In a vessel with water, the mass of which is 2 kg at a temperature of 0 degrees, it floats in 0.5 kg of ice.
| February 22, 2021 | education
In a vessel with water, the mass of which is 2 kg at a temperature of 0 degrees, it floats in 0.5 kg of ice. How much heat does it take to bring water to a boil at normal atmospheric pressure?
mw = 2 kg.
t1 = 0 ° C.
t2 = 100 ° C.
ml = 0.5 kg.
C = 4200 J / kg * ° C.
q = 3.4 * 10 ^ 5 J / kg.
Q -?
Q = Q1 + Q2, where Q1 is the amount of heat that is needed to heat all the water, Q2 is the amount of heat needed to melt ice.
Q1 = C * (mw + ml) * (t2 – t1), where C is the specific heat capacity of water.
Q2 = q * ml, where q is the specific heat of ice melting.
Q = С * (mv + ml) * (t2 – t1) + q * ml.
Q = 4200 J / kg * ° C * (2 kg + 0.5 kg) * (100 ° C – 0 ° C) + 3.4 * 10 ^ 5 J / kg * 0.5 kg = 120,000 J.
Answer: you need Q = 120,000 J of thermal energy.
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