Assume that $0\mathrm{.}451g$ of diborane is combusted in a calorimeter whose heat capacity $(C_{\text{c}\text{a}\text{l}\text{o}\text{r}\text{i}\text{m}\text{e}\text{t}\text{e}\text{r}})$ is $7\mathrm{.}854k\frac{J}{}C$ at $21\mathrm{.}61C.$ What is the final temperature of the calorimeter?

$C$