0.5kg of water at 10ºC is completely converted to ice at 0ºC by extracting (88000) of heat from it. If the specific heat capacity of water is 4200jkg¹ Cº. Calculate the specific latent heat of the fusion of ice.

A. 9.0kjkg⁻¹
B. 84.0kjkg⁻¹
C. 134.0kjkg⁻¹
D. 168.0kjkg⁻¹

Correct Answer:

Option C = 134.0kjkg⁻¹

Explanation

Heat involved (H) = 88,000J, Mass(M)= 0.5kg, specific heat capacity of water(C) = 4200JkgºC,

Specific latent heat of fusion(L) = ?, Temperature change(Δθ) = θ2 – θ1 = (10 – 0)° = 10°

H = MCΔθ + ML

or

H = M(CΔθ + L) –>^H/_M = CΔθ + L

: L = ^H/_M – CΔθ = ^88,000/_0.5 – 4200 × 10

L = 176,000 – 42000 = 134,000

L = 134,000 or 134kj/kg