Question

A piece of zinc at a temperature of 20⁰C weighing 65.38 g is dropped into 180 g of boiling water (T = 100⁰C). The specific heat of zinc is 0.4 J g–1 C–1 and that of water is 4.2 J g–1⁰C–1. What is the final common temperature reached by both the zinc and water ?

• A. 97.3⁰C
• B. 33.4⁰C
• C. 80.1⁰C
• D. 60.0⁰C

Answer 1

Answer: (A)

97.3⁰C

Answer 2

Let final common temperature is Tf

Heat gained by Zinc piece = Heat lost by water

0.4 (Tf – 20) × 65.38 = 4.2 (100 –Tf) × 180

$\Rightarrow$ Tf = 97.3 ⁰C