Question

At 1 atm, how much energy is required to heat 85.0 g of H2O(s) at –16.0 °C to H2O(g) at 117.0 °C?

Answer 1

Specific heat capacity, ice: 2.03 J/g ⁰C

Specific heat capacity, water: 4.18 J/g ⁰C

Specific heat capacity, water vapor: 1.01 J/g ⁰C

Heat of fusion of water: 334 J/g

Heat of vaporization of water: 2260 J/g

There are two phase changes occurring. Water in its different phases has a different heat capacity. Then the phase changes take energy as well.

(85 g ice)(16 °C)(2.03 J/g ⁰C) + (85 g ice)(334 J/g) + (85 g water)(100 °C)(4.18 J/g ⁰C) + (85 g water)(2260 J/g) + (85 g steam)(17 °c)(1.01 J/g ⁰C)

= 260.2 KJ