revise before mocks

Question 1

improvements for an enthalpy practical

Answer 1

• insulate beaker/use polystyrene cup —> reduces heat energy loss
• measure temp at regular intervals before adding metal —> established accurate initial temp
• plot graph of temp against time
• extrapolate the cooling back to the point of addition —> to establish max. theoretical temp

Question 2

explain how a catalyst has no effect on the % yield

Answer 2

increases rate of forwards & backwards reaction equally