In a laboratory at normal room temperature, 150 g150\text{ g}150 g of water is poured into a beaker. A thermometer placed in the water has a reading of 24∘C24^\circ\text{C}24∘C.
Small pieces of ice at 0∘C0^\circ\text{C}0∘C are added to the water one by one. The mixture is stirred after each addition until the ice has melted. This process is continued until the temperature recorded by the thermometer is 0∘C0^\circ\text{C}0∘C.
The total mass of ice added to the water is found to be 45 g45\text{ g}45 g.
The specific heat capacity of water is 4.2 J/(g ∘C)4.2\text{ J}/(\text{g } ^\circ\text{C})4.2 J/(g ∘C).
Calculate the thermal energy lost by the water originally in the beaker.
Assume that all the thermal energy lost by the water originally in the beaker is transferred to the ice.
Calculate the specific latent heat of fusion of ice.
Suggest a reason for any inaccuracy in the value of the specific latent heat of fusion of ice calculated in (b). Assume the temperature readings and the values for the mass of the water and the mass of the ice are accurate.
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.