Question

At constant volume, the heat of combustion of a particular compound is −3300.0 kJ/mol. When 1.327 g of this compound (molar mass=189.80 g/mol) was burned in a bomb calorimeter, the temperature of the calorimeter, including its contents, rose by 3.747 ∘C. What is the heat capacity (calorimeter constant) of the calorimeter?

Answer 1

Ans :- 6.156 KJ/^∘C

Explanation :-

Given,

Heat of combustion = −3300.0 kJ/mol

-ve sign shows that heat releases.

Change in temperature = 3.747 ^∘C

Mass of compound = 1.327 g

Because, Number of moles = Given mass / Gram molar mmass

Therefore,

No. Moles of compound = Given Mass/molar mass = 1.327 g /189.80 g/mol = 6.99 x 10^-3 mol

Now,

Amount of heat released in reaction = No. of Moles of compound x Heat of combustion

= −3300.0 kJ/mol x 6.99 x 10^-3 mol

= - 23.067 KJ

Now,

Heat capacity of calorimeter (calorimeter constant) = Amount of heat released in reaction / Change in temperature

= 23.067 KJ / 3.747 ^∘C

= 6.156 KJ/^∘C

Therefore ,

Heat capacity (calorimeter constant) of the calorimeter = 6.156 KJ/^∘C