Answer to Question #188077 in General Chemistry for Jeva nae Castro

Question

Methanol (ch3oh), also called methyl alcohol, is the simplest alcohol. it is used as a fuel in race cars and is a potential replacement for gasoline. methanol can be manufactured by combination of gaseous carbon monoxide and hydrogen. suppose 68.5 kg co(g) is reacted with 8.60 kg h2(g). calculate the theoretical yield of methanol. if 3.57 × 104 g ch3oh is actually produced, what is the percent yield of methanol?

Answer 1

Step 1: Convert Kg into g

68.5 Kg CO = 68500 g CO

8.60 Kg H₂ = 8600 g

Step 2: Find out Limiting reactant;

The Balance Chemical Equation is as follow;

                 CO + 2 H₂  →  CH₃OH

According to Equation,

          28 g (1 mol) CO reacts with = 4 g (2 mol) of H₂

So,

          68500 g CO will react with = X g of H₂

Solving for X,

           X = (68500 g × 4 g) ÷ 28 g

           X  = 9785 g of H₂

It shows 9785 g H₂ is required to react with 68500 g of CO but we are provided with 8600 g of H₂ which is less than required. Therefore, H₂ is provided in less amount hence, it is a Limiting reagent and will control the yield of products.

Step 3: Calculate Theoretical Yield

According to equation,

      4 g (2 mol) H₂ reacts to produce = 32 g (1 mol) Methanol

So,

             8600 g H₂ will produce = X g of CH₃OH

Solving for X,

           X  = (8600 g × 32 g) ÷ 4 g

           X = 68800 g of CH₃OH

Step 4: Calculate %age Yield

           %age Yield = Actual Yield ÷ Theoretical Yield × 100

Putting Values,

           %age Yield = 3.54 × 10⁴ g ÷ 68800 g × 100 = 51.45 %

Hence the percent yield of methanol is 51.45%