In: Chemistry
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The reaction is
2CH4(g) + O2(g) + 4Cl2(g) ---> 2CO(g) + 8HCl(g)
So as per the stoichiometry of given equation , 2 moles of methane will react with one mole of O2 and four moles of chlorine molecule to give 8 moles of HCl
Given : oxygen is in excess [so it will not limit the yield of reaction]
Let us calculate moles of methane and Cl2 present
Moles = Mass / molecular weight
(i) 46.0 g CH4, mol wt of CH4 = 12 + 4 = 16 g / mole
Moles of methane = 46 / 16 = 2.875 moles
for these moles of methane , moles of Cl2 required = 2X 2.875 = 5.75 moles
(ii) 131 g Cl2 , molwt of Cl2 = 2 X 35. 5 = 71 g / mole
Moles of Cl2 = 131 / 71 = 1.845 moles
so the limiting reagent is Cl2
now again
4 moles of Cl2 will react with 2 moles of CH4 to give 8 moles of HCl
1 mole of Cl2 will react with 0.5 moles of CH4 to give 2 moles of HCl
1.845 moles of Cl2 will react with 0.9225 moles of CH4 to give 2 X 1.845 moles of Hcl
Moles of HCl produced = 3.69 moles
Mass of HCl produced = Moles X molecular weight = 3.69 X 36.5 = 134.685 grams of HCl