C9 Evolution Of The Atmosphere

Question 1

What is carbon footprint

Answer 1

Carbon footprints are a measure of the amount of carbon dioxide and other greenhouse gases released over the full cycle of something

Question 2

What is produced during incomplete combustion

Answer 2

Solid particles of carbon
Carbon monoxide

Question 3

What is produced during during complete combustion

Answer 3

Carbon dioxide and water vapour

Question 4

Why is solid particles of carbon bad for you

Answer 4

They can get stuck in your lungs and cause damage.Lead to respiratory problems

Question 5

What is potable water

Answer 5

Water that is safe for humans to drink

Question 6

Fresh water contains low levels of dissolved substances.So filtration and sterilisation is needed.What are they

Answer 6

Filtration - water is passed through a wire mesh.This stops large things like twigs from passing through.Next filter beds are used to filter out any other solid bits.

Sterilisation - the water is sterilised .Means that any harmful bacteria or microbes in the water are killed.This can be done by bubbling chlorine gas through it or by using ultraviolet light or ozone

Question 7

Practical of desalination

Answer 7

Heat water in flask using bunsen burner
As the water heats up it evaporates and becomes a gas.Gas enters the condenser as steam.Cold water is pumped around the condenser to cool the stream inside of it .This drop in temperature makes the steam condense back and into liquid water,
Collect water running out of condenser into a beaker.
Retest the ph of the water with a Ph meter to check its neutral
After water has been distilled see whether there are any crystals in the round bottomed flask.If there are crystals .It means there were salts in the water

Question 8

Cloudy precipitate measuring rates of reaction practical

Answer 8

Start by adding set volume ofndilute sodium thinosulfate
Place flask on a piece ofnpaper with a black cross drawn on it
Add some dilute hydrochloric acid toto the flask and start the stopwatch.
Watch the black cross disappear theough the cloudy sulfur and see howmlong it takes.
Repeat the reaction using different concentrations of hydrochloric acid

Question 9

Measuring gas volume - measuring rates of reaction

Answer 9

Measure 50 cm cubed of sulfuric acid solution into a flask
Add magnesium ribbo to the flask and connect it to the gas collection equipment
Start stopwatch and record volume of gas every 10 seconds
Whwn reaction is complete , cadd more sulfuric acid