Chapter 9, Problem 9.148MP

Interpretation Introduction

Interpretation:

The mass of each compound in the mixture of 10.0 g of ${\text{NaNO}}_{\text{3}}$ and $\text{KF}$ dissolve in 100.0 g of water that find the temperature rise by 2.22 °C should be determined.

$\begin{array}{l}{\text{NaNO}}_{\text{3(s)}}\stackrel{}{\to }{\text{NaNO}}_{\text{3(aq)}}\text{ ΔH = +20}\text{.4 kJ/mol}\\ {\text{KF}}_{\text{(s)}}\stackrel{}{\to }{\text{KF}}_{\text{(aq)}}\text{ ΔH = -17}\text{.7 kJ/mol}\end{array}$

Concept introduction:

The Gibb’s equation of thermodynamic purposed a relation between $\text{ΔS}$, $\text{ΔH}$ and $\text{ΔG}$ with temperature. With the help of this equation the change in $\text{ΔS}$, $\text{ΔH}$ and $\text{ΔG}$ can be predicted. For any reaction, the $\text{ΔH}$ and $\text{ΔS}$ can be calculated with the help of:

$\begin{array}{l}\text{ΔrS°= }\Sigma \text{ΔrS°product - }\sum \text{ΔrS°reactant}\\ \text{ΔrH°= }\Sigma \text{ΔrH°product - }\sum \text{ΔrH°reactant}\end{array}$

The change in temperature for the addition of two substances at two different temperatures can be calculated with the help of calorimetric equation:

$\begin{array}{l}\text{Q = m × C × ΔT}\\ \text{Here:}\\ \text{Q}\text{}\text{ = heat change }\\ \text{m = mass}\\ \text{C = specific heat }\\ \text{ΔT=change in T}\end{array}$