GUYS I NEED HELP WITH THIS ASSIGNMENT MY LAST ASSIGNMENT FOR THE DAY

1. What are the reactants? What are the products? Use the reaction below (2pts) 

Na   +   Cl2     →   NaCl
 
2. Why do chemical reactions need to be balanced? (2pt) 
 
3. In order to balance the following reaction, I need to add more Chlorine atoms to the product side. Would the highlighted answer be a correct way of adding more Chlorine atoms? Why or why not? (2pt) 
Balanced:   Na   +   Cl2     →   NaCl2         
 
4. Given the following reactions, what does the coefficient 2 represent for 2KI? (2pt)
           Cl2   +   2 KI  →    2 KCl   +  I2