neutrilization reaction

Question

Fe(OH)3 + 3HNO3 > Fe(NO3)3 + 3H2O

 

in the product why  is the NO in parenthesis with a 3 in it and why does it have a subscript of 3

Answer 1

Realize that the NO3 anion (the nitrate ion) has a -1 charge.  Thus, when combined with a Fe ion that has a +3 charge, it takes 3 of them to accommodate the the +3 charge.  Note, it isn't the NO in parentheses, but rather it is the NO3 in parentheses.