Steam at 100 ° C is passed into 1. 1kg of water contained in a...

(a) According to principle of calorimetry,
heat gained =~heat lost
Heat is lost by steam in two stages

(i) Change of state from steam at $100 ° C$ to water at $100 ° C$ is $m \times 540 .</p><p>(ii)$ To change water at100 ° C$to water at$80 ° C$is$m \times 1 \times \left(100 - 80\right)$,$~where $m$ is the mass of the steam condensed.

Total heat lost by steam is
$m \times 540 + m \times 20 = m \left(540 + 20\right)$ = 560m

Heat gained by calorimeter and $its contents is<br />\left(1 . 1 + 0 . 2\right)$ \times \left(80 - 15\right) = 1 . 12 \times 65\text{cal}$</p><p>$⇒ 560m = 1 . 12 \times 65$</p><p>$⇒ m = \dfrac{1 . 12 \times 65}{560} =0 . 130kg