Enthalpy of combustion of carbon to`CO_(2)` is - 393.5 kj `mol^(-1)`. Calculate the heat released upon formation of 35.2 g of `CO_(2)` from carbon and dioxygen gas.

Explanation

We are given that.
`Delta ""_(c)H= - 393 .5 kj mol^(-1)`
We are to calculate the heat released upon formation of 35.2 g.
The reaction is `C + O_(2) to CO_(2)`.
Enthalpy of combustion is the heat relaeased when 1 mole of substance is completely burnt in air.
i.e., 12 g of C is brunt to give 44 g of `CO_(2)` to give - 393.5 kj `mol^(-1)` of heat.
During the formation of 44 g of `CO_(2)` heat released = - `(393.5)/(44) xx 35.2`
`=(-3935)/(44) xx (352)/(100) = - 314.80 kj mol^(-1)`