D.I.R.T

Question 1

Explain why carbon can be used to extract iron from iron oxide [2]

Answer 1

Carbon is more reactive than iron
Carbon displaces iron

Question 2

State one reason why it is better to use a 10cm3 measuring cylinder to measure the volume of water than a 25cm3 measuring cylinder [1]

Answer 2

Smaller error / lower uncertainty in reading

Question 3

If the activation energy of a reaction is increased what effect does this have on the number of effective collisions and the rate of reaction (think about the high jump analogy) [2]

Answer 3

Number of effective collision will be lower (if the bar is higher, less athletes get over it).
Rate of reaction will be lower