2.c - Gasses in the atmosphere

Question 1

method of collecting carbon dioxide

Answer 1

thermal decomposition copper carbonate (green powder)

copper carbonate = carbon dioxide + copper oxide

heat copper (II) carbonate and collect the gas ( CO2) given off in a test tube.

Question 2

what does thermal decomposition of metal carbonates produce

Answer 2

Carbon dioxide + metal oxide

Question 3

how can you produce carbon dioxide and metal oxides

Answer 3

from metal carbonates

Question 4

what are the properties of carbon dioxide

Answer 4

denser than air

slightly soluble in water

Question 5

why is carbon dioxide being denser than air make it a suitable use for

Answer 5

fire extinguishers

denser than air = sinks = can smother a fire = starve fire of oxygen = put the fire out

Question 6

What is the percentage of the four most abundant gases in air

Answer 6

Nitrogen = 78%

Oxygen = 21%

Carbon Dioxide = 0.04%

Argon= nearly 1%

Question 7

How can iron be used to determine the percentage of oxygen in air

Answer 7

Iron removes oxygen from air to form rust

1. Push Iron wool in acetic acid ( catalyst) into measuring cylinder then invert measuring cylinder into beaker of water
2. Record starting position of water = starting volume of air using scale on MEASURING CYLINDER
3. Over time level of water in measuring cylinder rises
4. Iron reacts with oxygen = iron oxide, water rises = fill space oxygen took up
5. Leave measuring cylinder for about a week or until water level stops changing
6. Record finishing position of water = final volume of air

Question 8

How to calculate the % of oxygen from iron and phosphorus volume experiments

Answer 8

( Start volume - final volume / start volume ) x 100

Question 9

How can phosphorus be used to determine the % of oxygen in air

Answer 9

1. Place phosphorus in tube and attach glass syringe at each end, 1 filled with air and 1 empty
2. Heat phosphorus + use syringe to pass air over it - phosphorus + oxygen = phosphorus oxide
3. As it reacts amount of air in syringes decreases
4. Measure starting and final volume of air using scale on one of the syringes ( push all air into one syringe to measure final volume )

Question 10

Describe the combustion of magnesium in oxygen

Answer 10

Bright white flame
Forms white powder = magnesium oxide

( MgO = slightly alkaline when dissolved in water )

Question 11

Describe the combustion of hydrogen in air

Answer 11

Burns very easily = explosive = small amounts = squeaky pop

Orange/ yellow flame

Forms water ( as water vapour )

Question 12

Describe combustion of Sulfur in oxygen

Answer 12

Pale blue flame

Produce Sulfur dioxide

Sulfur dioxide = acidic when dissolved in water

Question 13

What is carbon dioxide

Answer 13

A green house gas

Question 14

What do greenhouse gasses do

Answer 14

Act like insulating layer

Absorb most of the heat that would normally be radiated our into space, and re-radiate in all directions including back towards earth

Question 15

What kind of human activity effects the amount of carbon dioxide in the atmosphere

Answer 15

Deforestation = less CO2 removed via photosynthesis

Burning fossil fuels

Both increase amount of CO2

Question 16

How does the increasing amount of CO2 in the atmosphere linked to (effect) climate change

Answer 16

Increase in CO2 = increase average temp of Earth = ( correlation ) = global warming

Question 17

What is global warming

Answer 17

Type of climate change + causes other type of climate change.

Eg. Changing rainfall patterns
Cause severe flooding due to polar ice caps melting and sea level rising