5 g of water at `30^@C` and 5 g of ice at `-20^@C` are mixed together in a calorimeter Find the final temperature of the mixure. Assume water equivalent of calorimeter to be negligible, sp. Heats of ice and water are 0.5 and `1 cal//g C^@`, and latent heat of ice is `80 cal//g`

Options

A. `0^(@)C`
B. `10^(@)C`
C. `-30^(@)C`
D. `gt10^(@)C`

Answer

A

Explanation

Let final temperature be 0°C with m gram of ice melted.
Heat gained by Ice = Heat lost by water.
`ice_(-20^(@)C)toi_(0^(@)C)+(i_(0^(@)C)toW_(0^(@)C))=W"ater " 30^(@)Cto"Water " 0^(@)C`
`5xx0.5xx20+mxx80=5xx1xx30,m=(100)/(80)gmlt5`
So, final temperature is 0°C.