please show me a simple formula to solve this

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 temperature 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

thanks!

Answer 1

The sum of the heats gained is zero.
Heat gained = mass*c*(Tf-Ti)

So here...

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

If the c are the same, they divide out.
Solve for Tf

Answer 2

ok thnx
i'll try it