Question

If the combustion of 0.158 g benzoic acid (C6H5CO2H) increase the temperature of a bomb calorimeter by 2.54°C, the heat capacity of the calorimeter is 1.65 kJ/°C, and 0.213 g sample of vanillin (C8H8O3) increase the temperature of the same calorimeter by 3.25°C.
Compare the molar energies of combustion for benzoic acid and vanillin

Answer 1

Answer:

Explanation:

when nothing is given to us

we assume it is at constant volume

so del u will be known to us

delu=cdelt/mole

delu=1.65*2.54 / 0.158/122

=3224

delh=delu+delngrt

delh=3224+0.5*0.008314*300.54

=3224+1.249

=3225.249

delu=cdelt/mole

=1.65*3.25/0.0014

=3830

delh = delu + delngrt

=3830-0.5*0.008314*301.25

=3830-1.25

=3828.747

molar energy of vanilliin is more than molar energy of benzoic acid