State the meaning of specific latent heat.
A student measures the specific latent heat of vaporisation of a liquid using the apparatus shown in Fig. 3.1. The heater is turned on. Once the liquid is boiling at a steady rate, the balance reading is recorded at $2.0$ minute intervals. After $10$ minutes, the current in the heater is reduced and the balance readings are continued for another $12$ minutes.
Between time $0$ and time $10.0$ minutes, the mass of liquid evaporated is $56\,\text{g}$. Use Fig. 3.3 to find the mass of liquid evaporated from time $12.0$ minutes to time $22.0$ minutes.
Explain why, although the heater power is changed, the rate at which thermal energy is lost to the surroundings may be taken to remain constant.
Determine a value for the specific latent heat of vaporisation $L$ of the liquid.
Calculate the rate at which thermal energy is transferred to the surroundings.