0.5 l (0.5 kg) of milk was poured into an aluminum pan weighing 300 g. How much heat is required to heat a pot of milk from 20 to 100 degrees Celsius?
Given: m (weight of the aluminum pan) = 300 g = 0.3 kg; m2 (mass of poured milk) = 0.5 kg; t0 (initial temperature of the pan with milk) = 20 ºС; t (final temperature) = 100 ºС.
Constants: Ca (heat capacity of aluminum) = 920 J / (kg * K); Cm (heat capacity of milk) = 3940 J / (kg * K).
Heat for heating an aluminum pan with milk: Q = Q1 + Q2 = Ca * m1 * (t – t0) + Cm * m2 * (t – t0) = (t – t0) * (Ca * m1 + Cm * m2).
Calculation: Q = (100 – 20) * (920 * 0.3 + 3940 * 0.5) = 179680 J ≈ 180 kJ.
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