Question

Which one of the following reactions is an example of auto-catalysis?

• A. $2As{{H}_{3}}(s)\xrightarrow{{}}2As(s)+3{{H}_{2}}(g)$
• B. ${{N}_{2}}(g)+3{{H}_{2}}(g)\xrightarrow{Fe(s)}2N{{H}_{3}}(g)$
• C. $2S{{O}_{2}}(g){{O}_{2}}(g)\xrightarrow{NO(g)}2S{{O}_{3}}(g)$
• D. ${{C}_{12}}{{H}_{22}}{{O}_{11}}(l)+{{H}_{2}}O(l)\xrightarrow{{{H}^{+}}(l)}$ ${{C}_{6}}{{H}_{12}}{{O}_{6}}(l)+{{C}_{6}}{{H}_{12}}{{O}_{6}}(l)$

Answer 1

Answer: (A)

$2As{{H}_{3}}(s)\xrightarrow{{}}2As(s)+3{{H}_{2}}(g)$

Answer 2

The reactions which are catalysed by one of the product formed, are called autocatalysis reactions and the process is called autocatalysis eg, $2As{{H}_{3}}(g)\xrightarrow{{}}2As(g)+3{{H}_{2}}(g)$