Question

When 1.23g of ethanol (delta c Hm = -1368kj/mol at 25 C ) is burned in an adiabatic flame calorimeter, the temperature increases by 8.6 C. Under the same experimental conditions, when 1.14g of 1-propanol is burned, the temperature increases by 9.0 C. What is delta c Hm for 1-propanol? Molar masses of ethanol and 1-propanol are 46.1 and 60.1g/mol, respectively.

Answer 1

figure the moles of each:
ethanon-1.23/46.1
prpanol-1.14/60.1

now the solution.

the temp rise is due to heat, which is Hm*molesburned

8.6/9.0=(-1366*molesethanol)/Hm*moleprpanol


calculate Hmpropaanol.

Hmprpanol=-1366*9.0/8.6*molesethanol/molespropanol