Question

A sample of tin (Cp = 0.227 J/g•°C) is placed in a freezer. Its temperature decreases from 15.0°C to
–10.0°C as it releases 543 J of energy. What is the mass of the sample? Round your answer to three significant figures.

Use the formula q = mCes001-1.jpges001-2.jpgT.

g

Answer 1

ΔT = Tfinal − Tinitial = −10.0 − 15.0 = −25.0 °C (|ΔT| = 25.0 °C).

Use q = m C ΔT. Taking the magnitude of q (543 J) and ΔT (25.0 °C):

m = q / (C ΔT) = 543 J / (0.227 J/g·°C × 25.0 °C) = 543 / 5.675 = 95.7 g

(rounded to three significant figures).