Question

1 g of ice at $0{}^{o}C$ is added to 5 g of water at $10{}^{o}C$. If the latent heat is 80 cal/g, the final temperature of the mixture is:

• A. $5{}^{o}C$
• B. $0{}^{o}C$
• C. $-5{}^{o}C$
• D. None of the above

Answer 1

The correct option is B $0{}^{o}C$

According to principle of calorimetry,
$Heatlostbywater=Heatgainedbyice$
$5\times 1(10-\theta )=(1\times 80)+1\left(1\right)(\theta -0)$
$50-5\theta =80+\theta$
$-30=6\theta$
$\theta =-5$
Since $\theta$ is negative all the ice did not melt, so final temperature is $0{}^{o}C$