Question

Cu + AgNO3 ---> Ag + Cu(NO3)2 Why is there a two after NO3? Thanks.

Answer 1

The valence of Cu is +2. The valence of the nitrate ion (NO3^-) is -1. For the compound to be zero, the Cu is +2, two nitrates give -2 (at -1 each), +2 and -2 = 0. Thus, one needs two nitrates to equal the charge on one Cu.

Answer 2

There is a 2 after the NO3 because 2 is for O and 3 is for Nitrate and Oxygen so its N3 O3+2=5 so it would be O5

Answer 3

just realized this was in 2009 they have prob already graduated and living a chemistry stress-free life :/