Calculate the temperature change when 1575 J of heat are removed from an 85.0 gram sample of ethyl alcohol originally at 23.5 °C.

Answer.

We can obtain the specific heat of ethyl alcohol from the table in our lecture notes. It is 2.45 J ­ g^-1 ­ °C^-1. Using the relationship,

we need to rearrange to solve for temperature,

Substituting,

So the temperature change is 7.72 °C.

Now can you calculate the final temperature of the sample of ethyl alcohol?

This is a little tricky, what we have to what out for is that the heat is REMOVED! So the final temperature is,

T_final = 23.5 °C - 7.72 °C = 15.8 °C