Question

An insulated beaker with negligible mass contains liquid water with a mass of 0.270 kg and a temperature of 78.7 ?C .

How much ice at a temperature of -14.0 ?C must be dropped into the water so that the final temperature of the system will be 40.0 ?C ?

Take the specific heat of liquid water to be 4190 J/kg?K , the specific heat of ice to be 2100 J/kg?K , and the heat of fusion for water to be 3.34×10⁵ J/kg .

Answer 1

MCw Tw = m [Cice Tice + L +Cw T )

Amount of ice that must be added is

m = MCw Tw /[ Cice Tice + L +Cw T ]

here Cw = 4190, Tw = (78.7 - 40.0) ,Cice = 2100, Tice = 14.0, L = 334000 , M =0.270, T = 40.0

substituting the values

m = 0.08245kg

= 82.45 grams