Chapter 3, Problem 3.81AQAP

Interpretation Introduction

(a)

Interpretation:

The heat energy lost when 15.0 g of water is cooled from $60.5\text{C}$ to $-42.0\text{C}$ should be calculated.

Concept Introduction:

• Specific heat is the amount of heat in joules required to raise the temperature of 1 gram of a substance by $1\text{C}$ . It is expressed in terms of $\text{J/g}\text{C}$
• The amount of heat absorbed or evolved as the temperature changes from T₁ to T₂ is given as:

  $\begin{array}{l}{\text{Q = mcΔT = mc(T}}_{\text{2}}{\text{-T}}_{\text{1}}\text{) -----(1)}\\ \text{m = mass of the substance}\\ \text{c = specific heat}\end{array}$

Interpretation Introduction

(b)

Interpretation:

The heat energy lost when 125 g of iron is cooled from $118\text{C}$ to $55.0\text{C}$ should be calculated.

Concept Introduction:

• Specific heat is the amount of heat in joules required to raise the temperature of 1 gram of a substance by $1\text{C}$ . It is expressed in terms of $\text{J/g}\text{C}$
• The amount of heat absorbed or evolved as the temperature changes from T₁ to T₂ is given as:

  $\begin{array}{l}{\text{Q = mcΔT = mc(T}}_{\text{2}}{\text{-T}}_{\text{1}}\text{) -----(1)}\\ \text{m = mass of the substance}\\ \text{c = specific heat}\end{array}$