[optimism]

Good afternoon all
I am a new member here
I hope find every thing about chemistry here & be a useful member too 

My question is :

A quantity of (4.00*10^2 ml )of 100.600 M HNO3 is mixed with (4.00*10^2 ml) of 0.300 M Ba(OH)2 in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of both solutions is the same at 18.46 Celsius. What is the final temperature of the solution?

[Tybalt]

I think, in order to find the final temp. you need to know the specific heat capacity to find the unknown variable.