Specific heat capacity and specific latent heatEdexcel International A Level Physics: Mind map

Exam questions on Specific heat capacity and specific latent heat

1. A student heats 0.50 kg of water in a well-insulated beaker using a 60 W immersion heater. The specific heat capacity of water is 4180 J kg⁻¹ K⁻¹. The heater is switched on for 520 s.
   The student measures a temperature rise of 12 K, not 15 K. Calculate the percentage of the electrical energy supplied that was transferred to the water.2 marks
2. A catering company uses ice to keep food chilled and steam to cook it. The specific latent heat of fusion of ice is 3.34 × 10⁵ J kg⁻¹ and the specific latent heat of vaporisation of water is 2.26 × 10⁶ J kg⁻¹. A cool box contains 0.30 kg of ice at 0 °C, which absorbs energy from the food at an average rate of 20 W.
   Calculate the energy released when 0.040 kg of steam at 100 °C condenses to water at 100 °C.2 marks
3. A student determines the specific latent heat of vaporisation of water. A beaker of water is placed in an insulated container on a top-pan balance, and a 12.0 V electric heater with an ammeter in series is lowered into the water. Once the water is boiling steadily, the student records the balance reading and switches the heater on for a measured time, then records the balance reading again.
   The ammeter reads 4.20 A and the heater is on for 300 s. The balance reading falls by 6.0 g. Calculate the specific latent heat of vaporisation of water from these results.3 marks