What was the initial temperature of the copper?

[bigboss]

Homework Statement

8.0 g of aluminum at 200 C and 22 g of copper are dropped into 55 cm^3 of ethyl alcohol at 15 C. The temperature quickly comes to 28 C. What was the initial temperature of the copper?

Homework Equations

The Attempt at a Solution

tried using calorimetry equations, not getting anywhere.

 

[pat666]

Have to give the equations i haven done SHC for 3years although i don't think that that question is hard.

 

[bigboss]

heat lost = heat gained
or m1 * s1 * t1 + m2 * s2 * t2 + m3 * L = m1 * s1 * tf + m2 * s2 * tf + m3 * s3 * tf
solving the above equation for t2 we get
t2 = (m1 * s1/m2 * s2) * (tf - t1) + (m3/m2 * s2) * (s3 * tf - L)
m1 = 11 g = 11 * 10^-3 kg
s1 = 900 J/kg/K
t1 = 200 oC = (200 + 273) K = 473 K
m2 = 21 g = 21 * 10^-3 kg
s2 = 387 J/kg/K
t2 = the initial temperature of copper
m3 = ρ * V = 790 * 46 * (10^-2)^3 = 36.34 * 10^-3 kg
L is the latent heat of fusion of ethyl alcohol and is equal to 1.08 * 10^5 J/kg
tf = 22 oC = (22 + 273) K = 295 Knot working.

 

[ehild]

I do not see any water in the problem.

ehild

 

[bigboss]

thanks for the notice, edited it, and stil not getting the correct answer