Calculate the amount of heat required to raise the temperature of a 24 g sample of water from 9°C to 23°C. Express your answer using two significant figures.

1400KJ/mol⁻¹

Explanation:

Amount of heat required can be found by:

Q = m × c × ΔT

Where m is the mass, c is the specific heat capacity (4.2KJ for water) and ΔT is the change in temperature.

Q = 24 × 4.2 × (23 - 9)

= 24 × 4.2 × 14

=   1411.2KJ/mol⁻¹

= 1400KJ/mol⁻¹  (to 2 significant figures)