A) Zn acts as an oxidising agent when it reacts with \[HN{{O}_{3}}\]
B) \[HN{{O}_{3}}\] is weaker acid than \[{{H}_{2}}S{{O}_{4}}\]and HCl
C) In electrochemical series, Zn is above hydrogen
D) \[NO_{3}^{O-}\]is reduced in preference to hydronium ion.
Correct Answer: D
Solution :
Zinc gives \[{{H}_{2}}\]gas with dil. \[{{H}_{2}}S{{O}_{4}}/HCl\]but not with\[HN{{O}_{3}}\]because in\[HN{{O}_{3}},NO_{3}^{-}\]ion is reduced and gives \[NH_{4}^{+},{{N}_{2}}O,NO\]and\[N{{O}_{2}}\](based upon the concentration of\[HN{{O}_{3}}\]) \[[Zn+2HN{{O}_{3}}\xrightarrow{{}}\underset{(nearly\,6%)}{\mathop{Zn{{(N{{O}_{3}})}_{2}}}}\,+2H]\times 4\] \[HN{{O}_{3}}+8H\xrightarrow{{}}N{{H}_{3}}+3{{H}_{2}}O\] \[N{{H}_{3}}+HN{{O}_{3}}\xrightarrow{{}}N{{H}_{4}}N{{O}_{3}}\] \[4Zn+10HN{{O}_{3}}\xrightarrow{{}}\] \[4Zn(N{{O}_{3}})+N{{H}_{4}}N{{O}_{3}}+3{{H}_{2}}O\] Zn is on the top position of hydrogen in electro- chemical series. So Zn displaces \[{{H}_{2}}\]from dilute \[{{H}_{2}}S{{O}_{4}}\]and HCl with liberation of \[{{H}_{2}}.\]
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