Which formula corresponds to Iron (II) Nitrate?

Which formula corresponds to Iron (II) Nitrate?

• A. Fe(NO3)2
• B. FeNO3
• C. Fe(NO3)3
• D. Fe2(NO3)3

Answer: (A)

Balancing charges in ionic compounds is the key idea. Iron in Iron(II) Nitrate has a +2 charge. Each nitrate ion carries a -1 charge. To make a neutral salt, you need two nitrate ions to balance the +2 from iron, giving Fe(NO3)2. The parentheses show the NO3 group, and the 2 outside means two of them. Other formulas don’t balance charges correctly: FeNO3 would not balance the charges properly, Fe(NO3)3 would imply iron in the +3 state, and Fe2(NO3)3 would leave the overall formula with an unequal, non-neutral charge. So Fe(NO3)2 is the correct representation.

Balancing charges in ionic compounds is the key idea. Iron in Iron(II) Nitrate has a +2 charge. Each nitrate ion carries a -1 charge. To make a neutral salt, you need two nitrate ions to balance the +2 from iron, giving Fe(NO3)2. The parentheses show the NO3 group, and the 2 outside means two of them. Other formulas don’t balance charges correctly: FeNO3 would not balance the charges properly, Fe(NO3)3 would imply iron in the +3 state, and Fe2(NO3)3 would leave the overall formula with an unequal, non-neutral charge. So Fe(NO3)2 is the correct representation.