Question

Which is the gas evolved when carboxylic acids react with strongly electropositive metals (such as Na, K, Ca, Zn)?

Options

• O₂

• CO₂

• H₂

• H₂O vapour

Answer 1

H₂

Explanation:

With the effervescence of hydrogen gas, carboxylic acids react with strongly electropositive metals (such as Na, K, Ca, Zn, etc.) to produce the corresponding salts.

\[\begin{array}{cc}
\phantom{}\ce{O}\phantom{...............................}\ce{O}\phantom{...................}\\
\phantom{}||\phantom{................................}||\phantom{...................}\\
\ce{\underset{Carboxylic acid}{2R - C - OH} + \underset{Sodium metal}{2Na} -> \underset{Sodium salt of carboxylic acid}{2R - C - O^-Na^+} + \underset{Hydrogen gas}{H2 ^}}
\end{array}\]