CH(4-X)Br(X) 4-X de la H si X de l Br se scriu ca indici
MCH4-XBrX = 12 + (4 –x) + x*80 = (16 + 79x) g produs
(16 + 79x) g produs………………………………80x g Br
100 g produs…………………………………….84,21 g Br
(16 + 79x)*84,21 = 100*80x
16*84,21 +79x*84,21 = 8000x
1347,36 =8000x – 6652,59x
1347,36 = 1347,41x
x = 1 deci CH3Br (D)
CH4 + Br2 => CH3Br + HBr