An insulated beaker with negligible mass contains liquid water with a mass of 0.280kg and a temperature of 85.0?C .
How much ice at a temperature of -21.3?C must be dropped into the water so that the final temperature of the system will be 38.0?C ?
Take the specific heat of liquid water to be 4190J/kg?K , the specific heat of ice to be 2100J/kg?K , and the heat of fusion for water to be 3.34×105J/kg .