Chapter 14, Problem 14.88P

Interpretation Introduction

Interpretation:

The amount of nutritional calories present in per gram of candy has to be determined.

Concept Introduction:

Enthalpy of reaction can be used to find heat capacity $\left(c_{\text{P}}\right)$. Heat capacity is the value of energy for particular substance that is required to raise substance’s temperature by $1°\text{C}$ or $1\text{K}$. The expression to calculate heat capacity is as follows:

  $c_{\text{P}}=\frac{q_{\text{P}}}{\Delta T}$

Here, $q_{\text{P}}$ input of energy at constant pressure, $\Delta T$ is increase in temperature after input of energy.

The value heat capacity of unit mole substance is known as molar heat capacity and it is represented by $C_{\text{P}}$. The expression of molar heat capacity is as follows:

  $C_{\text{P}}=\frac{q_{\text{P}}}{n\Delta T}$

Here, $n$ is number of moles.

Also, The value heat capacity per gram is known as specific heat capacity and it is represented by $c_{\text{sp}}$. The expression of molar heat capacity is as follows:

  $c_{\text{sp}}=\frac{q_{\text{P}}}{m\Delta T}$

Here, $m$ is mass in grams.

In bomb calorimeter, the expression of energy change in the reaction is written as follows:

  $\Delta H=-c_{\text{V,cal}}\Delta T$