How much heat needs to be spent to melt 100 g of ice at 0 ° C? 100 g of ice at -20 ° C?
| April 25, 2021 | education
m = 100 g = 0.1 kg.
t1 = 0 ° C.
t2 = – 20 ° C.
C = 2100 J / kg * ° C.
λ = 330 * 10 ^ 3 J / kg.
Q1 -?
Q2 -?
The amount of heat Q1 required to melt ice at the melting temperature is determined by the formula: Q1 = λ * m, where λ is the specific heat of melting, m is the mass of ice.
Q1 = 330 * 10 ^ 3 J / kg * 0.1 kg = 33 * 10 ^ 3 J.
The amount of heat Q2 required for melting ice taken at a temperature of t2 is determined by the formula: Q2 = C * m * (t1 – t2) + λ * m, where C is the specific heat capacity of ice, t2 is the initial ice temperature, t1 is the melting point of ice.
Q2 = 2100 J / kg * ° C * 0.1 kg * (0 ° C – (- 20 ° C) + 330 * 10 ^ 3 J / kg * 0.1 kg = 37200 J.
Answer: Q1 = 33 * 10 ^ 3 J, Q2 = 37200 J.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
