Question

How much boiling water at 100°C is needed to melt 2 kg of ice so that the mixture which is all water is at 0°C?

Answer 1

[Specific heat capacity of water = 4.2 JKg^-1 and specific latent heat of ice = 336 Jg^-1]. 

Given, mass of ice = 2 kg = 2000 g. 

Let m be the mass of boiling water required. 

Heat lost = Heat gained. 

m × c × ∆t = m × L 

m × 4.2 × (100 – 0) = 2000 × 336

m = \(\frac{2000 \times 336}{4.2 \times 100}\)

= 1600 g or 1.6 kg.