Calorimetry

Question 1

• Coffee cup calorimeter

Answer 1

○ Add one liquid to coffee cup, take temperature every minute until it stabilises (4 minutes)
○ Add second liquid to cup, measure temperature every minute from 6 minutes onward
○ Use graph to work out max ΔT during reaction (at 5 minutes)
○ Polystyrene is excellent insulator, minimizes heat loss to surroundings ○ Allows us to find accurate values for ΔH
○ Usually gives accurate results •

Question 2

Bomb calorimeter

Answer 2

○ Combusts sample in pure oxygen to burn as completely as possible
○ Minimises heat loss as much as possible
○ Measure mass of sample burned and temperature change of water

Question 3

Copper calorimeter and spirit burner

Answer 3

○ Useful for enthalpy of combustion of fuels
○ Heat given out by burning fuel is used to warm a mass of known water
○ Measure mass of fuel burned and the ΔT of water
○ Allows you to find approximate value for ΔH •