2020 Paper

Question 1

What colour are copper ions

Answer 1

Blue

Question 2

Describe reaction for copper, magnesium and iron with hydrochloric acid

Answer 2

Copper - no reaction so no temp change and no bubbles form
Magnesium - magnesium forms bubbles faster than iron and has a bigger increase in temperature than iron

Question 3

Why does copper not react with hydrochloric acid

Answer 3

Copper is below hydrogen in reactivity series so it can’t displace hydrogen
Less than hydrogen:
Copper
Silver
Gold

Question 4

Ionic equation for magnesium and zinc

Answer 4

Mg (s) + Zn 2+ (aq) —> Mg 2+ (aq) + Zn (s)

Question 5

Give the 2 fuel cell equations

Answer 5

H2 —> 2H+ + 2e-
O2 + 4H+ + 4e- —> 2H20

Question 6

What is needed in a boiling point

Answer 6

More than 1 molecule as it relates to intermolecular forces and boiling point is a bulk property

Question 7

Describe energy changes graph

Answer 7

Temperature initially decreases as reaction is endothermic and energy is taken in by the reaction from the solution. Mass continues to be added in excess. The temperature then increases as energy is transferred from the surroundings to solution