Question

Consider the following reaction:

(7.8 g) (60% yield)

What is the mass of the organic product 'P' formed? [Atomic mass: C - 12 u, H - 1 u, O -16 u]

• A. 10.6 g
• B. 7.32 g
• C. 6.75 g
• D. 6.36 g

Answer 1

Answer: (D)

6.36 g

Answer 2

1. Identify the reaction: The reaction of benzene with carbon monoxide (CO) and hydrogen chloride (HCl) in the presence of anhydrous aluminum chloride (AlCl3) is the Gattermann-Koch reaction, which produces benzaldehyde.
2. Calculate moles of benzene:
   • Molar mass of benzene (C6H6) = (6 × 12) + (6 × 1) = 78 g/mol.
   • Given mass of benzene = 7.8 g.
   • Moles of benzene = Mass / Molar mass = 7.8 g / 78 g/mol = 0.1 mol.
3. Determine theoretical yield of benzaldehyde:
   • The reaction stoichiometry between benzene and benzaldehyde (C6H5CHO) is 1:1. Therefore, 0.1 mol of benzene will theoretically produce 0.1 mol of benzaldehyde.
   • Molar mass of benzaldehyde (C7H6O) = (7 × 12) + (6 × 1) + (1 × 16) = 84 + 6 + 16 = 106 g/mol.
   • Theoretical yield of benzaldehyde = Moles × Molar mass = 0.1 mol × 106 g/mol = 10.6 g.
4. Calculate actual yield:
   • The reaction yield is given as 60%.
   • Actual yield = Theoretical yield × (Percentage yield / 100)
   • Actual yield = 10.6 g × (60 / 100) = 10.6 g × 0.6 = 6.36 g.