How much energy will a zinc bar weighing 0.5 kg acquire when melted at a temperature of 20 degrees?

univerkov | July 22, 2021 | education

Initial data: m (bar weight) = 0.5 kg; tн (initial temperature of the bar) = 20 ºС.

Reference data: tpl. (zinc melting point) = 419.6 ºС; C (specific heat of zinc) = 400 J / (kg * K); λ (specific heat of fusion of zinc) = 112.2 * 10 ^ 3 J / kg.

The energy that the bar will acquire: Q = Q1 + Q2 = C * m * (tpl – tn) + λ * m.

Let’s perform the calculation: Q = 400 * 0.5 * (419.6 – 20) + 112.2 * 10 ^ 3 * 0.5 = 136,020 J.

Answer: A zinc bar when melted will acquire 136,020 Joules of thermal energy.

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.