Question

The molar heat of combustion of sucrose, C12H22O11, liberates 5650 kJ/mol of heat. A 100g calorimeter with a specific heat capacity of 17.5 J/g C contains 500g water. How many grams of sucrose would have to be burned to increase the temperature of the water and calorimeter by 4.5 C

Answer 1

Approximately 14.29 grams of sucrose would need to be burned to increase the temperature of the water and calorimeter by 4.5°C.

To calculate the amount of sucrose (C12H22O11) that needs to be burned to increase the temperature of the water and calorimeter by 4.5°C, we can use the heat transfer equation. The heat transferred (Q) is given by the product of mass (m), specific heat capacity (C), and temperature change (ΔT):

Q=m⋅C⋅ΔT

For this scenario, we consider the water and calorimeter as the system. The total mass (m) is the sum of the mass of water and the mass of the calorimeter:

m=m water​ +m calorimeter

Substituting in the given values, we calculate Q and set it equal to the molar heat of combustion (ΔH) of sucrose: Q=ΔH

m water​ ⋅C water​⋅ΔT+m calorimeter​⋅C calorimeter​⋅ΔT=n⋅ΔH

Solving for the moles of sucrose (n) and then converting it to grams using the molar mass of sucrose, we find that approximately 14.29 grams of sucrose would need to be burned to achieve the specified temperature increase.