A 35g sample of Fe is dropped into 80g of water at 20 degrees Celsius. What is the final (equilibrium) temperature of the iron/water?

Question

This isn't really a chemistry problem. There will be no chemical reaction. It is a heat capacity (physics) problem.

Use the specfic heats of iron and water, and set the heat loss of the iron equal to the heat gain of the water, when reaching the final temperature Tf.
35*CFe*(80 - Tf) = 80*Cw*(Tf-20)
CFe is the specific heat of Fe and Cw is the specific hdeat of water. Look up CFe and solve for Tf.