Chemical Reactions+ Chemistry of Gases

Question 1

What is the test for oxygen?

Answer 1

It will relight a glowing splint

Question 2

What is the test for hydrogen?

Answer 2

It burns with a pop

Question 3

What is the test for carbon dioxide?

Answer 3

Turns limewater cloudy

Question 4

What is the difference between normal air and breathed out air?

Answer 4

There is less oxygen in breathed out air.

Question 5

How do you calculate the % of oxygen in the air?

Answer 5

%oxygen in air= height water rose/ height of cylinder * 100

Question 6

What is the value of oxygen in the air?

Answer 6

21%

Question 7

How do you test for oxygen?

Answer 7

page 6 chemical reactions

Question 8

How do you test for hydrogen?

Answer 8

page 8 chemical reactions

Question 9

How do you test for carbon dioxide?

Answer 9

page 12 chemical reactions

Question 10

Why is helium good for airships?

Answer 10

-low density
-light
-not flammable
-less dense than air

Question 11

Name 4 types of energy.

Answer 11

-light
-heat
-sound
-kinetic

Question 12

What are the characteristics of a chemical reaction?

Answer 12

-colour change
-energy change
-solid is formed
-new substance is produced

Question 13

What is the concentration of salt in seawater in grams per litre?

Answer 13

20cm3 of salt was measured and weighed out and placed into an evaporating basin. The basin was then heated to evaporate the water. The basin was then re-weighed and the mass of salt calculated in 1L