Question

If 8.800 g of c6h6 is burned and the heat produced from the burning is added to 5691 g of water at 21 °c, what is the final temperature of the water?

Answer 1

Before we solve for the final temperature, the initial temperature should be given. Suppose this is at room temperature, 25°C. The solution is as follows.

8.8 g(1/Molar mass of benzene)(Heat of combustion of benzene) = 5,691 g water(Heat capacity of water)(Tfinal - Tinitial)

Heat from benzene = - Heat from water
8.8 g(1/78 g/mol)(-3,271 kJ/mol) = -(5,691 g)(4.816 J/g·°C)(1 kJ/1000 J)(Tfinal - 25°C)
Tfinal = 38.46°C