Gas Chemistry

Question 1

How much % of the air does nitrogen make up in the air

Answer 1

78%

Question 2

How much % of the air does Oxygen make up in the air

Answer 2

21%

Question 3

How much % of the air does Carbon Dioxide make up in the air

Answer 3

0.03% (increasing towards 0.04%)

Question 4

How much % of the air does Argon make up in the air

Answer 4

0.9%

Question 5

How much % of the air does Other Noble Gases make up in the air

Answer 5

0.07%

Question 6

How much % of the air does Water Vapour make up in the air

Answer 6

Trace

Question 7

What is nitrogen

Answer 7

Nitrogen exists as a diatomic gas and is bonded covalently with a triple covalent bond

Question 8

Properties of nitrogen

Answer 8

Colourless
Odourless
Not very reactive

Question 9

Uses of Nitrogen

Answer 9

In Food packaging to keep food fresh
Manufacture of Ammonia
Liquid Nitrogen is used as a refrigerant

Question 10

What is amonia

Answer 10

Gas at room temperature and used in manufacture of:
Fertilisers
Nitric acid
Nylon

Question 11

How can you test for ammonia

Answer 11

Ammonia and hydrochloric acid can be used to test for each other. If a glass rod is dipped into one solution and held above the other solution, a white cloud will form.

Question 12

How are fertilisers formed

Answer 12

By using an acid + alkali reaction with ammonia

Ammonia + Sulfuric Acid = Ammonium Sulfate
2NH3 + H2SO4 = (NH4)2SO4

Question 13

What is Hydrogen

Answer 13

Exists as a diatomic gas and is bonded covalently

Question 14

Properties of Hydrogen

Answer 14

Odourless
Colourless
Insoluble in water
Lighter than air
Strong Reducing Agent
Flammable

Question 15

Uses of Hydrogen

Answer 15

Rocket Fuel
Clean Fuel
Meteorological balloons
Production of Ammonia

Question 16

How can hydrogen be prepared

Answer 16

Reacting an acid and a metal
Zinc + Hydrochloric Acid = Zinc Chloride + Hydrogen
Zn + 2HCl = ZnCl2 + H2

Question 17

How can hydrogen be collected

Answer 17

dry test tube by upward displacement
Hydrogen, being lighter than air, rises and pushes the air out of the test tube. Eventually, the test tube becomes filled with hydrogen.

Question 18

Hydrogen reaction with Oxygen

Answer 18

Hydrogen burns in oxygen to form water
Exothermic reaction
Means that it has potential as a clean fuel as it doesn’t give off any harmful gases
2H2 + O2 = 2H2O

Question 19

Whats a clean fuel

Answer 19

One which produces non-polluting products only (such as water) when its burned

Question 20

What is oxygen

Answer 20

Exists as a diatomic gas and is bonded covalently with a double covalent bond

Question 21

Properties of Oxygen

Answer 21

Colourless
Odourless
Soluble in water
Flammable

Question 22

Uses of oxygen

Answer 22

Breathing apparatus in hospitals or for divers
Welding
Making steel
Rocket Fuel

Question 23

What is a catalyst

Answer 23

Substance which speeds up a reaction without being used up itself

Question 24

What happens when carbon burns in oxygen

Answer 24

Glows red hot
Colourless gas of carbon dioxide produced
C + O2 = CO2

Question 25

What happens when sulphur burns in oxygen

Answer 25

Burns with a blue flame Colourless gas of sulphur dioxide produced S + O2 = SO2

Question 26

What happens when metals burn in oxygen

Answer 26

Produce basic oxides

Question 27

What happens when magnesium burns in oxygen

Answer 27

Burns with a bright white light White ash of magnesium oxide is left 2Mg + O2 = 2MgO

Question 28

What happens when Iron (II) burns in oxygen

Answer 28

Burns with sparks Turns black 2Fe + O2 = 2FeO

Question 29

Wat happens when Copper burns in oxygen

Answer 29

Turns black as Copper Oxide is formed 2Cu + O2 = 2CuO

Question 30

What is carbon dioxide

Answer 30

Carbon is in the centre of the molecule bonded to two oxygen atoms by two double covalent bonds

Question 31

what are the properties of carbon dioxide

Answer 31

Odourless Colourless Slightly soluble in water Doesn't burn Sublimes Heavier than air

Question 32

what are the uses of Carbon Dioxide

Answer 32

Fizzy Drinks Fire extinguishers Dry Ice (smoke effects on stage)

Question 33

How can carbon dioxide be prepared

Answer 33

Reacting an acid and a carbonate

Question 34

Carbon dioxide reaction with water

Answer 34

Carbon dioxide dissolves in water and reacts to give wear carbonic acid CO2 + H2O = H2CO3

Question 35

Carbon dioxide reaction with Limewater

Answer 35

Limewater is colourless solution of calcium hydroxide when CO2 is bubbled through it, reacts to form calcium carbonate precipitate causing cloudy appearance CO2 (g) + Ca(OH)2 (aq) = CaCO3 (s) + H2O (l) If you continue to pass an excess of carbon dioxide through the cloudy limewater, it will change back to colourless, as soluble calcium hydrogen carbonate is formed CO 2 (g) + CaCO 3 (s) + H 2 O (l) ⇌ Ca(HCO 3 ) 2 (aq)