Question

how much ice at -10degree celsius is needed to cool .1 kg of ethyl alcohol and .1kg of water from 20 degree celcius to 5 degree celsius?

Answer 1

The amount of ice needed to cool .1 kg of ethyl alcohol and .1 kg of water from 20 degree Celsius to 5 degree Celsius is approximately 0.2 kg. This is because the specific heat capacity of ethyl alcohol is 2.44 kJ/kgK and the specific heat capacity of water is 4.18 kJ/kgK. Therefore, the total amount of energy needed to cool the two substances from 20 degree Celsius to 5 degree Celsius is (2.44 x 0.1 x 15) + (4.18 x 0.1 x 15) = 4.62 kJ. Since the latent heat of fusion of ice is 334 kJ/kg, the amount of ice needed to cool the two substances is 4.62/334 = 0.0138 kg, which is approximately 0.2 kg.