The combustion of 0.1625 g benzoic acid increases the temperature of a bomb calorimeter by 2.41°c. calculate the heat capacity of this calorimeter. (the energy released by combustion of benzoic acid is 26.42 kj/g.)
kj/°c
a 0.2070 g sample of vanillin (c8h8o3) is then burned in the same calorimeter, and the temperature increases by 3.19°c. what is the energy of combustion per gram of vanillin?
kj/g
what is the energy of combustion per mole of vanillin?
kj/mol

Answer :

The specific heat of calorimeter is

The energy of combustion per mole of vanillin is

Explanation :

Part 1 :

First we have to calculate the energy released for 0.1625 g of benzoic acid.

Energy released = Energy released × Mass of benzoic acid

Energy released = (26.42 kJ/g) × (0.1625g)

Energy released = -4.293 kJ

Now we have to calculate the specific heat of calorimeter.

Heat released by the reaction = Heat absorbed by the calorimeter

where,

= heat released by the reaction = -4.293 kJ

= heat absorbed by the calorimeter

= specific heat of calorimeter = ?

= change in temperature =

Now put all the given values in the above formula, we get:

Thus, the specific heat of calorimeter is

Part 2 :

First we have to calculate the energy released by the reaction.

where,

= heat released by the reaction = ?

= heat absorbed by the calorimeter

= specific heat of calorimeter =

= change in temperature =

Now put all the given values in the above formula, we get:

Now we have to calculate the energy of combustion per mole of vanillin.

Molar mass of vanillin = 152.15 g/mole

Mass of vanillin = 0.2070 g

Thus, the energy of combustion per mole of vanillin is