Question

A copper block of mass $2.5\text{kg}$ is heated in a furnance to a temperature of ${500}^{\circ }\text{C}$ and then placed on a large ice block of temperature $0^{\circ }\text{C}$. The maximum amount of ice that can melt is:
(Specific heat of copper$=0.39\text{J}{\text{g}}^{-1\circ }{\text{C}}^{-1}$, latent heat of fusion of ice $=334{\text{Jg}}^{-1}$ )

• A. $1.6\text{kg}$
• B. $1.8\text{kg}$
• C. $1.46\text{kg}$
• D. $1.25\text{kg}$

Answer 1

The correct option is C $1.46\text{kg}$

Given:
Mass of copper block $=2.5\text{kg}$
Temperature of the block$={500}^{\circ }\text{C}$
Specific heat of copper$=0.39\text{J}{\text{g}}^{-1\circ }{\text{C}}^{-1}$
Latent heat of fusion of ice $=334{\text{Jg}}^{-1}$

As the amount of ice is large all the heat energy of the copper block will be used to melt the ice until the temperature of the block becomes $0^{\circ }\text{C}$.
Hence,
Heat realesead by block = Mass of ice melt $\times$ Latent heat of fusion of ice
$\Rightarrow m_{copper}{s}_{copper}\Delta T=m_{ice}{L}_{ice}$
$\Rightarrow 2.5\times {10}^3\times 0.39\times 500=m_{ice}\times 334$
$\Rightarrow m_{ice}=1460\text{g}=1.46\text{kg}$