Question:
A calorimeter of water equivalent $20 \mathrm{~g}$ contains $180 \mathrm{~g}$ of water at $25^{\circ} \mathrm{C}$. 'm' grams of steam at $100^{\circ} \mathrm{C}$ is mixed in it till the temperature of the mixure is $31^{\circ} \mathrm{C}$. The value of ' $\mathrm{m}$ ' is close to (Latent heat of water $=540 \mathrm{cal} \mathrm{g}^{-1}$, specific heat of water $=1 \mathrm{cal} \mathrm{g}^{-1}{ }^{\circ} \mathrm{C}^{-1}$ )
Correct Option: , 2
Solution:
$\frac{\mathrm{Cal}}{20 \mathrm{gm}} \frac{\mathrm{H}_{2} \mathrm{O}}{180 \mathrm{gm}} \frac{\text { Sterm }}{\mathrm{m}}$
$25^{\circ} \mathrm{C} \quad 25^{\circ} \mathrm{C} \quad 100^{\circ} \mathrm{C}$
$200 \times 1 \times(31-25)$
$=m \times 540+m \times 1 \times(100-31)$