T8 Testing for Gases and Water

Question 1

How to test for Ammonia?

Answer 1

Damp red litmus paper -> goes blue

Question 2

How to test for carbon dioxide?

Answer 2

Bubble through lime water -> goes cloudy, white precipitate forms

Question 3

How to test for chlorine?

Answer 3

Damp blue litmus paper -> goes red then bleaches white

Question 4

What is the test for hydrogen?

Answer 4

Put a lit splint in the gas -> if hydrogen, goes out with a squeaky pop

Question 5

What is the test for oxygen?

Answer 5

Put a glowing splint in the gas -> if oxygen, splint relights

Question 6

Describe the physical test for pure water

Answer 6

• A sample of the liquid is placed in a suitable container such as a boiling tube and gently heated
• Using a thermometer, you can check if the boiling point is exactly 100 oC
• Any impurities present will usually tend to raise the boiling point and depress the melting point of pure substance

Question 7

What is the chemical test for water

Answer 7

Anhydrous copper(II) sulfate turns from white to blue on the addition of water

Question 8

What is the equation for the chemical test for water

Answer 8

CuSO4 (s) + 5H2O (l) → CuSO4.5H2O (s)

Question 9

What is the appearance of ammonia

Answer 9

colourless, pungent smell

Question 10

What is the appearance of carbon dioxide

Answer 10

colourless, odourless

Question 11

What is the appearance of chlorine

Answer 11

pale green, choking smell

Question 12

What is the appearance of hydrogen

Answer 12

colourless, odourless

Question 13

What is the appearance of oxygen

Answer 13

colourless, odourless