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

(a(i))

Write the equation for a reaction where ethylamine, $\text{C}_2\text{H}_5\text{NH}_2$, behaves 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 these three substances in order of basicity, starting with the strongest base.

(a(iii))[4]

Explain why you placed the three compounds in this order.

(b(i))

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

(b(ii))

Suggest an explanation for the difference between the $pK_a$ values of phenol and nitrophenol.

(b(iii))

Using the information in the table opposite, predict which of the following $pK_a$ values is the most likely for the 4-nitrophenylammonium ion. Put a tick ($\checkmark$) in the box next to the value you select.

(b(iv))[5]

Explain your answer to part (iii).

(c(i))

Suggest the identity of intermediate $\text{B}$ by drawing its structure in the box provided.

(c(ii))[5]

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

Nitrogen compounds — practice question

Worked solution & mark scheme