Question

Find the heat required to make water of $30{ }^{\circ} C$ from $10\, g$ of ice at $0.0{ }^{\circ} C$. (Enthalpy of fusion of ice $=333.55\, J\, g ^{-1}, \,C_{p}$ of water $=4.18\, Jg ^{-1} K ^{-1}$ )

• A. 4.0 kJ
• B. 5.0 kJ
• C. 3.59 kJ
• D. 4.59 kJ

Answer 1

Answer: (D)

Given, Initial temperature $=0^{\circ} \,C$

Final temperature $=30^{\circ}\, C$

Thus, $\Delta T=30^{\circ} \,C$

Mass of ice $(m)=10\, g$

Enthalpy of fusion $(L)=333.5\, Jg ^{-1}$

$C_{p}$ of water $=4.18 \,Jg ^{-1} \,K ^{-1}$

$\because$ Heat required $(Q)=m L+m C_{p} \Delta T$

$=10 \times 333.5+10 \times 4.18 \times 30$

$=3335.0+1254.00$

$=4589 \,J$

$=4.59\, kJ$