Calculate the amount of heat required to melt 2 kg of lead having a melting point of 227 degrees.
| September 10, 2021 | education
Initial data: m (mass of lead for melting) = 2 kg; t0 (initial temperature) = 227 ºС.
Reference data: C (specific heat) = 140 J / (kg * K); λ (specific heat of fusion) = 25 * 10 ^ 3 J / kg; tmelt (melting point) = 327 ºС.
The required amount of heat for melting 2 kg of lead: Q = Q1 + Q2 = C * m * (tm – t0) + λ * m = (C * (tm – t0) + λ) * m.
Calculation: Q = (140 * (327 – 227) + 25 * 10 ^ 3) * 2 = 78,000 J = 78 kJ.
Answer: To melt 2 kg of lead, 78 kJ of heat is needed.
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.
