Question

Cu + HNO3 ---> Cu(NO3)2 + H2O + NO

Balance the Equation

Answer 1

Firstly try to balance N on both sides as follows:

Cu + 3HNO₃ ---> Cu(NO₃)₂ + H₂O + NO

Since hydrogen is unbalanced try to balance hydrogen then

Cu + 4HNO₃ ---> Cu(NO₃)₂ + 2H₂O + NO

Again N atom is unbalanced try to balance it:

Cu + 4HNO₃ ---> Cu(NO₃)₂ + 2H₂O + 2 NO

now oxygen is unbalanced try to balance it again

Cu + 4HNO₃ ---> Cu(NO₃)₂ + 4 H₂O + 2 NO

Oxygen is balanced now but hydrogen seems to be unbalanced try that again:

Cu + 8 HNO₃ ---> Cu(NO₃)₂ + 4 H₂O + 2 NO

now nitrogen is balanced it can be done by following way:

Cu + 8 HNO₃ ---> 3 Cu(NO₃)₂ + 4 H₂O + 2 NO

Except copper everything is balanced

3 Cu + 8 HNO₃ ---> 3 Cu(NO₃)₂ + 4 H₂O + 2 NO

Reaction is balanced now !