Question

A metal rod is heated to 100°C and then dropped into a calorimeter containing 1 kg of water at 20.0°C. If the final equilibrium temperature of the mixed system is 21 °C, then the specific heat of

the metal is 448 J/kg °C, what is the mass of the metal rod? (The specific heat of water = 4186 J/kg °C)
A) 4.186 J
B) 1.1 kg
C) 111 g
D) 110 g​

Answer 1

Answer: 0.12 kg

Step-by-step explanation:

let mass of iron rod be m kg

now Q1 = m × 448 × (100-21) = 35392m J

Q2 = 1 × 4186 × (21 - 20) = 4186 J

Now, Q1 = Q2

⇒35393m = 4186

⇒ m = 4186/35392 = 0.12 kg