Chapter 12, Problem 12.142P

a.

Interpretation Introduction

Interpretation:

The time to heat the sample to its melting point is to be calculated.

Concept introduction:

Specific heat capacity $\left(c\right)$ of a substance is the amount of heat needed to raise the temperature of $1\text{g}$ of a substance by $1\text{K}$. The formula to calculate heat required is as follows:

  $q=\left(\text{mass}\right)\left(c\right)\left(T_2-T_1\right)$        (1)

Here,

$T_2$ is the final temperature.

$T_1$ is the initial temperature.

$q$ is the heat released or absorbed.

$c$ is the specific heat capacity of the substance.

The formula to calculate heat at phase change is as follows:

  $q=\left(\text{mass}\right)\left(\Delta H\right)$        (2)

Here,

$\Delta H$ is the enthalpy change.

(b)

Interpretation Introduction

Interpretation:

The time taken to melt the sample is to be calculated.

Concept introduction:

Specific heat capacity $\left(c\right)$ of a substance is the amount of heat needed to raise the temperature of $1\text{g}$ of a substance by $1\text{K}$. The formula to calculate heat required is as follows:

  $q=\left(\text{mass}\right)\left(c\right)\left(T_2-T_1\right)$        (1)

Here,

$T_2$ is the final temperature.

$T_1$ is the initial temperature.

$q$ is the heat released or absorbed.

$c$ is the specific heat capacity of the substance.

The formula to calculate heat at phase change is as follows:

  $q=\left(\text{mass}\right)\left(\Delta H\right)$        (2)

Here,

$\Delta H$ is the enthalpy change.

(c)

Interpretation Introduction

Interpretation:

A curve of temperature vs. time for the entire heating process is to be calculated.

Concept introduction:

Specific heat capacity $\left(c\right)$ of a substance is the amount of heat needed to raise the temperature of $1\text{g}$ of a substance by $1\text{K}$. The formula to calculate heat required is as follows:

  $q=\left(\text{mass}\right)\left(c\right)\left(T_2-T_1\right)$        (1)

Here,

$T_2$ is the final temperature.

$T_1$ is the initial temperature.

$q$ is the heat released or absorbed.

$c$ is the specific heat capacity of the substance.

The formula to calculate heat at phase change is as follows:

  $q=\left(\text{mass}\right)\left(\Delta H\right)$        (2)

Here,

$\Delta H$ is the enthalpy change.