A33.0 g iron rod, initially at 22.7 ∘c, is submerged into an unknown mass of water at 63.3 ∘c, in an insulated container. the final temperature of the mixture upon reaching thermal equilibrium is 58.5 ∘c. part a what is the mass of the water? express your answer to two significant figures and include the appropriate units.

When the iron and the water reach thermal equilibrium, they have same temperature, .
We can consider this as an isolated system, so the heat released by the water is equal to the heat absorbed by the iron.

The hear released by the water is:

where is the water mass, is the specific heat of the water, and is the variation of temperature of the water.

Similarly, the heat absorbed by the iron is:

where is the iron mass, is the iron specific heat, and is the variation of temperature of the iron.

Writing and replacing the numbers, we can solve to find mw, the mass of the water: