Chapter 10b Water: Specific Heat Capacity and Latent Heat

Water has a high specific heat capacity because

• it is a covalent molecular substance.

• it has a large amount of hydrogen bonding between all molecules.

• it has a relatively high density.

• it covers most of the earth's surface and therefore absorbs a lot of heat.

The amount of energy required to raise the temperature of 50 g of water by 35 °C is

• 7.315 kJ

• 418.7 J

• 89.18 J

• 1.754 kJ

The increase in temperature of 120 g of ethanol caused by applying 3 kJ of heat energy is

• 10 °C

• 0.01 °C

• 62.5 °C

• 100 °C

The mass of water that has increased in temperature by 20 °C when 5 kJ of energy has been used to heat it is

• 59.8 g

• 23.9 kg

• 1.05 kg

• 78.6 g

The energy required to change water from a solid to a liquid is called

• the latent heat of freezing.

• the latent heat of fusion.

• the latent heat of melting.

• the latent heat of liquification.

The energy required to change water from a liquid to a gas is called

• the latent heat of vaporisation.

• the latent heat of condensation.

• the latent heat of gasification.

• the latent heat of deliquification.

Calculate, using the equation q = nL, the amount of energy required to vaporise 3 mol of H₂O.

Lv = 40.7 kJ mol^-1

• 122.1 kJ

• 43.7 kJ

• 13.6 kJ

• 37.7 kJ

Calculate the amount of energy required to vaporise an ice cube that weighs 10 g.

c = 4.18 J g^-1 °C^-1, Lf = 40.7 kJ mol^-1 & Lv = 40.7 kJ mol^-1

• 30.1 kJ

• 25.9 kJ

• 4.2 kJ

• 26.8 kJ