Step-by-step explanation:
Heat flow = conductivity × area × change in temperature / thickness
q' = kAΔT/t
13.3 W = k (1.56 m²) (7.8°C) / (0.0234 m)
k = 0.0256 W/m/°C
Heat lost by water = heat gained by ice
-mCΔT = mL + mCΔT
-(1000 g) (1 cal/g/°C) (12°C − 37°C) = m (79.7 cal/g) + m (1 cal/g/°C) (12°C − 0°C)
25,000 cal = (91.7 cal/g) m
m = 272.6 g