C11 Air and Water

Question 1

Describe the chemical test for water using cobalt (ll) chloride

Answer 1

Blue anhydrous cobalt chloride turns pink in the presence of water

Question 2

Describe the chemical test for water using copper sulfate

Answer 2

White anhydrous copper sulfate turns blue in the presence of water

Question 3

What does potable mean

Answer 3

Safe to drink

Question 4

What two main stages are required to make water potable?

Answer 4

Filtration: removes insoluble particles by passing the water through layers of sand and filter

Chlorination: kills bacteria and microorganisms which are too small to be removed by filtration

Question 5

How is water used in home

Answer 5

Drinking cooking plumbing heating dishwasher

Question 6

How is water used in industry

Answer 6

Solvent, coolant, cleaning

Question 7

Composition of gases in the atmosphere

Answer 7

78% nitrogen
21% oxygen
0.93% argon
0.04% co2

Question 8

Common pollutants in air

Answer 8

Carbon monoxide
Sulfur dioxide
Oxides of njtrogen
Lead compounds

Question 9

Sources of pollutants

Answer 9

Carbon monoxide: incomplete combustion of carbon containing compounds.
Sulfur dioxide: combustion of fossil fuels which contain sulfur
Oxides of nitrogen: car engines
Lead engines: leaded petrol

Question 10

What is catalytic converter?

Answer 10

They are fitted in cars to remove oxides of nitrogen. They catalyse reaction between carbon monoxide and nitrogen monoxide, forming nirogen and co2

Question 11

Word equation of the reaction that takes place in a catalytic converter

Answer 11

Carbon monoxide+nitogen monoxide>carbon dioxide+nitrogen

Question 12

What are the problems associated with carbon monoxide

Answer 12

Its a toxic gas.
Odorless and colorless and uf breathed in it can cause DEATH by preventing the rbc from carrying oxygen around the body

Question 13

Problems associated with sulfur dioxide

Answer 13

It combines with water vapour in the clouds to form acid rain. Acid rain causes the following problems:

-corrodes limestone buildings and statues
-lowers pH of large bodies of water, killing the wildlife
-damages and kills vegetation

Question 14

Problems associated with oxides of nitrogen

Answer 14

-produces acid rain with simialr effect as So2
-reacts with other pollutants to form a smog which causes respiratory problems

Question 15

Why is pollution a global concern?

Answer 15

Fossil fuels are used globally and so these pollutants are largely found all over the world. Pollution enters the atmosphere where it affects all countries, not just those that use fossil fuels heavily

Question 16

What is rusting

Answer 16

Name specifically given to the corrosion of iron where it reacts to oxygen and water in the air

Question 17

Which two substances need to be excluded to prevent rusting

Answer 17

Oxygen and water

Question 18

How can oxygen and water be excluded to prevent iron rusting

Answer 18

-paint the metal
-coat the metal in oil
-cover metal in plastic
-keep the metal in vaccum container

Question 19

What is sacrificial protection? How does it prevent corrosion?

Answer 19

Sacrificial protection involves coating the metal being protected with a more reactive metal. The outer metal will corrode first and will prevnt it

Question 20

Link the reactivity series to the metals used in sacrificial protection

Answer 20

The metal used for protection must be higher up the reactivity series than the other metal so that it is more reactive. This means it will corrode first.

Question 21

What is galvanization

Answer 21

The sacrificial protection of iron using zinc

Question 22

Compounds of which three elements wre commonly found in fertilisers

Answer 22

Nitrogen, phosphorus and potassium cuz it improves agricultural production. They’re absorbed by plants roots to help growth and development

Question 23

How can ammonia be produced from an ammonium salt byva displacement reaction

Answer 23

When ammonium salt is reacted with a strong base, ammonia us produced along with water and a differeng salt

Question 24

Harber process

Answer 24

An industrial process used ro produce ammonia for fertilisers

Question 25

Conditions required for the haber process

Answer 25

450c temp
200 atm pressure
Iron catalyst

Question 26

What are greenhouse gases? 2 common examples

Answer 26

Greenshouse gases are responsible for maintaining the Earths temperature so that life can survive

Examples: co2, methane, water vapour

Question 27

How do greenhouse gases contribute to climate change?

Answer 27

Electromagnetic radiation ftom the sun passes thru the atmosphere. Radiation is absorbed by earth so that the temp increases. Heat is radiated from the earth as infrared radiation which is absorbed by greenhouses gases in the atmosphere cuasing the temp to warm up

Question 28

Global effects of climate change

Answer 28

Rising sea levels
Crops unable to grow
Extinction of species
Extreme weather
Risk of skin cancer

Question 29

Different ways co2 is produced

Answer 29

Complete combustion if co2 containing conpounds
Thermal decomposition of carbonates
Reaction between acid and a carbonate
Product of respiration

Question 30

Sources od methane gas

Answer 30

Combistion of fossil fuels
Decomposition of vegetation
Waste gas from digestion in livestock