Question

$0.08kg$of a substance is heated from$30°C$ to $130°C$, when$2000$ calories of energy is supplied to it. Calculate the specific heat capacity of the substance in (a) calories (b) joules.

Answer 1

Step 1: given data

mass$\left(m\right)=0.08kg$

heat absorbed$=2000calories$

Temperature changes from $30°C$to $130°C$

Specific heat capacity$\left(c\right)=?$

Step 2: (a)calculating the sp. heat capacity

Rise in temperature$\left({\theta }_R\right)=(130-30)°C=100°C$

Heat absorbed$=mc{\theta }_R$

$$\begin{gathered} \Rightarrow 200calories=0.08kg\times c\times 100°C \\ \Rightarrow c=\frac{2000}{0.08\times 100}=250calk{g}^{-1}°C^{-1} \end{gathered}$$

Step 3: (b)converting into joule

To convert calories into joule we need to multiply them by$4.2$,

Sp. heat capacity is the joule$$\begin{gathered} =250\times 4.2 \\ =1050Jk{g}^{-1}°C^{-1} \end{gathered}$$

The specific heat capacity of substance in calorie is$250calk{g}^{-1}°C^{-1}$ and in joule is$1050Jk{g}^{-1}°C^{-1}$.