Questions 1
(a) Topic – 9.1 Periodicity of physical properties of the elements in Period 3
(b) Topic – 9.1 Periodicity of physical properties of the elements in Period 3
(c) Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
(d) Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
(e) Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
Bismuth is an element in Group 15 of the Periodic Table.
(a) Bismuth has metallic bonding. Draw a labelled diagram to show the metallic bonding in bismuth.
(b) Bismuth reduces water to form bismuth oxide, Bi₂O₃. A colourless gas that ignites with a squeaky pop also forms.
(i) Construct an equation for the reduction of water by bismuth.
(ii) Bi₂O₃ is a yellow insoluble solid that melts at 1090K. The molten compound conducts electricity. Deduce the structure and bonding of Bi₂O₃. Explain your answer.
(c) Bi₂O₃ can be used to form NaBiO₃, as shown in equation 1.
equation 1 Na₂O + Bi₂O₃ + O₂ → 2NaBiO₃
(i) Deduce the oxidation number of Bi in Bi₂O₃ and in NaBiO₃.
oxidation number of Bi:
in Bi₂O₃ …………………………………………. in NaBiO₃ …………………………………………………..
(ii) Identify the reducing agent in equation 1.
(d) \(NaBiO_3\) is an oxidising agent with similar properties to KMnO₄. Fig. 1.1 shows an example of the use of NaBiO₃ as an oxidising agent.
(i) Explain the term oxidising agent.
(ii) Compound X forms when methylbut-2-ene reacts with \(KMnO_4\). State the essential conditions for this reaction.
(iii) Complete Table 1.1 to show what is observed when compounds Y and Z react separately with the named reagents.
(iv) Construct an equation for the reaction of Z with \(NaBH_4\). Use [H] to represent an atom of hydrogen from the reducing agent.
(e) NaBiO₃ can be used to determine the concentration of Mn²⁺(aq). The ionic equation for the reaction is shown in equation 2.
equation 2 \(2Mn^{2+} + 5BiO_3^– + 14H^+ \to 2MnO_4^– + 5Bi^{3+} + 7H_2O\)
A student uses the following procedure in an experiment.
• Add 100.0 cm³ of a saturated solution of Mn²⁺(aq) to a volumetric flask.
• Add distilled water to the flask to make a 1.00 dm³ diluted solution.
• Titrate a 25.00 cm³ sample of the diluted solution with 0.100 moldm⁻³ NaBiO₃ (aq).
The 25.00 cm³ sample of the diluted solution of Mn²⁺(aq) reacts completely with exactly 21.50 cm³ of 0.100 moldm⁻³ NaBiO₃(aq). Calculate the concentration, in mol/dm³, of Mn²⁺(aq) in the saturated solution. Show your working.
▶️Answer/Explanation
Ans:
(b)(i) \(2Bi + 3H_2O \to Bi_2O_3 + 3H_2\)
(ii) giant AND has a high melting point
ionic AND conducts electricity (only) when molten
(c)(i) Bi₂O₃ (+)3 / III AND NaBiO₃ (+)5 / V
(ii) Bi₂O₃
(d)(i) a substance that removes electrons from another / causes electron loss / gains electrons
(ii) (KMnO₄ is) cold and dilute
(iv) CH₃CHO + 2[H] → CH₃CH₂OH
(e) moles of NaBiO₃ = 21.50 / 1000 × 0.100 (= 2.15 × 10⁻³ mol)
moles of Mn²⁺ in dil. = 2.15 × 10⁻³ × 2 / 5 × 40 (= 0.0344 mol)
conc. saturated Mn²⁺ = 0.0344 × 1000 / 100 = 0.344 mol dm⁻³
Questions 2
(a)Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
(b)Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
(c)Topic – 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state)
(d) Topic- 13.1 Formulas, functional groups and the naming of organic compounds
Chlorine, Cl₂, reacts with many elements and compounds to form chlorides. Table 2.1 shows information about some chlorides of Period 3 elements.
(a) Complete Table 2.1.
(b) When Cl₂ reacts with cold NaOH(aq), Cl₂ is both oxidised and reduced. The products are NaCl, water, and G.
(i) State the type of redox reaction in which the same species is both oxidised and reduced.
(ii) Identify G.
(iii) Write an equation for the reaction between Cl₂ and hot NaOH(aq).
(iv) Describe fully what is observed when AgNO₃ (aq) is added to the aqueous solution of the chloride of sodium, followed by dilute NH₃ (aq).
(c) An excess of Cl₂ reacts with phosphorus to form PCl₅.
(i)PCl₅ is a simple molecule in the gas phase. It also exists in a solid form as two ions, PCl₄⁺ and PCl₆⁻. Complete Table 2.2 to identify the shapes of each of these species.
(ii) PCl₅ reacts with J to form H₃PO₄. Identify J and state the type of reaction.
J …………………………… type of reaction …………………………………..
(d) Cl₂ reacts readily with propene to form K, 1,2-dichloropropane. K can be used to form L.
(i) Complete Fig. 2.2 to show the mechanism for the reaction of Cl₂ with propene in reaction 1. Include charges, dipoles, lone pairs of electrons and curly arrows, as appropriate. 
(ii) Identify the reagent and conditions for reaction 2.
(iii) Draw one repeat unit of the addition polymer that forms from L.
▶️Answer/Explanation
Ans:
(a)
(b)(i) disproportionation
(ii) NaClO / sodium chlorate(I)
(iii) 3Cl₂ + 6NaOH → NaClO₃ + 5NaCl + 3H₂O
(iv) white ppt / solid dissolves (in NH₃(aq))
(c)(i) ● trigonal bipyramidal ● octahedral
(ii) H₂O / water hydrolysis
(ii) NaOH in ethanol AND heat
Questions 3
(a) Topic – 5.1 Enthalpy change, ΔH
(b) Topic -13.1 Formulas, functional groups and the naming of organic compounds
(c)Topic -23.1 Lattice energy and Born-Haber cycles
(d) Topic- 3.4 Covalent bonding and coordinate (dative covalent) bonding
Nitrogen, \(N_2\), is generally an unreactive molecule but it does react under certain conditions.
(a) Give two reasons to explain the lack of reactivity of nitrogen
(b) \(N_2\) can react with oxygen in an internal combustion engine to form a mixture of NO and \(NO_2\). Fig. 3.1 shows a reaction scheme involving \(N_2\).
(i) Write an equation to show the formation of a mixture of NO and NO₂ in reaction 1.
(ii) Give the formulae of the products of reaction 2.
(iii) State one environmental consequence of reaction 3.
(c) The Haber process involves the reaction of N₂ and H₂ to form ammonia, NH₃. A catalyst is used, which allows the process to be carried out at a lower temperature and pressure.
(i) Use the information in (c) to complete Table 3.1. 
(ii) Explain how the presence of a catalyst affects the reaction.
(iii) State and explain the effect, if any, on the rate of the Haber process as the pressure is lowered.
(d) The N₂F₂ molecule has a double covalent bond between its nitrogen atoms. This consists of a σ and a π bond.
(i) Complete Fig. 3.2 to show the dot-and-cross diagram for N₂F₂. Show outer electrons only.
(ii) Deduce the hybridisation of the N atoms in N₂F₂.
(iii) Draw a diagram of the π bond between the N atoms in N₂F₂ and describe how it forms.
▶️Answer/Explanation
Ans:
(a) strong triple bond / high triple bond enthalpy
non-polar (molecule)
(b)(i) e.g. \(N_2 + 1½O_2 \to NO + NO_2\)
(ii) HNO₂ and HNO₃
(iii) photochemical smog
(c)(i) 0 for both \(\Delta H_f\) of \(N_2\) and \(H_2\)
–46 for \(\Delta H_f\) of NH3
(ii) increases rate by providing a different mechanism with a lower activation energy
(iii) rate is lowered
lower frequency of successful collisions / number of successful collisions per unit time
(ii) \(sp^2\)
Questions 4
(a)Topic -13.4 Isomerism: structural isomerism and stereoisomerism
(b)Topic-13.1 Formulas, functional groups and the naming of organic compounds
(c)Topic-13.1 Formulas, functional groups and the naming of organic compounds
Compound S is used in food flavourings. A possible synthesis of S is shown in Fig. 4.1.
(a) P, Q, R and S show stereoisomerism. Complete Table 4.1 by identifying with a tick the type of stereoisomerism that each molecule shows. The type of stereoisomerism shown by Q is given. 
(b) (i) Give the structural formula of Q.
(ii) Name the mechanism in reaction 2.
(iii) Complete the equation for reaction 3. R is represented as \(C_4H_9CN\).
\(C_4H_9CN\) + ………………………………………………..
(c) Compounds S and T react to form organic compound U, which has a single functional group.
(i) Use the data from Table 4.2 to show that U contains 7 carbon atoms. Show your working.
(ii) Fig. 4.2 shows the infrared spectrum of U.
Use Fig. 4.2 and Table 4.3 to identify the functional group present in U. Explain your answer fully.
functional group ……………………………………….
explanation ………………………………………………
(iii) T also has a single functional group. Use the information in (c)(i) and your answer to (c)(ii) to identify T and U. Draw the structures of T and U in the boxes.
▶️Answer/Explanation
Ans:
(iii) \(C_4H_9CN + 2H_2O + H^+ \to C_4H_9COOH + NH_4^+\)
(c)(i) n = 100 / 1.1 × 0.55 / 7.2
= 6.94 (so 7 carbon atoms)
(ii) FG = ester / (R)COOR(‘)
(absorption at) 1040–1300 cm⁻¹ indicates C—O (stretch)
AND (absorption at) 1710–1750 cm⁻¹ indicates (C=O stretch)
