A mixture of CO and `CO_2` having a volume of 30 mL is mixed with x " mL of " `O_2` and electrically sparked. The volume after explosion is `(20+x)` mL under the same condition. What would be the residual volume if 45 " mL of " the original mixture is treated with aueous NaOH?
(a). 10 mL
(b). 20 mL
(c). 30 mL
(d). mL

Explanation

`CO(g)+(1)/(2)O_2(g)toCO_2(g)`
`"Final"-(x-(y)/(2))mL ymL`
`CO_2(g)+O_2(g)to` no reaction
`underline("Total volume of gases left"=(30-y)+(x-(y)/(2))+y=(20+x))`
`thereforey=20mL`
In `45 mL, V_(CO)=(20)/(30)xx45=30mL`
and `V_(CO_2)=45-30=15mL`
Only `CO_2` reacts with `NaOH`, so `15 " mL of " CO_2` reacts.
`therefore` reasidual volume `V_(CO)=30mL`