Question

Which of these will not react with Acetylene?

• A. $\mathrm{Na}$
• B. $\mathrm{HCl}$
• C. $\mathrm{NaOH}$
• D. Ammonical ${\mathrm{AgNO}}_3$

Answer 1

The correct option is C

$\mathrm{NaOH}$

Explanation for correct option:

C. $\mathrm{NaOH}$

Acetylene is a weak acid while sodium hydroxide is a strong base. Thus there will be no reaction between acetylene and sodium hydroxide.

${\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)\to \mathrm{No}\mathrm{reaction}$

Explanation for incorrect options:

A. $\mathrm{Na}$

• Sodium reacts with acetylene to produce sodium hydro acetylide$\left({\mathrm{NaHC}}_2\right)$ and hydrogen.
• The chemical reaction can be depicted as:

$\mathrm{Na}\left(\mathrm{s}\right)+{\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)\to {\mathrm{NaHC}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$

B. $\mathrm{HCl}$

• Acetylene reacts with hydrochloric acid and produces 1,1-Dichloroethane $\left({\mathrm{CH}}_3{\mathrm{CHCl}}_2\right)$.
• The chemical reaction can be depicted as:

$$\begin{gathered} {\mathrm{C}}_2{\mathrm{H}}_2+\mathrm{HCl}\to {\mathrm{CH}}_2=\mathrm{CHCl} \\ {\mathrm{CH}}_2=\mathrm{CHCl}+\mathrm{HCl}\to {\mathrm{CH}}_3{\mathrm{CHCl}}_2 \end{gathered}$$

D. Ammonical ${\mathrm{AgNO}}_3$

• Acetylene with ammonical silver nitrate$\left({\mathrm{AgNO}}_3\right)$ produces silver acetylide$\left({\mathrm{C}}_2{\mathrm{Ag}}_2\right)$ with ammonium nitrate$\left({\mathrm{NH}}_4{\mathrm{NO}}_3\right)$ and water.
• The chemical reaction can be depicted as:

${\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)+2{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)+2{\mathrm{NH}}_4\mathrm{OH}\left(\mathrm{aq}\right)\to {\mathrm{C}}_2{\mathrm{Ag}}_2\left(\mathrm{aq}\right)+2{\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Hence, the correct option is A i.e. $\mathrm{NaOH}$ does not react with acetylene.