Question

Two moles of a hydrocarbon CnH2n burns in 'M' moles of O2 to produce 10moles of H2O as one of the products. Find 'M'

Answer 1

On burning hydrocarbon in oxygen we get H2O . 1mole H2O is obtained when 1/2 mole O2 is consumed during burning. So to get 10 moles of water consumption of oxygen will be 5 moles. Hence M=5 moles.