Penicillin. an important antibiotic (antibacterial agent), was discovered accidentally by the scottish bacteriologist alexander fleming in 1928, although he was never able to isolate it as a pure compound. this and similar antibiotics have saved millions of lives that would otherwise have been lost to infections. penicillin, like many of the molecules produced by living systems, is a large molecule containing many atoms. one type of penicillin, penicillin f, has the formula c14h20n2so4. compute the mass percent of each element in this compound.

mass percent of carbon       = 57.78 %

mass percent of hydrogen   = 6.40 %

mass percent of nitrogen    = 8.96 %

mass percent of oxygen    = 20.49 %

mass percent of sulfur     =  10.24 %

Explanation:

Given data

Molecular formula = C₁₄H₂₀N₂O₄S

molecular mass (total mass) = 312.39 g/mol

Percentage of carbon = ?

Percentage of hydrogen = ?

Percentage of oxygen = ?

Percentage of nitrogen = ?

Percentage of sulfur = ?

Solution

1st we find out number of moles of each element from the molecular formula

  Number of moles of carbon  = 14 mol

  Number of moles of hydrogen   = 20 mol

  Number of moles of nitrogen   = 2 mol

  Number of moles of oxygen  = 4 mol

  Number of moles of sulfur   = 1 mol

Now we find out the mass of each element

as we know that

     mass = number of moles × molecular mass

 mass of carbon  = 14 mol × 12 g/mol

 mass of carbon  = 168 g

 mass of hydrogen   = 20 mol × 1 g/mol

 mass of hydrogen   = 20 g

 mass of nitrogen   = 2 mol × 14 g/mol

 mass of nitrogen   = 28 g

 mass of oxygen  = 4 mol × 16 g/mol

 mass of oxygen  = 64 g

 mass of sulfur   = 1 mol × 32 g/mol

 mass of sulfur   =  32 g

now we find out the mass percent of each element

        mass percent = ( mass ÷ total mass ) × 100

 mass percent of carbon  = ( 168 g ÷ 312.39 g/mol ) × 100

 mass percent of carbon  = 57.78 %

 mass percent of hydrogen   = ( 20 g ÷ 312.39 g/mol ) × 100

 mass percent of hydrogen   = 6.40 %

 mass percent of nitrogen   = ( 28 g ÷ 312.39 g/mol ) × 100

 mass percent of nitrogen   = 8.96 %

 mass of oxygen  =( 64 g ÷ 312.39 g/mol ) × 100

 mass percent of oxygen  = 20.49 %

 mass percent of sulfur   = ( 32 g ÷ 312.39 g/mol ) × 100

 mass percent of sulfur   =  10.24 %