent smell observed

Question 13

What is the test for SO4 2-?

Answer 13

Make a solution and add a solution of barium chloride - forms a white precipitate.

Question 14

How do you test for halide ions?

Answer 14

Make a solution in dilute nitric acid
Add silver nitrate solution
Note observations for each halide ion.

Question 15

What colour is Cl- precipitate? Is it soluble?

Answer 15

White precipitate
Soluble in dilute ammonia solution

Question 16

What colour is Br- precipitate? Is it soluble?

Answer 16

Cream precipitate
Soluble in conc ammonia solution

Question 17

What colour is I- precipitate? Is it soluble?

Answer 17

Yellow precipitate
Insoluble in conc ammonia solution

Question 18

What’s the test for a carbonate ion?

Answer 18

Add dilute acid to form colourless gas which turns limewater milky .

Question 19

What’s the test for iodine?

Answer 19

Add a few drops of starch to the solution
Solution will turn blue-black.