Nitrogen compounds — Chemistry 9701 AS & A Level Question & Worked Solution

(a(i))

Write the equation for a reaction in which ethylamine, $\text{C}_2\text{H}_5\text{NH}_2$, functions as a Brønsted-Lowry base.

(a(ii))

Ammonia, ethylamine and phenylamine, $\text{C}_6\text{H}_5\text{NH}_2$, are three nitrogen-containing bases. Arrange them in descending basicity, with the strongest base first.

(a(iii))[4]

Explain the reasoning behind the order you chose for the three compounds.

(b(i))

Write an equation for a reaction in which phenol, $\text{C}_6\text{H}_5\text{OH}$, behaves as a Brønsted-Lowry acid.

(b(ii))

Suggest why the $pK_a$ values of phenol and nitrophenol are different.

(b(iii))

Using the information in the table, predict which of the following $pK_a$ values is the most likely for the 4-nitrophenylammonium ion. Put a tick (✓) in the box next to your chosen value.

(b(iv))[5]

Explain the reason for your answer to part (iii).

(c(i))

Suggest which species intermediate $B$ is by drawing its structure in the box above.

(c(ii))[5]

Suggest suitable reagents and conditions for the three steps in the scheme above.

Nitrogen compounds — practice question

Worked solution & mark scheme