Gases in the air

Question 1

What are the 4 main gases in the air?

Answer 1

Nitrogen
Oxygen
Carbon Dioxide.
Argon.

Question 2

What is the rough percentage for Nitrogen?

Answer 2

~79

Question 3

What is the rough percentage for Oxygen?

Answer 3

~21

Question 4

What is the rough percentage for Carbon Dioxide?

Answer 4

~0.04

Question 5

What is the rough percentage for Argon?

Answer 5

<1%

Question 6

What is the purpose of Nitrogen?

Answer 6

Manufacturing of amonia of fertalizers.
Keeps things like crisps fresh.
Generally used in food packaging.

Question 7

What is the purpose of Oxygen?

Answer 7

Respiration

Question 8

What is the purpose of Carbon Dioxide?

Answer 8

Photosynthesis.
Carbonic Acid in fizzy drinks.
Carbon-dioxide in fire extinguishers.

Question 9

What is the purpose of Argon?

Answer 9

To replace oxygen in light bulbs to stop fires.

To create neon lights.

Question 10

Why do we end heated experiments early when working with measuirng gases? e.g. measuring oxygen in the air.

Answer 10

Because gases when heated expand and when cooled contract.

Question 11

How can you measure the oxygen in the air?

Answer 11

The percentage of oxygen in the air can be measured by passing a known volume of air over hot copper, and measuring the decrease in volume as the oxygen reacts with it. Here are the equations for this reaction:

copper + oxygen → copper oxide

Gas syringes are used to measure the volume of gas in the experiment.

Question 12

Describe the basic idea behind the oxygen in the air experiment?

Answer 12

Finding oxygen in air:
Two different amounts on each side.
Air passes from one side to another and the copper absorbs and reacts with the air. After the copper has been used the missing air is dispresence of oxygen.

Question 13

How could one tell that the oxygen in the air experiment had finished?

Answer 13

Because copper oxide would turn black as apposed to the copper metal before and no more oxygen or air could be absorbed.