Calculate the enthalpy change on freezing of 1 0 mol of water at 10 0 C to ice at - Chemistry - Thermodynamics

Question

Calculate the enthalpy change on freezing of 1 0 mol of
water at 10 0°C to ice at –10 0°C
Δ fus
H = 6 03 kJ mol
–1 at 0°C
C p
[H 2 O(l)] = 75 3 J
mol –1 K
–1
C p
[H 2 O(s)] = 36 8 J
mol –1 K
–1

Prerna Bansal · Accepted Answer

Total enthalpy change involved in the transformation is the sum
of the following changes:
(a) Energy change involved in the transformation of 1 mol of
water at 10°C to 1 mol of water at 0°C
(b) Energy change involved in the transformation of 1 mol of
water at 0° to 1 mol of ice at 0°C
(c) Energy change involved in the transformation of 1 mol of ice
at 0°C to 1 mol of ice at –10°C
<img src=
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= (75 3 J mol–1 K–1) (0
– 10)K + (–6 03 × 103 J
mol–1) + (36 8 J mol–1
K–1) (–10 – 0)K
= –753 J mol–1
– 6030 J mol–1
– 368 J mol–1
= –7151 J
mol–1
= –7 151 kJ
mol–1
Hence, the enthalpy change involved in the
transformation is –7 151 kJ
mol–1

Calculate the enthalpy change on freezing of 1.0 mol of water at 10.0°C to ice at –10.0°C. Δ fus H = 6.03 kJ mol –1 at 0°C. C p [H 2 O(l)] = 75.3 J mol –1 K –1 C p [H 2 O(s)] = 36.8 J mol –1 K –1

Calculate the enthalpy change on freezing of 1.0 mol of water at 10.0°C to ice at –10.0°C. Δ _fus H = 6.03 kJ mol ^–1 at 0°C.

C _p [H ₂ O(l)] = 75.3 J mol ^–1 K ^–1

C _p [H ₂ O(s)] = 36.8 J mol ^–1 K ^–1