Question

The grams of one equivalent each for the indicated reaction.
\[{{H}_{2}}{{O}_{2}}(\to {{O}_{2}})\]
(a) 17g
(b) 51g
(c) 34g
(d) None of these

Answer 1

Hint: Start by writing the complete equation and balancing the components. Then find out and calculate the parameters required to calculate gram equivalent.

Complete step by step answer:
Equivalent weight is also known as gram equivalent). It is defined as, “the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance”. In other words, “the equivalent weight of an element is defined as the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. These values correspond to the atomic weight divided by the usual valence”.
One equivalent is the amount of a substance which reacts with an arbitrary amount of another substance in a given chemical reaction.
In the given reaction, hydrogen peroxide acts as a reductant.

The complete reaction can be written as –
\[{{H}_{2}}{{O}_{2}}\to {{O}_{2}}+2{{H}^{+}}+2{{e}^{-}}\]
As we can see, there is net exchange of 2 electrons. So, the n-factor is 2.
Also, Molecular weight of \[{{H}_{2}}{{O}_{2}}\] is
\[\begin{align}
& =(2×1)+(2×16) \\
& =2+32 \\
& =34 \\
\end{align}\]
\[\because Eq.wt.=\dfrac{Mol.wt.}{n-factor}\]
Equivalent weight of\[{{H}_{2}}{{O}_{2}}=\dfrac{34}{2}=17\]
Therefore, the answer is option (a) 17g.

Note: Hydrogen peroxide is also known as Perhydrol, Oxydol and Superoxol. It is used as a powerful bleaching agent, disinfectant and oxidizer. It is non-flammable, but being a powerful oxidizing agent, it can cause spontaneous combustion when it comes in contact with organic material.