The balanced equation is
CO(g) + 2H2 (g) -> CH3OH(l)
Which means, every 2 moles of H2 will react with 1 mole of CO.
Find the number of moles, n = m/Mr
CO = (1.5x10^-6)/(12) = 1.25 x 10^-7 mol
H2 = (6.8x10^-6)/(2) = 3.4 x 10^-6 mol
Since we have a mole ratio of 2 to 1, H2 value will be multipled by 2 as 2 moles of H2 react to 1 mole of CO.
3.4 x 10^-6 x 2 = 6.8 x 10^-6
So obviously we can see that H2 is in excess and only some H2 molecules will be left at the end of the reaction.
6.8 x 10^-6 - 1.25 x 10^-7 = 6.675 x 10^-6 Moles of unreacted H2
To find the molecules of this amount of moles, Multiply it by Avogadros number, 6.02 x 10^23
Because for every mole, there are 6.02 x 10^23 molecules
6.575 x 10^-6 x 6.02 x 10^23 = 3.96 x 10^ 18 Molecules of gas
