Question

A vessel of mass 80 g (S.H.C. = 0.8 Jg⁻¹°C⁻¹) contains 250 g of water at 35°C. Calculate the amount of ice at 0°C, which must be added to it, so that the final temperature is 5°C. [Sp. latent heat of ice = 340 Jg⁻¹]

Answer 1

Let the mass of ice be x g.

Heat gained by ice = 340x + x × 4.2 × 5

= 361x J

Heat lost by water = 250 × 4.2 × (35 − 5)

= 31500 J

Heat lost by vessel = 80 × 0.8 × (35 − 5)

= 1920 J

Total heat lost = 31500 + 1920 = 33420 J

Heat gained = Heat lost

361x = 33420

x = \[\frac{33420}{361}\]

x = 92.57 g