KI + Cl2 ---> KCl + I2
Balance the single replacement chemical reaction.

2KI   +  Cl₂   →   2KCl     +    I₂

Explanation:

The reaction equation is given as:

        KI   +  Cl₂   →    KCl     +    I₂

The problem at hand is to balance this chemical reaction. To solve this problem we use a mathematical approach;

        aKI   +  bCl₂   →    cKCl     +    dI₂

 Conserving K : a = c

                     I :  a  = 2d

                   Cl : 2b = c  

 Now let a = 1, c  = 1 , d  = , b   = , ;

   Multiply through by 2;

             a  = 2, b = 1 , c = 2, d  = 1

            2KI   +  Cl₂   →   2KCl     +    I₂

What reverses the direction of electric current in the armature coil of D.C. motor? ... The split ring is arranged so that each half of the commutator changes brushes just as the coil reaches the vertical position. Changing brushes reverse the current in the loop.

Explanation: