In: Chemistry
18.7 g of aluminum and 226 g of chlorine gas react until all of the aluminum metal has been converted to AlCl3. The balanced equation for the reaction is the following. 2 Al(s) + 3 Cl2(g) → 2 AlCl3(s) What is the quantity of chlorine gas left, in grams, after the reaction has occurred, assuming that the reaction goes to completion? (The formula mass of aluminum metal, Al, is 26.98 g/mol, and the formula mass of chlorine gas, Cl2, is 70.90 g/mol.)
2 Al(s) + 3 Cl2(g) → 2 AlCl3(s)
no of moles of Al = W/G.A.Wt
= 18.7/27 = 0.69 moles
no of moles of Cl2 = W/G.A.Wt
= 226/71 = 3.183moles
2moles of Al react with 3 moles of Cl2
0.69 moles of Al react with = 3*0.69/2 = 1.035 moles of Cl2
Cl2 is exess reactant
the moles of chlorine gas left after complete the reaction = 3.183-1.035 = 2.148 moles
the quantity of chlorine gas left, in grams, after the reaction has occurred, = no of moles * gram molar mass
= 2.148*71 = 152.5g