The temperature of 1500 g of ethanol is 37°C. What will the final temperature be if 80,000 J of energy as heat is added to the enthanol? Ethanol has a specific heat of 2.44 J/g°C.

Question

The temperature of 1500 g of ethanol is 37°C. What will the final temperature be if 80,000 J of energy as heat is added to the enthanol? Ethanol has a specific heat of 2.44 J/g°C.

Answer:

a)22°C

b)51°C

c)59°C

d)67°C

Answer 1

q = mCΔT

q = heat = 80,000 J

m = mass = 1500 g

C = specific heat = 2.44 J/g/deg

ΔT = change in temp = ?

ΔT = q/(m)(C) = 80,000J/1500g x 2.44 J/g/deg = 21.9 degrees

Final temperature = 37 + 21.9 = 58.9^oC = 59⁰C = Answer (c)

Answer 2

First we need to pull the important information from the question.

1500 g Ethanol

Ti = 37C

q = 80000J

c = 2.44 J/gC

What is the final T?

Next we need to identify the proper equation. When dealing with questions of heat and temperature of a substance, calorimetry is usually a good place to start.

q = mc(Tf-Ti)

If we look at the equation we see that we have all of the pieces but one, Tf. Which is great because that is what this question is asking for. We've got our information and the right equation. If we solve the equation above for Tf we get.

Tf = (q/mc) + Ti

Inputing our values from the question we get value of 58.9 degrees C. This is very close to the 59C listed on the multiple choices. Now we must ask ourselves, does it make sense that putting energy into ethanol would raise it's temperature? We put in a lot of energy but it was also into a lot of ethanol. So our answer makes sense.