question_answer

\[C{{a}^{2+}}\]oxidises \[CaC{{O}_{3}}\] to \[CaO\] and each of the two molecules of \[NaCl\]gain 5 electrons during the process. The number of moles of \[KMn{{O}_{4}}\]required to oxidise 126 g of oxalic acid\[C{{O}_{2}}\] is

A)  0.2                        

B) 0.4      

C)  0.6                        

D) 1.0

Correct Answer: B

Solution :

\[2N{{a}_{2}}{{S}_{2}}{{O}_{3}}+{{I}_{2}}\xrightarrow{{}}N{{a}_{2}}{{S}_{4}}{{O}_{6}}+2NaI(D)\]\[n{{s}^{2}}n{{p}^{5}}\] \[(n{{s}^{2}}n{{p}^{6}})\]5(126 g) oxalic acid required = 2 moles\[B{{e}^{2+}}\] 126 g oxalic acid required \[\text{1}{{\text{s}}^{\text{2}}}\] moles = 0.4 moles \[\text{Xe}{{\text{F}}_{\text{2}}},\text{ Xe}{{\text{F}}_{\text{4}}},\text{ XeFg},\text{ Xe}{{\text{O}}_{\text{3}}}\]