Gas Chemistry

Question 1

What is the percentage of Nitrogen in the atmosphere?

Answer 1

78%

Question 2

What is the percentage of oxygen in the atmosphere?

Answer 2

21%

Question 3

What is the percentage of argon in the atmosphere?

Answer 3

1%

Question 4

What is the percentage of carbon dioxide in the atmosphere?

Answer 4

0.03-0.04%

Question 5

What are the physical properties of Nitrogen? (3)

Answer 5

• colourless, odourless gas
• neutral
• insoluble in water

Question 6

What are the industrial uses of nitrogen?

Answer 6

• food packaging
• liquid nitrogen as a coolant in refrigerated lorries

Question 7

What are the physical properties of oxygen? (3)

Answer 7

• colourless, odourless gas
• neutral
• slightly soluble in water

Question 8

What are the industrial uses of oxygen?

Answer 8

• welding
• medicine (breathing issues)

Question 9

What are the physical properties of ammonia? (3)

Answer 9

• pungent gas
• soluble base
• weak alkali

Question 10

What is the test for oxygen?

Answer 10

If a glowing splint relights

Question 11

What is the test for ammonia? (3)

must know

Answer 11

• hold a hot glass rod
• dipped in concentrated HCl
• White smoke forms

Question 12

What is the balanced symbol equation for the reaction between NH₃ and HCl?

Answer 12

NH₃ + HCl —> NH₄Cl

Question 13

What is the industrial use of ammonia?

Answer 13

Used to make fertilisers - through ammonium salts

Question 14

How is ammonia formed?

Give a symbol equation for this reaction

Answer 14

• Via the HABER process
• N₂ + 3H₂ <—> 2NH₃ (reaction is reversible)

Question 15

What are the physical properties of carbon dioxide? (3)

Answer 15

• colourless, odourless gas
• slightly soluble in water
• denser than air

Question 16

What are the industrial uses of carbon dioxide?

Answer 16

• used to make carbonic acid in fizzy drinks
• fire extinguishers

Question 17

What is the test for carbon dioxide?

What happens when CO₂ is in excess? (4)

Give balanced symbol equations with state symbols

Answer 17

• bubble through limewater
• colourless to milky
• CO_{2 (g)} + Ca(OH)_{2 (aq)} —> CaCO_{3 (s)} + H₂O_(l)
• if in excess - colourless solution formed —> H₂O_(l) + CaCO_{3 (s)} +CO_{2 (g)} —> Ca(HCO₃)_{2 (aq)}

Question 18

What are the physical properties of hydrogen? (4)

Answer 18

• colourless, odourless gas
• insoluble in water
• less dense than air
• neutral

Question 19

What is the test for hydrogen?

Answer 19

lit splint causes a squeaky pop

Question 20

What are the industrial uses of hydrogen?

Answer 20

• weather balloons
• hardening oils

+ can be used as a green fuel

Question 21

How do you work out atom economy?

Answer 21

(Mr of desired product ÷ total Mr of products) x 100

Question 22

What apparatus and reagents are used to collect hydrogen? (8)

Answer 22

Apparatus:

• gas chamber
• beehive shelf
• trough of water (above beehive shelf)
• delivery tube (into beehive shelf)
• conical flask
• thistle funnel

Reagents:

• zinc
• hydrochloric acid

Question 23

What apparatus and reagents are used to collect oxygen? (8)

Answer 23

Apparatus:

• gas chamber
• beehive shelf
• trough of water (above beehive shelf)
• delivery tube (into beehive shelf)
• conical flask
• thistle funnel

Reagents:

• manganese (IV) oxide / Manganese dioxide
• hydrogen peroxide

Question 24

What apparatus and reagents are used to collect carbon dioxide? (8)

Answer 24

Apparatus:

• gas chamber
• beehive shelf
• trough of water (above beehive shelf)
• delivery tube (into beehive shelf)
• conical flask
• thistle funnel

Reagents:

• calcium carbonate
• hydrochloric acid

Question 25

What type of substance are:

• metal oxides
• non-metal oxides

Answer 25

• basic
• acidic

Question 26

Why is nitrogen so unreactive?

Answer 26

Strong triple covalent bond