Chemistry WebAssign Help!?

Question

If anyone can help with this problem, your response is greatly appreciated. Thanks!!

An ice cube tray holds 355 g water. If the water initially has a temperature of 31°C, how many kilojoules of heat must be removed to cool and freeze the water at 0°C?

Answer 1

Qcool=m*c*deltaT - this will bring the water to 0degC
Qtotal =Qcool+Qfreeze


Q=0.355kg*4.81kJ/(K*kg)*31K
work this out yourself - I took c from memory so you may have to check that.

to freeze it you need to add

Qfreeze= m*deltaHmelt
deltaHmelt = 334kJ/kg

Answer 2

Q = mc∆T + mH = m(c∆T + H)
Q = (355 g)(4.184 J/cal)[(31°C)(1 cal/g°C) + 79.72 cal/g]