Carbon monoxide is always present in

Options

A. automobile exhausts
B. volcanic gases
C. gases coming out of furnaces
D. all of these

Answer

D

Explanation

Carbon monoxide is produced when any carbon - containing compound (petrol, diesel, `CNG`), including carbon itself, is burned with an amount of oxygen insufficient for complete combustion:
`2(C ) + O_(2)(g) rarr 2CO(g)`
As automobile engines have become more efficient, `CO` production has diminished substantially. Thus, in that respect, the air inhaled on city streets is less harmful than it used to be because its `CO` content is lower.