An amino acid contains 52.2% carbon, 9.3% hydrogen, 8.7% nitrogen and 29.8% oxygen by mass and has a relative molecular mass of 161 g/mol. What is its molecular formula? What functional groups must it have?
In 100g of compound, the amount of each element is given by: C: n = 52.2/12 = 4.35 H: n = 9.3/1 = 9.3 N: n = 8.7/14 = 0.621... O: n = 29.8/16 = 1.8625 Dividing through by the smallest amount (0.621) gives: C: 7.0048..., H: 14.9758..., N: 1, O: 2.9991... These are all very close to whole numbers so the empirical formula is C7H15NO3. This has a relative formula mass of 161 so the molecular formula is also C7H15NO3. As this compound is stated to be an amino acid it must contain both an amine and a carboxylic acid group.
GB
Related Chemistry A Level answers
All answers ▸What is the effect of temperature on K(equilibrium constant)?
pH and Kw question: A student dissolves 1.75g of a drain cleaner (based on NaOH) in water and makes the solution up to 100cm3. The student measures the solution pH as 13.60. Determine the percentage of NaOH in the drain cleaner, in terms of mass (g).
A) What assumptions are made about ideal gases. B) if 14g of an ideal gas is added to a 4 dm3 container at 210Kpa pressure and a temperature of 40oc how many moles were added and suggest the identity of the gas.
Explain the reactions of CH3CH2Cl with the nucleophile NH3 and name the initial product formed.