Gases in the atmosphere

Question 1

What is the percentage of nitrogen in the air?

Answer 1

78.1%

Question 2

What is the percentage of oxygen in the air?

Answer 2

21.0%

Question 3

What is the percentage of argon in the air?

Answer 3

0.9%

Question 4

What is the percentage of carbon dioxide in the air?

Answer 4

0.04%

Question 5

How do you determine the percentage of oxygen in the air using an experiment with copper?

Answer 5

Pass air back and forth over heated copper till at constant volume

Question 6

How do you determine the percentage of oxygen in the air using an experiment with phosphorus?

Answer 6

Phosphorus is ignited and burns in air to form solid phosphorus oxide which dissolves in water changing the pressure

Question 7

How do you determine the percentage of oxygen in the air using an experiment with iron fillings?

Answer 7

The iron fillings rust reducing the volume of air and changing the pressure

Question 8

What is observed in the combustion of magnesium and oxygen?

Answer 8

Bright white flame

Question 9

What is observed in the combustion of hydrogen and oxygen?

Answer 9

Blue flame

Question 10

What is observed in the combustion of sulphur and oxygen?

Answer 10

Bright blue flame

Question 11

What is the equation for the combustion of magnesium and oxygen?

Answer 11

2Mg(s) + O₂(g) -> 2MgO(s)

Question 12

What is the equation for the combustion of hydrogen and oxygen?

Answer 12

2H₂(g) + O₂(g) -> 2H₂O(l)

Question 13

What is the equation for the combustion of sulphur and oxygen?

Answer 13

S(s) + O₂(g) -> SO₂(g)

Question 14

What are the products for the combustion of magnesium and oxygen?

Answer 14

Basic, white magnesium oxide powder which is slightly soluble in water

Question 15

What are the products for the combustion of sulphur and oxygen?

Answer 15

Sulphur dioxide is an acidic oxide and dissolves in water to produce sulphurous acid solution