Question

The energy content of raisin bread is 13.1 kJ/g. Calculate the temperature increase when a slice of raisin bread (27.0 g) is burned in the calorimeter. The heat capacity of the calorimeter is

Answer 1

Complete question:

The energy content of raisin bread is 13.1 kJ/g. Calculate the temperature increase when a slice of raisin bread (27.0 g) is burned in the calorimeter. The heat capacity of the calorimeter is 36.7 kJ/°C

Answer:

9 °C

Explanation:

First, we determine the number of kJ in the slice bread by using the energy content of the bread to convert grams to kilojoules

q = energy content x weight of bread

q = 13.1 kJ/g x 27.0 g

q = 353.7 `kJ

Heat of the reaction = - 353.7 kJ (negative because heat is released)

$q_{rxn} = - q_{calorimeter}$

$q_{rxn} = - C_{calorimeter}$ * ΔT

where ΔT = temperature difference

-353.7 kJ = - 36.7 kJ/°C * ΔT

ΔT = -353.7 kJ

       -36.7 kJ/°C

ΔT = 9.6 °C

Therefore, the temperature increase is 9 °C