Question
10. Phenyl magnesium bromide is used as a Grighard reagent is organic synthesis. Determine its empirical and molecular formula if its mouler mans is 181.319 ginool and it contains 39.7458% c. 2.77956% 13.4059% Mr. and 4600919686
Solution
4.2
(208 Votos)
Olivia Maria
Profissional · Tutor por 6 anos
Resposta
To determine the empirical and molecular formula of phenyl magnesium bromide, we need to follow these steps:1. Calculate the percentage composition of each element in the compound.2. Convert the percentage composition to grams.3. Determine the simplest whole number ratio of the elements.4. Write the empirical formula based on the simplest whole number ratio.5. Calculate the molar mass of the empirical formula.6. Determine the molecular formula based on the given molar mass.Given information:- Molar mass of phenyl magnesium bromide: 181.319 g/mol- Percentage composition: C: 39.7458%, H: 2.77956%, Br: 13.4059%, Mg: 43.8886%Step 1: Calculate the percentage composition of each element in the compound.Percentage composition:- C: 39.7458%- H: 2.77956%- Br: 13.4059%- Mg: 43.8886%Step 2: Convert the percentage composition to grams.Assume we have 100 g of the compound.- C: 39.7458 g- H: 2.77956 g- Br: 13.4059 g- Mg: 43.8886 gStep 3: Determine the simplest whole number ratio of the elements.Divide each mass by the smallest mass (H: 2.77956 g) to get the simplest whole number ratio.- C: 39.7458 g / 2.77956 g = 14.29- H: 2.77956 g / 2.77956 g = 1- Br: 13.4059 g / 2.77956 g = 4.83- Mg: 43.8886 g / 2.77956 g = 15.83The simplest whole number ratio is approximately 14:1:5:16.Step 4: Write the empirical formula based on the simplest whole number ratio.Empirical formula: C14HBr5MgStep 5: Calculate the molar mass of the empirical formula.Molar mass of C14HBr5Mg = (14 × 12.01) + (1 × 1.008) + (5 × 79.904) + (1 × 24.305) = 341.36 g/molStep 6: Determine the molecular formula based on the given molar mass.Given molar mass of phenyl magnesium bromide: 181.319 g/molMolecular formula: (C14HBr5Mg)2 = C28H2Br10Mg2Therefore, the empirical formula of phenyl magnesium bromide is C14HBr5Mg, and the molecular formula is C28H2Br10Mg2.