1. The problem statement, all variables and given/known data A refrigerator is to freeze 150g of water at 0°c in one minute, the ambient temperature being 20°C. Calculate in Watts the minimum power required? So known stuff: mass of water =0.15kg Temp of cold reservoir= 273k Temp of warm reservoir= 293k Specific heat capacity of water = 4190 J/kg k Specific latent heat of fusion of water= 3.33x105 J/kg 2. Relevant equations Q=mcΔt Q=±mLf COP= Q2/W W=Q1-Q2 Power=W/T Q1/Q2 = T1/T2 3. The attempt at a solution First off i thought good idea to work out how much energy would take to actually freeze all the water so which was like (0.15*4190*-20)+(0.15*-333000)= -62520 J (assume that means that 62520J was released to the system from the water as it converted to ice) I thought this was the Q1 value, then knowing T1 was 273 k and T2 was 293 k subbed into Q1/Q2 = T1/T2 to solve for Q2 which was (-62520)(293)/ (273) which gets Q2=-67000. But then Work done= Q1-Q2 so like -62520--67000= 4580J Then work done/time = power and then like 4580/60 = 76 Watts... but thats too small to freeze water that fast surely? Any ideas?