Air and Pollution 🧪

Question 1

What is air a mixture of?

Answer 1

N2 78%
O2 21%
CO2 0.03-0.04%
All other gases (mainly Ar, Inert gases, Water Vapour and Dust) 1%

Question 2

How is O2 obtained from air?

Answer 2

Dust is removed in a filter, air is compressed then allowed to expand from liquified air by fractional distillation oxygen is obtained

Question 3

What happens when air is compressed then allowed to expand?

Answer 3

Water vapour is condensed and then freezes
Carbon dioxide becomes dry ice

Question 4

What are polluted gases?

Answer 4

CH4 CO SO2 Hydrocarbons NO NO2

Question 5

What gases do industries (coal) produce?

Answer 5

CO SO2 Nitrogen oxides

Question 6

What gases do Vehicles produce?

Answer 6

Hydrocarbons, CO

Question 7

How to remove SO2?

Answer 7

Ca(OH)2 aq lime water is sprayed neutralization reaction with SO2

Question 8

How to remove CO NO NO2 and hydrocarbons?

Answer 8

Can be removed by fixing a catalytic converter which contains Pt and Rh catalysts. Fixed in the car exhaust pipe

Question 9

What does a catalytic converter do?

Answer 9

Reactions take place and toxic gases which enter the converter come out as safe gases

Question 10

What reactions take place in a catalytic converter?

Answer 10

2CO + O2 —> 2CO2
2CO + 2NO —> N2 + 2CO2
CxHy + O2 —> CO2 + H2O

Question 11

How are oxides of Nitrogen produced in a vehicle?

Answer 11

When the engine heats up N2 combines with O2 in the air inside the engine to form oxides of nitrogen

Question 12

When the vehicle runs for a short distance why are no Nitrogen oxides produced?

Answer 12

Engine doesn’t heat up enough, optimum temperature isn’t reached

Question 13

What are the greenhouse gases?

Answer 13

CO2
CH4
SO2

Question 14

What ability do these gases have?

Answer 14

They can trap I-R radiation and emits heat into the atmosphere. As a result the temperature of the atmosphere increases. This is called the greenhouse effect

Question 15

What is the bad effect of SO2

Answer 15

Produces acid rain when it reacts with H2O and O2 which corrodes marble, stone and metals

Question 16

How is CO formed

Answer 16

When any carbon compound is burnt in insufficient supplies of O2 the I burned carbon which remains is called soot

Question 17

What happens if CO is inhaled?

Answer 17

It combines with haemoglobin in the blood and forms oxy-haemoglobin. If this compound is formed in the blood it prevents the supply of oxygen as a result dizziness, suffocation, passing out and death

Question 18

What are acidic gases

Answer 18

SO2
Cl2
CO2
F2

Question 19

Alkaline gases

Answer 19

NH3

Question 20

Unreactive gases

Answer 20

Ar
N2

Question 21

Toxic gases

Answer 21

CO

Question 22

Greenhouse gases

Answer 22

CO2
CH4
SO2

Question 23

Neutral gases

Answer 23

O2
H2
CO
Ar
N2
CH4

Question 24

78% in air

Answer 24

N2

Question 25

Explosive gas

Answer 25

H2

Question 26

Pale yellow

Answer 26

F2

Question 27

Active part of air

Answer 27

O2