Help with basic college chemistry

[Douwant2ply]

So I have a chemistry final today and I am stuck on one of my review problems and the prof. doesn't want to help me set this up to get the correct answer, I believe because a similar problem will be on the exam. Anyway if anybody is a chem major/teacher/enthusiast/just knows some chemistry can you help me out? Here is the problem that has kept me awake the past few nights (and for once its not the fault of my tank!):

A 100.g iron ball(specific Heat = 0.473 J/g*C) is heated to 125*C and is placed in a calorimeter holding 200 g of water at 25*C. What will be the highest temperature reached by the water?

(* = Degrees symbol)

thanks in advance for the help

[Rgwiz11]

hey douwant2ply,

I teach high school physics and chemistry.

Looks to be a heat transfer question. The formula you would want to use is

m1*cp1*dT1 = m2*cp2*dT2

m1 = mass of the iron ball

cp1 = specific heat capacity of the iron

dT1 = change in temperature of the iron (initial temp - final temp)

m2 = mass of water

cp2 = specific heat capacity of water (4.186 J/g*C)

dT2 = change in temp of water (final temp - initial temp)

*note that the change in temp has to be positive for both the iron and water*

because the iron and water will reach temperature equilibrium, they will have the same final temperature. I'll use T for that variable.

Your equation then, should look like:

(100 * 0.473)(125-T) = (200 * 4.186)(T-25)

multiply it out and you should get

5912.5 - 47.3T = 837.2T - 20930

add like terms and get

26842.5 = 884.5T

solve for T:

T = 30.34 degrees Celsius

[Douwant2ply]

Lifesaver!!!! Thank you! I think I was trying so hard to solve the problem I completely overlooked the Specific heat of Water, which was throwing me off on putting everything into the equation. Thank you, I really appreciate it.