Question

How much ice at -20°c must be dropped on 0.5 kilograms of water initially at 20°c in oder for the final temperature to be 0°c with the ice all melted. Heat capacity of container can be neglected

Answer 1

Specific heat capacity of water $C=4184J/kg$ $/K$

Specific heat capacity of Ice $=2093Jkg^{-1}K^{-1}$

$L_f=334000J/kg$

Heat lost by water $=mc\Delta\>\theta$

$=0.5×4184×20$

$=41840J$

Heat gained by ice$=m(2093)(20)+m(334000)$

$=375860m$

$375860m=41840$

$m=0.1113kg$