Question

When m g of water at ${10}^o$C is mixed with m g of ice at $0^o$C, which of the following statements are false?

• A. The temperature of the system will be given by the equation, $m\times 80+m\times 1\times (T-0)=m\times 1\times (50-T)$.
• B. Whole of ice will melt and temperature will be more than or equal to $0^o$C but lesser than ${10}^o$C
• C. Whole of ice will melt and temperature will be $0^o$C
• D. Whole of water will be at $0^o$C

Answer 1

The correct option is A The temperature of the system will be given by the equation, $m\times 80+m\times 1\times (T-0)=m\times 1\times (50-T)$.

Required heat to melt $m$g of ice $=m\times 80cal$

Released heat by water $=m\times 1\times (10-0)=10mcal$

Released heat is less than required heat so final temperature is $0^{o}C$.

Whole ice will melt and temperature will be $0^{o}C$ because during phase change temperature remains constant and by above equations it is seen that final temperature will be $0^{o}C$.