13 Jul 2026

Latent Heat of Fusion of Ice with Radiation Correction

practical ug-v thermal-physics latent-heat ice

Experimental arrangement

Method-of-mixtures arrangement showing the calorimeter, melting ice, thermometer, stirrer, and surrounding insulation.

Aim

To determine the latent heat of fusion of ice by the method of mixtures with radiation correction.

Apparatus

Calorimeter, ice, water, balance, thermometer, stirrer, and stopwatch.

Theory

Heat lost by warm water and calorimeter melts ice and raises the temperature of the melted ice. If $m_i$ is the mass of ice melted, $L$ is the latent heat, and $Q_r$ is the radiation correction,

\[Q_r+(m_wc_w+m_cc_c)(T_i-T_f)=m_iL+m_ic_wT_f.\]

Observations

Quantity	Value
Mass of water	$0.200\,\text{kg}$
Initial water temperature	$35.0^\circ\text{C}$
Final temperature	$8.0^\circ\text{C}$
Ice melted	$0.032\,\text{kg}$
Radiation correction	$0.18\,\text{kJ}$

Calculation

Using $c_w=4200\,\text{J kg}^{-1}\text{K}^{-1}$ and calorimeter water equivalent $0.020\,\text{kg}$,

\[L=3.31\times10^5\,\text{J kg}^{-1}.\]

Result

\[\boxed{L=3.31\times10^5\,\text{J kg}^{-1}}.\]

Precautions

1. Use dry ice pieces at $0^\circ\text{C}$.
2. Remove surface water before weighing the ice.
3. Transfer ice quickly and cover the calorimeter.
4. Apply the radiation correction from the cooling curve.

Viva Questions

1. Why must the ice be at zero degree? Otherwise part of the heat would first warm the ice.
2. What is latent heat? It is heat absorbed or released during a phase change without temperature change.
3. Why is surface water removed? It would add an error to the mass of melted ice.

Maxima Code

Download the Maxima calculation file.