Thermal physics

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445
Question 33
Medium

An industrial beaker is filled with 0.80 kg0.80\text{ kg}0.80 kg of liquid ethanol at an initial temperature of 18∘C18^\circ\text{C}18∘C. A 1.5 kW1.5\text{ kW}1.5 kW immersion heater is used to heat the ethanol for a time of 4.0 minutes4.0\text{ minutes}4.0 minutes.

a.

Calculate the total energy supplied by the heater during the time of 4.0 minutes4.0\text{ minutes}4.0 minutes.

[2]
b.

The specific heat capacity of liquid ethanol is 2400 J kg−1 K−12400\text{ J kg}^{-1}\text{ K}^{-1}2400 J kg−1 K−1 and its specific latent heat of vaporisation is 8.5×105 J kg−18.5 \times 10^5\text{ J kg}^{-1}8.5×105 J kg−1. The boiling point of ethanol is 78∘C78^\circ\text{C}78∘C.

Calculate the mass of ethanol remaining in the beaker after 4.0 minutes4.0\text{ minutes}4.0 minutes. Assume that all the thermal energy from the heater is transferred to the ethanol.

[4]

Thermal physics Questions

  1. A Level
  2. /Physics
  3. /Thermal physics