Question

$5g$ of steam at ${100}^{0}C$ is mixed with $5g$ of the ice at $0^{0}C$. The final temperature of the mixture is :

• A. ${100}^{0}C$
• B. ${90}^{0}C$
• C. ${95}^{0}C$
• D. ${80}^{0}C$

Answer 1

Answer: (A)

${100}^{0}C$

Latent heat of fusion is $336J/g$

Latent heat of vaporization is $2260J/g$

So, Heat released by $5g$ of steam to condense is $Q_1=5\times {10}^{-3}\times 2260\times {10}^3$

and, Heat absorbed by $5g$ of ice to melt is $Q_2=5\times {10}^{-3}\times 336\times {10}^3$

Heat require to increase temperature from $0^{o}Cto{100}^{o}C$ is $Q_3=mc\Delta T=5\times {10}^{-3}\times 4200\times 100=2100J$

As, $Q_1>Q_2+Q_3$

Hence, final temperature is at ${100}^{o}C$.

Partial steam will condense.