How do i do this question please help me

3

Explanation:

The reaction is given as:

           H₂S   +   O₂   →  SO₂    +    H₂O

Let us balance the chemical equation.

 We take some letters and we use them as the coefficient to balance the equation;

          aH₂S   +   bO₂   →  cSO₂    +    dH₂O

Now,

  Conserving H;

         2a  = 2d

 Conserving S;

         a = c

 Conserving O;

        2b  = 2c + d  

Let a  = 1, d  = 1, c  = 1, b  =  and multiply through by 2;

    a = 2, b  = 3, c  = 2 and d = 2

So, the balanced reaction equation is given as;

    2H₂S   +   3O₂   →  2SO₂    +    2H₂O