What amount of heat is required to melt 1.5 kg of zinc, the initial temperature of which is 20 degrees?
| June 16, 2021 | education
m = 1.5 kg.
t1 = 20 ° C.
t2 = 420 ° C.
С = 380 J / kg * ° C.
q = 1.2 * 105 J / kg.
Q -?
Q = C * m * (t2 – t1) + q * m = (C * (t2 – t1) + q) * m.
Q = (380 J / kg * ° C * (420 ° C – 20 ° C) + 1.2 * 105 J / kg) * 1.5 kg = 408000 J.
Answer: to melt zinc, you need Q = 408000 J of thermal energy.
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