(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

You cool a 100g slug of red-hot iron (temperature 745 degrees C) by dropping it into an insulated cup of negligible mass containing 85g of water at 20 degrees C. Assuming no heat exchange with the surroundings, what is the final temperature of the water?

2. Relevant equations

Q=mcΔT

Q=mL

specific heat of water c=4190 J/kgK

specific heat of iron c=470 J/kgK

Heat of vaporization of water L=2256 x 10^3 J/kg

3. The attempt at a solution

I've looked at several other similar threads on the forums, but I'm not really looking for an answer, just some clarification of some points that I haven't quite grasped yet.

My initial attempt at a solution entailed Q(water) + Q(heat) = 0, but this method gave me an answer of 104 degrees C, which implies some of the water changes phase, so I know I need to include Q=ml in my equation to account for that, but I don't really see how to do that.

Some direction would be greatly appreciated. Thank you!

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# Homework Help: Finding thermal equilibrium of hot iron placed in water

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