Question

10 g of ice at $-{10}^{\circ }C$ is added to 10g of water at ${85}^{\circ }C$. What is the final temperature and amount of ice left in the system ?(System is kept inside an ideal insulator)

• A. $0^{\circ }C,0g$
• B. $0^{\circ }C,2g$
• C. ${37.5}^{\circ }C,0g$
• D. ${37.5}^{\circ }C,5g$

Answer 1

Answer: (A)

The correct option is A $0^{\circ }C,0g$
$m_i{c}_i{\theta }_i+m_{i}L+m_i{c}_w({\theta }_0-0)=m_w{c}_w(85-{\theta }_0)$
Since m_i=m_w= 10g
2.1(10) + 336- 4.2(${\theta }_0$)= 4.2(85-${\theta }_0$)
21+ 336- 357= 8.4${\theta }_0$= 0
Thus, eventually 0g ice will be present and final temperature of system will be $0^{o}C$