Question

In nitric acid 'cu' copper is oxidised by nitrate ion and not by hydrogen ion why ?

Answer 1

the above gives matal reactivity series here the right one cannot displace left ones . so here u can observe hydrgn is left of cu .so it is not oxidised .and if u want to know about ions u shld refer electro chemical series .... thanking u .hope it helps u

Answer 2

$Cu^{2+}$In nitric acid copper is oxidized by nitrate ion and not by hydrogen ions.

Explanation:

• Oxidation (of an atom or ion) is indicated by an increase in the oxidation number and a decrease is indicated by a decrease in the oxidation number.
• There are actually four $HNO_{3}$ on the reactant side.
• Four $H^{+}$ ions are shown and only two of the four $NO_{3} ^{-}$ ions are shown.
• But look at the product side. $Cu^{2+}$ ions do not have negatively charged counter ions! $Cu^{2+}$ should also have two $NO_{3} ^{-}$ because it is copper nitrate.
• Thus two $NO_{3}^{-}$ ions are missing on both sides.
• They have not changed their oxidation states.
• Add them up, and you have nothing more.