Chemistry 9701 · AS & A Level · Nitrogen and sulfur

Nitrogen and sulfur — practice question

Nitrogen and phosphorus are both elements in Group 15 of the Periodic Table.
(a(i))[2]

Identify one natural source and one man-made source of nitrogen oxides in the atmosphere.

(a(ii))[1]

Write an equation to show the direct part played by $\text{NO}_2$ in forming acid rain.

(a(iii))[1]

Peroxyacetyl nitrate, PAN, is a constituent of photochemical smog. Describe how PAN forms from $\text{NO}_2$.

(a(iv))[1]

Nitric acid reacts with basic oxides to make nitrates. Write an equation for the reaction of nitric acid with calcium oxide.

(a(v))[1]

Describe the observation when solid calcium nitrate is heated strongly.

(b(i))[1]

Deduce the oxidation state shown by nitrogen in $\text{NO}_3^-$.

(b(ii))[1]

Identify the species oxidised in equation 1. Equation 1: $3\text{NO}_3^- + 8\text{Al} + 5\text{OH}^- + 18\text{H}_2\text{O} \rightarrow 3\text{NH}_3 + 8[\text{Al(OH)}_4]^- $

(b(iii))[1]

$\text{NH}_3$ is a basic gas. Describe how $\text{NH}_3$ is able to act as a base.

(b(iv))[1]

Suggest the shape of the $\left[\text{Al(OH)}_4\right]^-$ ion.

(c(i))[1]

Fig. 3.1 shows a sketch of some of the ionisation energies of phosphorus, $\text{P}$. Construct an equation for the third ionisation energy of $\text{P}$.

(c(ii))[2]

Complete the graph in Fig. 3.1 to show the third to sixth ionisation energies of $\text{P}$.

(d)[2]

Complete Table 3.1 with the properties of nitrogen and phosphorus in their standard states.

(e)[1]

A form of solid nitrogen has a lattice structure similar to solid iodine. Identify the lattice type of solid nitrogen.

(f(i))[2]

At very high temperatures, phosphorus can form $\text{P}_2$ molecules. $\text{P}_2$ contains a triple bond, $\text{P} \equiv \text{P}$. Describe the formation of the $\text{P} \equiv \text{P}$ bond in terms of orbital overlap.

(f(ii))[1]

The bond energy of $\text{P} \equiv \text{P}$ is $485\,\text{kJ mol}^{-1}$. The bond energy of $\text{N} \equiv \text{N}$ is $944\,\text{kJ mol}^{-1}$. Compare the reactivity of $\text{P}_2$ and $\text{N}_2$. Explain your answer.

Worked solution & mark scheme

This 19-mark question has a full step-by-step worked solution and mark scheme. One marking point: Natural source is lightning

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI