You add 500 mL of water at 10°C to 100 mL of water at 70°C. What is the most likely final temperature of the mixture?

1 Answer
Aug 2, 2017

Would it not be the weighted average of the two temperatures....?

Explanation:

Suppose we knew of heat capacities (and we don't here because you have not quoted any). In a problem like this would we not expect that the final temperature is the WEIGHTED average of the two temperatures, according to the mass of each volume?

500mL×10C+100mL×70C500mL+100mL=20C.....

Anyway, you should check your text for a more sophisticated approach. But note that this calculation is quite amenable to a simple experiment, given a couple of beakers or polystyrene cups, and a thermometer. What did you find in the experiment?