540 g of ice at `0^(@)C` is mixed with 540 g of water at `80^(@)C`. The final temperature of the mixture is

Options

A. `0^(@)C`
B. `40^(@)C`
C. `80^(@)C`
D. less than `0^(@)C`

Answer

A

Explanation

Heat taken by ice to melt at `0^(@)C "is" Q_(2) = "m"L = 540xx80 = 43200"cal"`
Heat given by water to cool upto `0^(@)C "is" Q_(2) = "ms"Deltatheta = 540 xx 1 x (80-0) = 43200"cal"`
Hence heat given by water is just sufficient to melt the whole ice and final temperature of mixture is `0^(@)C`.