Heat of combustion of carbon to `CO_(2)` is -393.5 kJ/mol. The heat released upon the formation of 35.2 kg of `CO_(2)` from carbon and oxygen gas is-

Options

A. `-315kJ`
B. `+315kJ`
C. `-630kJ`
D. `-3.15kJ`

Answer

A

Explanation

`C(s)+O_(2)(g)toCO_(2)(g),Delta_(f)H=-393.5kJ*mol^(-1)`
Heat released on formation of 44g `CO_(2)=-395.5kJ*mol^(-1)`
`therefore` Heat released on formation of 35.2g of `CO_(2)=-(393.5kJ*mol^(-1))/(44g)xx35.2g=-315kJ*mol^(-1)`.