In: Chemistry
For the following reaction, 2.44 grams of methane (CH4) are allowed to react with 26.7 grams of carbon tetrachloride.
methane (CH4) (g) + carbon tetrachloride (g) ---> dichloromethane (CH2Cl2) (g)
What is the maximum amount of dichloromethane (CH2Cl2) that can be formed? in grams
What is the formula for the limiting reagent?
What amount of the excess reagent remains after the reaction is complete? in grams
1)
Molar mass of CH4,
MM = 1*MM(C) + 4*MM(H)
= 1*12.01 + 4*1.008
= 16.042 g/mol
mass(CH4)= 2.44 g
number of mol of CH4,
n = mass of CH4/molar mass of CH4
=(2.44 g)/(16.042 g/mol)
= 0.1521 mol
Molar mass of CCl4,
MM = 1*MM(C) + 4*MM(Cl)
= 1*12.01 + 4*35.45
= 153.81 g/mol
mass(CCl4)= 26.7 g
number of mol of CCl4,
n = mass of CCl4/molar mass of CCl4
=(26.7 g)/(153.81 g/mol)
= 0.1736 mol
Balanced chemical equation is:
CH4 + CCl4 ---> 2 CH2Cl2
1 mol of CH4 reacts with 1 mol of CCl4
for 0.152101 mol of CH4, 0.152101 mol of CCl4 is required
But we have 0.173591 mol of CCl4
so, CH4 is limiting reagent
we will use CH4 in further calculation
Molar mass of CH2Cl2,
MM = 1*MM(C) + 2*MM(H) + 2*MM(Cl)
= 1*12.01 + 2*1.008 + 2*35.45
= 84.926 g/mol
According to balanced equation
mol of CH2Cl2 formed = (2/1)* moles of CH4
= (2/1)*0.152101
= 0.304201 mol
mass of CH2Cl2 = number of mol * molar mass
= 0.3042*84.93
= 25.83 g
Answer: 25.8 g
2)
CH4 is limiting reagent
3)
According to balanced equation
mol of CCl4 reacted = (1/1)* moles of CH4
= (1/1)*0.152101
= 0.152101 mol
mol of CCl4 remaining = mol initially present - mol reacted
mol of CCl4 remaining = 0.173591 - 0.152101
mol of CCl4 remaining = 0.02149 mol
Molar mass of CCl4,
MM = 1*MM(C) + 4*MM(Cl)
= 1*12.01 + 4*35.45
= 153.81 g/mol
mass of CCl4,
m = number of mol * molar mass
= 2.149*10^-2 mol * 153.81 g/mol
= 3.305 g
Answer: 3.31 g