2C6H6(l) + 15O2(g) -> 12CO2(g) + 6H2O(l) + 6542 kJ

Question

If the heat from burning 7.000 g of C6H6 is added to 5691 g of water at 21 degrees C what is the final temperature of the water?

Answer 1

How much energy do you obtain from the combustion of benzene?
That is 6542 x (7 g/2*78g) = about 293 kJ or 293,000 J.
Then 293,000 = mass H2O x specific heat H2O x (Tfinal-Tinitial).
Solve for Tfinal. Those numbers above are approximate; you should go through it with your calculator to obtain a more accurate reading.

Answer 2

your approximations are very accurate.. thanks!

Answer 3

is the final and intial temperature in kelvin or celcius my calculations seem off