Question

In a calorimeter of water equivalent $20g$, water of mass $1.1kg$ is taken at $288K$ temperature. If steam at temperature $373K$ is passed through it and temperature of water increases by $6.5^{\circ }C$ then the mass of steam condensed is

• A. 17.5 g
• B. 11.7 g
• C. 15.7 g
• D. 18.2 g

Answer 1

Answer: (B)

Let mass of steam that gets condenced while the temperature of water is raised by $6.5^{\circ }C=xg$
So, heat released by steam $=540xcal+x\times 1\times 78.5$
$[Q=mL+ms\Delta T]$
This heat goes to the water + calorimeter system
$Q$ required by water $=1100\times 1\times 6.5=7150cal$
$Q$ required by calorimeter $=20\times 1\times 6.5=130cal$
$Q_{\text{released }}=Q_{\text{required }}$
$78.5x+540x=7150+130$
$x\simeq 11.7g$