First slide

Questions based on phase change

Question

Steam at 100⁰C is passed into 20 g of water at 10⁰C. When water acquires a temperature of 80⁰C, the mass of water present will be (Take, specific heat of water = 1 calg^-1 ⁰C^-1 and latent heat of steam = 540 cal g^-1)

Moderate

A

24 g
B

31.5 g
C

42.5 g
D

22.5 g

Solution

Heat lost by system = Heat gained by water
Let $m'$ be amount of heat converted into water
$m' \times L = m c Δ t$
$m' \times 540 = 20 \times 1 \times (80 - 10)$
$\Rightarrow m' = \frac{20 \times 70}{540} = 2.5 g$
Now, net mass of water = 20 + 2.5 = 22.5 g

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App