Question

balance the equation :- Cu + HNO3 = Cu(NO3)2 + NO H2O

Answer 1

Dear student!

In case of ,

Cu + HNO₃ -> Cu(NO₃)₂ + NO₂ + H₂O

Here, Cu is in 0 oxidation state which oxidizes to +2 in Cu(NO₃)₂ while N exists in +5 O.S in HNO₃ and reduced to +4 in NO₂ the reaction involved is:

Cu + 2e^- -> Cu⁺²

Similarly, N⁺⁵ ->N⁺⁴ + 1e^-

Now the no. of electrons is balanced as :

[Cu⁰ ->Cu⁺² + 2e^- ] x1

[N⁺⁵ + 1e^- -> N⁺⁴]x2

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Cu + 2 N⁺⁵ -> Cu⁺² + 2N⁺⁴

Putting the values in molecular form as:

Cu + 2HNO₃ -> Cu(NO₃)₂ + 2NO₂

Now, rest molecules are adjusted and filled as; Cu + 2HNO₃ -> Cu(NO₃)₂ + 2NO₂ +H₂O

Further the no. of atoms are balanced genuinely as ;

Cu + 4HNO₃ -> Cu(NO₃)₂ + 2NO₂ + 2H₂O