Question

An iron bar at 325 K is placed in a sample of water. The iron bar gains energy from the water if the temperature of the water is

(1) 65 K (3) 65°C
(2) 45 K (4) 45°C

Answer 1

So what you need to do is to have all your answers in the same unit as the one in the question which is K then look for the one that is greater than that in the question because only then will it absorb heat from the water.

temp. of rod: 325K
(1) 65 K
(2) 45 K
(3) 65° C = (65 + 273) K = 338 K
(4) 45° C = (45 + 273) K = 318 K

⇒ option 3 is the answer