Water is heated from 14 degrees Celsius to 50 degrees Celsius by burning alcohol weighing 14 grams.

| January 7, 2021 | education

Water is heated from 14 degrees Celsius to 50 degrees Celsius by burning alcohol weighing 14 grams. In this case, all the energy released during the combustion of alcohol goes to heating the water. Find the mass of heated water. The specific heat capacity of water is 4200 J / kg multiplied by the degree Celsius. The specific heat of alcohol is 27,000,000 J / kg multiplied by the degree of Celsius

t1 = 14 ° C.
t2 = 50 ° C.
C = 4200 J / kg * ° C.
msp = 14 g = 0.014 kg.
q = 2.7 * 10 ^ 7 J / kg.
m -?
Since the loss of thermal energy can be neglected, the entire amount of heat Qsp, which is released during the combustion of alcohol, goes to heating water Qw: Qsp = Qw.
The amount of heat Qw, which is necessary for heating water, is expressed by the formula: Q = C * m * (t2 – t1), where C is the specific heat capacity of water, m is the mass of heated water, t2, t1 are the final and initial water temperatures.
The amount of heat Qsp, which is released during the combustion of alcohol, is expressed by the formula: Qsp = q * msp, where q is the specific heat of combustion of alcohol, msp is the mass of alcohol that has burned.
C * m * (t2 – t1) = q * msp.
m = q * msp / C * (t2 – t1).
m = 2.7 * 10 ^ 7 J / kg * 0.014 kg / 4200 J / kg * ° C * (50 ° C – 14 ° C) = 2.5 kg.
Answer: alcohol can be heated m = 2.5 kg of water.



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