How much energy will a zinc bar weighing about, 5 kg, taken at a temperature of 27 C, acquire during melting?
| July 24, 2021 | education
First, let’s calculate the amount of heat spent on heating the bar from t1 = 20 degrees to melting: (t2 = 420).
Q1 = c * m * (t2 – t1).
Q1 = 400 * 0.5 * (420 – 20) = 80,000 J.
Q2 = lambda * m. (lambda is the specific heat of fusion of zinc = 120,000 J / kg).
Q2 = 12000 * 0.5 = 60,000 J.
Q = Q1 + Q2.
Q = 80,000 + 60,000 = 140,000 J.
(0.14 MJ (megajoule) or 140 kJ)
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