Question

A block of ice of mass 120 g at temperature 0°C is put in 300 gm of water at 25°C. The xg of ice melts as the temperature of the water reaches 0°C. The value of x is ______.

[Use: Specific heat capacity of water = 4200 Jkg^-1K^-1, Latent heat of ice = 3.5 × 10⁵ Jkg^-1]

Options

• 40

• 50

• 60

• 90

Answer 1

A block of ice of mass 120 g at temperature 0°C is put in 300 gm of water at 25°C. The xg of ice melts as the temperature of the water reaches 0°C. The value of x is 90.

Explanation:

The energy released by water = MΔTS

= 0.3 × 25 × 4200 = 31500J

Let m kg ice melts = mL

m × 3.5 × 10⁵ = 31500 [∵ Heat lost = Heat absorbed]

⇒ m = `(31500 xx 10^-5)/3.5 = 9000 xx 10^-5`

m = 0.09 kg = 90 gm ⇒ x = 90