Chapter 24, Problem 101A

Interpretation Introduction

Interpretation:

Heat evolved by reaction in calorimeter is to be estimated.

Concept introduction:

Calorimeter is a device that is employed to measure the heat absorbed or released by the system. Calorimeter is of two types:

1. Coffee cup calorimeter

2. Bomb calorimeter

Quantity of heat exchanged in an experiment is dependent on 3factors- amount of materials, the heat exchanging capacity expressed as specific heat and the temperature change the material undergoes. The general relationship is as follows:

$\text{q}=\left(\text{mass}\right)\left(\text{c}\right)\left({\text{T}}_2-{\text{T}}_1\right)$

There,

${\text{T}}_2$ is final temperature.

${\text{T}}_1$ is initial temperature.

$\text{q}$ is heat released or absorbed.

$\text{c}$ is specific heat capacity of the substance.

Answer to Problem 101A

Heat evolved by reaction in calorimeter is $45548.697\text{J}$ when temperature of $756\text{g}$ of water in calorimeter increases from $\text{23}\text{.2}{}^{\text{ο}}\text{C}$ to $37.6°\text{C}$.

Explanation of Solution

The formula to calculate reaction in calorimeter is a follows:

$\text{q}=\left(\text{mass}\right)\left(\text{c}\right)\left({\text{T}}_2-{\text{T}}_1\right)$

There,

${\text{T}}_2$ is final temperature.

${\text{T}}_1$ is initial temperature.

$\text{q}$ is heat released or absorbed.

$\text{c}$ is specific heat capacity of the substance.

Substitute $756\text{g}$ for mass, $\text{4}\text{.184}\text{J/}\left(\text{g}{\text{.}}^{\text{ο}}\text{C}\right)$ for $\text{c}$, $37.6°\text{C}$ for ${\text{T}}_2$ and $\text{23}\text{.2}{}^{\text{ο}}\text{C}$ for ${\text{T}}_1$ in above equation.

$\begin{array}{c}\text{q}=\left(\text{mass}\right)\left(\text{c}\right)\left({\text{T}}_2-{\text{T}}_1\right)\\ =\left(756\text{g}\right)\left(\text{4}\text{.184}\text{J/}\left(\text{g}{\text{.}}^{\text{ο}}\text{C}\right)\right)\left(37.6°\text{C}-\text{23}\text{.2}{}^{\text{ο}}\text{C}\right)\\ =45548.697\text{J}\end{array}$

Heat evolved by reaction in calorimeter is $45548.697\text{J}$ when temperature of $756\text{g}$ of water in calorimeter increases from $\text{23}\text{.2}{}^{\text{ο}}\text{C}$ to $37.6°\text{C}$.

Conclusion

Heat evolved by reaction in calorimeter is $45548.697\text{J}$ when temperature of $756\text{g}$ of water in calorimeter increases from $\text{23}\text{.2}{}^{\text{ο}}\text{C}$ to $37.6°\text{C}$.