Question

Stearic acid $\left[C{H}_3\right(C{H}_2{)}_{16}C{O}_{2}H]$ is a fatty acid, the part of fat that stores most of the energy. $1.0g$ of stearic acid was burned in a bomb calorimeter. The bomb had a heat capacity of $652J{/}^{\circ }C$. If the temperature of $500g$ water $(c=4,18J/g^{\circ }C)$ rose from $25.0$ to ${39.3}^{\circ }C$, how much heat was released when the stearic acid was burned? [Given $C_P\left(H_{2}O\right)=4.18J/g^{\circ }C]$.

• A. $39.21kJ$
• B. $29.91kJ$
• C. $108kJ$
• D. $9.32kJ$

Answer 1

The correct option is A $39.21kJ$

As energy is conserved
Heat released = (heat capacity of bomb)$\ast \Delta T$ + $m_w{C}_p\Delta T$
$m_w$ is a mass of water in the bomb calorimeter
By taking values from the question $\Delta T$

$=14.3$
$H$ $=652\times 14.3+500\times 4.18\times 14.3$

$=39210.6J$
The heat released when the stearic acid was burned

$=39.21kJ$