Eduqas A-Level Chemistry (A410)
A-Level Chemistry
Answer sheet
Inorganic chemistry
Separate mark scheme — do not issue with the student worksheet
Time guide: — · Questions: 32 · Total marks: 104
Written in Eduqas A-Level style. Show working and include units.
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
1. State what is meant by periodicity.
[1 mark]
- repeating trends across a period
2. State what is meant by first ionisation energy.
[1 mark]
- energy to remove 1 mol of electrons from 1 mol of gaseous atoms
3. State what is meant by Group 2.
4. State what is meant by Group 7.
5. State what is meant by a transition metal.
[1 mark]
- forms at least one ion with an incomplete d-subshell
6. State what is meant by a complex ion.
[1 mark]
- central metal ion with ligands
7. State what is meant by a ligand.
8. State what is meant by heterogeneous catalyst.
[1 mark]
- different phase from reactants
9. State what is meant by homogeneous catalyst.
10. State what is meant by amphoteric.
[1 mark]
- reacts with acids and bases
11. Jac is asked about periodicity in a Eduqas Chemistry paper.
(a) [2 marks]
- atomic radius, ionisation energy, melting point
(b) [3 marks]
- explained by structure and shielding
12. Jac is asked about first ionisation energy in a Eduqas Chemistry paper.
(a) [2 marks]
- generally increases across a period
13. Jac is asked about Group 2 in a Eduqas Chemistry paper.
(a) [2 marks]
- reactivity increases down the group
(b) [3 marks]
- hydroxides more soluble, sulfates less soluble down the group
14. Jac is asked about Group 7 in a Eduqas Chemistry paper.
(a) [2 marks]
- oxidising power decreases down the group
15. Jac is asked about a transition metal in a Eduqas Chemistry paper.
(a) [2 marks]
- variable oxidation states, coloured ions, catalysts, complexes
16. Jac is asked about a complex ion in a Eduqas Chemistry paper.
17. Electron configuration of Fe (Z=26)
[3 marks]
- Final answer: [Ar] 4s² 3d⁶
18. Oxidation state of Fe in Fe₂O₃
20. Moles of Ca(OH)₂ from 0.10 mol Ca
21. A complex is octahedral. Bond angle
22. Percentage of Ca in CaCO₃
23. Jac carries out a Eduqas-style required practical linked to inorganic chemistry. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24. Jac carries out collecting valid data for inorganic chemistry. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25. Jac carries out drawing a graph for inorganic chemistry. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26. Jac carries out evaluating a method about inorganic chemistry. This is a typical Eduqas required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
27. Compare periodicity with first ionisation energy.
[4 marks]
- repeating trends across a period
- energy to remove 1 mol of electrons from 1 mol of gaseous atoms
- give one linked difference
28. Compare first ionisation energy with Group 2.
[4 marks]
- energy to remove 1 mol of electrons from 1 mol of gaseous atoms
- alkaline earth metals
- give one linked difference
29. Compare Group 2 with Group 7.
[4 marks]
- alkaline earth metals
- halogens
- give one linked difference
30. Compare Group 7 with a transition metal.
[4 marks]
- halogens
- forms at least one ion with an incomplete d-subshell
- give one linked difference
31. Apply your knowledge of a ligand to this situation: monodentate or bidentate
32. Apply your knowledge of heterogeneous catalyst to this situation: surface adsorption