Here's the solution for .95.
.95: Mass of Chloromethane Produced
The balanced chemical equation for the reaction is:
CH4(g)+Cl2(g)⟶CH3Cl(g)+HCl(g)
Given:
- Mass of CH4=20.5 g
- Mass of Cl2=45.0 g
- Percent yield = 75.0%
Step 1: Calculate the molar masses of CH4, Cl2, and CH3Cl.
- Molar mass of CH4=12.01g/mol(C)+(4×1.008g/mol(H))=16.042 g/mol
- Molar mass of Cl2=2×35.45g/mol(Cl)=70.90 g/mol
- Molar mass of CH3Cl=12.01g/mol(C)+(3×1.008g/mol(H))+35.45g/mol(Cl)=50.484 g/mol
Step 2: Calculate the moles of each reactant.
molesofCH4=16.042g/mol20.5g=1.2779mol
molesofCl2=70.90g/mol45.0g=0.63469mol
Step 3: Determine the limiting reactant.
From the balanced equation, 1molofCH4 reacts with 1molofCl2.
To react all 1.2779molofCH4, we would need 1.2779molofCl2.
Since we only have 0.63469molofCl2, chlorine (Cl2) is the limiting reactant.
Step 4: Calculate the theoretical moles of CH3Cl produced from the limiting reactant.
From the balanced equation, 1molofCl2 produces 1molofCH3Cl.
theoreticalmolesofCH3Cl=0.63469molCl2×1molCl21molCH3Cl=0.63469molCH3Cl
Step 5: Calculate the theoretical mass (yield) of CH3Cl.
theoreticalmassofCH3Cl=0.63469mol×50.484g/mol=32.049g
Step 6: Calculate the actual mass of CH3Cl using the given percent yield.
ActualYield=TheoreticalYield×100%PercentYield
ActualYield=32.049g×100%75.0%=32.049g×0.750=24.03675g
Rounding to three significant figures:
24.0 g
3 done, 2 left today. You're making progress.