A metal sample of mass 50.0 g is heated from 25.0 °C to 100.0 °C. If the metal has a specific heat capacity of 0.385 J/g·K, how many joules of heat are required?

• A. 1,320 J
• B. 1,444 J
• C. 1,500 J
• D. 1,380 J

Answer: (B)

Heat gained by a substance is found from q = m c ΔT, where m is mass, c is specific heat, and ΔT is the temperature change. The metal’s mass is 50.0 g, its specific heat is 0.385 J/g·K, and the temperature rises from 25.0 °C to 100.0 °C, so ΔT = 75.0 K.

Compute the heat: 50.0 g × 0.385 J/g·K × 75.0 K = 50.0 × 0.385 × 75 ≈ 1,443.75 J. With the given significant figures, this rounds to 1,444 J. The amount of heat required is 1,444 joules.