Question

When 1.0 g of a snack cake is combusted in a constant-pressure bomb calorimeter with a heat capacity (including its water) of 10.0 kJ/°C, the temperature of the calorimeter rises by 2.24°C. How many nutritional calories (Calories) are in one serving (28 g) of this snack cake? (1 Calorie = 1000 calories and 1 calorie = 4.184 J)

Answer 1

Answer on Question #77999, Chemistry / General Chemistry

When 1.0 g of a snack cake is combusted in a constant-pressure bomb calorimeter with a heat capacity (including its water) of 10.0 kJ/°C, the temperature of the calorimeter rises by 2.24°C. How many nutritional calories (Calories) are in one serving (28 g) of this snack cake? (1 Calorie = 1000 calories and 1 calorie = 4.184 J)

Solution

$Q = c \times m \times \Delta T$, where $c$ – specific heat, $Q$ – heat released.

$Q = 10 \times 1 \times 2.24 = 22.4\ (\mathrm{kJ})$ – heat released from the combustion of 1 g.

$Q_{\text{tot}} = 22.4 \times 28 = 627.2\ (\mathrm{kJ})$

$Q_{\text{cal}} = \frac{627200}{4.184} = 149904\ (\mathrm{cal}) = 149.9\ (\mathrm{cal})$

Answer

149.9 Calories are in one serving cake.