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

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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