Answer to Question #142288 in General Chemistry for Bbaieee

Question

Assume that 0.401 g of diborane is combusted in a calorimeter whose heat capacity (Ccalorimeter) is 7.854 kJ/°C at 25.59°C. What is the final temperature of the calorimeter?

Answer 1

=> Heat of combustion of diborane = -1941KJ/mol.

=> for 0.401 g Diborane , mole = 0.0154

So heat of combustion = 0.0154$\times (-1941) = -29.89 KJ$ .

Now if final temperature is T, then from equation $-29.89KJ = C(T-25.59)$

$=> T-25.59 = -3.805$

=> Final temperature = $T= 21.78^0 C$