Which one of the following methods is used to prepare carbon monoxide on commercial scale?
Which one of the following methods is used to prepare carbon monoxide on commercial scale?
Dehydration of formic acid with conc. $\mathrm{H}_2 \mathrm{SO}_4$
Direct oxidation of C in limited supply of oxygen
Passing steam over hot coke
Heating lime stone
Solution
(a) When formic acid $\mathrm{HCOOH}$ is dehydrated with $\mathrm{H}_2 \mathrm{SO}_4$ (conc.), it gives carbon monoxide (CO) and $\mathrm{H}_2 \mathrm{O}$ as :
$
\mathrm{HCOOH}+\mathrm{H}_2 \mathrm{SO}_4 \text { (conc.) } \longrightarrow \mathrm{CO}+\mathrm{H}_2 \mathrm{O}+\mathrm{H}_2 \mathrm{SO}_4
$
But the above process is not used on commercial scale.
(b) Direct oxidation of carbon in limited supply of oxygen can give $\mathrm{CO}$ but the process is not used on commercial scale.
$
2 \mathrm{C}+\mathrm{O}_2 \text { (limited supply) } \longrightarrow 2 \mathrm{CO}
$
(c) When steam $\left(\mathrm{H}_2 \mathrm{O}\right)$ is passed over coke $(\mathrm{C})$, it gives $\mathrm{CO}+\mathrm{H}_2$, as :
$
\text { Coke }(\mathrm{C})+\underset{(\text { Steam) }}{\mathrm{H}_2 \mathrm{O}} \stackrel{\Delta}{\mathrm{Ni}} \mathrm{CO}(g)+\mathrm{H}_2(g)
$
The above process can be used to produce (CO) on commercial scale.
(d) Lime stone is $\mathrm{CaCO}_3$, on heating it gives oxygen $\left(\mathrm{O}_2\right)$ and $\mathrm{CaO}$ as :
$
\mathrm{CaCO}_3 \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{O}_2
$
Hence, option (c) is the correct answer