Answer:
Cu(NO₃)₂ (aq) + 2 KI (aq) ---> CuI₂ (s) + 2 KNO₃
Step-by-step explanation:
When writing the reaction with the symbols, you need to take into account the charges of the ions. If he charges on the ions do not balance out in a molecule, they need to be made up for in the form of subscripts. For example, copper (+2) and iodine (-1) have charges which do not balance. Thus, to make the molecule neutral, you need to have two iodine atoms (CuI₂).
The unbalanced equation:
Cu(NO₃)₂ (aq) + KI (aq) ---> CuI₂ (s) + KNO₃
Reactants: 1 copper, 2 nitrate, 1 potassium, 1 iodine
Products: 1 copper, 1 nitrate, 1 potassium, 2 iodine
The balanced equation:
1 Cu(NO₃)₂ (aq) + 2 KI (aq) ---> 1 CuI₂ (s) + 2 KNO₃
Reactants: 1 copper, 2 nitrate, 2 potassium, 2 iodine
Products: 1 copper, 2 nitrate, 2 potassium, 2 iodine