Question

find the final equilibirum temperature when 10.0 g of milk at 10.0degC is added to 1.60*10^2 g of coffee with a temperatrure of 90.0degC. Assume the specific heats of coffee and milk are the same as for water (Cp,w=4.19J/g*degC) and disregard the heat capacity of the container


massmilk*cmilk*(Tf-10)+masscoffee(ccoffee)(Tf-90)=0
please show me in simple steps how to solve for Tf

thanks a lot

Answer 1

massmilk*cmilk*(Tf-10)+masscoffee(ccoffee)(Tf-90)=0

divide through by specific heat, it goes away.

10*(Tf-10)+160(Tf-90)=0
Tf(10+160)-100-160*90=0
Tf= (14400/170)

Answer 2

so Tf is 84.70?

Answer 3

the Tf is about 85.3°C because it's actually Tf = 14,500/170