ThermoChemistry
posted by LaurenB on .
When 19 mL of water at 22 C is combined with 18 mL of water at 64 C, what is the final temperature of the water?. The specific heat of water is 4.184 J/g/K and its density is 1.0 g/mL.

c_hot = (4.184J/g*K)(18mL)(1g/mL)
c_cold = (4.184J/g*K)(19mL)(1g/mL)
Use:
0 = c_hot(T_f  T_initial,hot)+ c_cold(T_f  T_initial,cold)
Solve for T_f and remember to convert temperature back to C from Kelvin and vice versa.
Best of luck,
ChemVantage Loather 
Just a quick note to say that changing celsius to kelvin and back again is not necessary. Since it is a difference of temperatures only, and since 1 degree C = 1 degree K, you may subtract with C or K and come up with the same value.