How would you balance Cu + HNO3 --> Cu(NO3)2?

Question

Can you also include how you did it?

Answer 1

The hydrogen disappeared in the equation...

Cu + 2HNO3 --> Cu(NO3)2 + H2

I first see if the Cu is balanced, since it is first on the reactant side of the equation and just out of preference. I see that it is already balance, one Cu on each side, so I move on and leave everything as it is. I go to NO3. I leave hydrogen for last, since it is a diatomic and things can get messy. There is one NO3 on the left, while there are two on the right. It isn't balanced, so I put a 2 in front of HNO3, balancing the NO3. Since you didn't put a hydrogen in the product side, I am assuming that it is a + H2 (Since hydrogen is a diatomic. H alone does not exist.) at the end of the equation. So now we check for the hydrogen. There are two hydrogen on the left side, and there are two on the right side. The hydrogen is balanced, making the whole equation balanced.

Hope this helps!

Answer 2

Cu No3 2 Hno3

Answer 3

Cu + 2HNO3 --> Cu(NO3)2 + H2 (g)

Answer 4

Half reactions:

Cu ===> Cu++ + 2e-

2H+ + 2HNO3 + 2e- ===> 2NO2 + 2H2O
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Cu + 4HNO3 ===> Cu(NO3)2 + 2NO2 + 2H2O

So much for A-level chemistry.