Balance this
C3H3N + O2 ⇒ C + H2O + N2

4C₃H₃N   +    3O₂    →   12C  +   6H₂O    +     2N₂

Explanation:

The given reaction equation is expressed as:

        C₃H₃N   +    O₂    →   C  +   H₂O    +     N₂

The problem here entails balancing of the chemical reaction.

 So;

assign letters a,b,c,d and e as coefficients that will balance the expression:

            aC₃H₃N   +    bO₂    →   cC  +   dH₂O    +     eN₂

Conserving C :  3a  = c

                   H :   3a  = 2d

                   N :    a = 2e

                   O:    2b  = d

let a  = 1, c  = 3, e  =  , d  =  , b  =  

    Multiply through by 4;

          a  = 4, b  = 3, c  = 12 , d  = 6 and e  = 2

                4C₃H₃N   +    3O₂    →   12C  +   6H₂O    +     2N₂