This page contains the AQA A2 Periodicity Questions and kerboodle answers for revision and understanding .This page also contains the link to the notes and video for the revision of this topic.
Banner 1
C22.1 Reactions of Period 3 elements AQA A2 Chemistry C22 Periodicity Kerboodle Answers: Page No. 94
1 They are malleable (can be beaten into sheets) and ductile (can be drawn inro wires). They aregood conductors of heat. 2 They tend to be brittle -they are poor conductors of heat. 3 a +1 b What is unusual about this? -1. Oxidation state of oxygen is usually -2. c C +2-2+1 Mg(OH)2 = + 2 + 2 (-2 + 1) = 0 4 +422.2 The oxides of elements in Period 3 AQA A2 Chemistry C22 Periodicity Kerboodle Answers : Page No. 98
1 Na2O(s) + H2O(1) — 2NaOH(aq) b i Before+1, after+1 ii Neither 2 a OH–ions b What range of pH values represents an alkaline solution? Greater than 7 3 Phosphorus forms another oxide, P 406. a Acidic22.3 The acidic/basic nature of the Period 3 oxides AQA A2 Chemistry C22 Periodicity Kerboodle Answers : Page No. 100
1 a Na2O(s) + 2HCI(aq) →2NaCI(aq) + H2O(1) b Magnesium oxide with sulfuric acid MgO(s) + H2SO4(aq) →MgSO4(aq) + H2O(1) c Aluminium oxide with nitric acid. AI2O3(s) + 6HNO3(aq) → 3H2O(I) + 2Al(NO3)3(aq) 2 a +4 -2 +1 -2 +1 +1 +4-2 +1 -2 SiO2(S) + 2NaOH(aq) → Na2SiO3(aq) + H2O(1) b Is the reaction a redox reaction? No c Explain your answer to b. No change in oxidation number of any of the elements occurs 3 P4Ol0(s) + 6H2O(1) →4H 3PO4(aq) Banner 2Practice questions: Page No. 101-103
1 (a) Charge on oxide ion bigger than on chloride or oxide ion smaller than chloride or charge density on oxide ion greater than chloride Therefore electrostatic attraction is stronger (b) MgO (is a white solid that) forms a suspension (or slightly soluble) MgO + H2O → Mg(OH)2 or → Mg2+ + 2OH pH is 8 to 10 (c) SO2 dissolves or forms (colourless) solution SO2 + H2O → H2SO3 or → H+ + H2SO3− or → 2H+ + SO32- pH is 1 to 4 2 Na2O: vigorous or exothermic reaction; or forms a colourless solution, pH of solution formed is 13 or 14. Na2O + H2O → 2NaOH P4O10 or P2O5: vigorous or exothermic reaction; or forms a colourless solution, pH of solution formed is 0 or 1. P4O10 + 6H2O → 4H3PO4 3 (a) (i) Ionic (ii) Sodium (iii) Na2O + H2O → 2NaOH (b) (i) Covalent (ii) Phosphorus (iii) H3PO4 (c) (i) Macromolecular (ii) Silicon (iii) e.g., CaO + SiO2 → CaSiO3 4 (a) (i) P4O10 or SO3 (ii) Na2O (b) (i) MgO and HNO3 MgO + 2HNO3 → Mg(NO3)2 + H2O (ii) SiO2 and NaOH 2NaOH + SiO2 → Na2SiO3 + H2O (iii) Na2O and H3PO4. (3 marks) 3Na2O + 2H3PO4 → 2Na3PO4 + 3H2O (c) P4O10 is molecular or simple covalent. This means that there are weak intermolecular forces between molecules. SiO2 is a macromolecule or giant covalent molecule. Many strong covalent bonds must be broken. 5 (a) Sodium oxide Na2O + H2O → 2NaOH pH = 14 (b) Sulfur dioxide. (2 marks) AQA, 2003 SO2 + H2O → H2SO3 pH = 1–3 6 (a) (i) P is Na2O or sodium oxide. Ionic Ions are not free to move in the solid state. Ions are free to move when molten or in aqueous solution. Na2O + H2O → 2NaOH (ii) Q is SO2 or sulfur dioxide. Covalent Intermolecular forces are weak or van der Waals forces are weak. SO2 + H2O → H2SO3 (b) (i) . Amphoteric (ii) . Al(OH)3 + NaOH → NaAl(OH)4 2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O (iii) Suggest why R is insoluble in water. (6 marks) AQA 2002- Large lattice energy;
- Strong covalent bonds;
- ΔHsoln is very positive;
- ΔG is very positive;
- The sum of the hydration energies is less than the covalent bond energies.
- Hard
- Brittle / not malleable
- Insoluble
- Non conductor