Edexcel Jun 2012 Paper 1 Q22 (with explained solutions) |

Skip to content

Edexcel Jun 2012 Paper 1 Q22

Answers available below

22 (a) Define the term first ionization energy. (2)*(b) Explain why the first ionization energy of the elements down Group 1 decreases even though the atomic number increases. (2)(c) The eleven successive ionization energies for sodium are given below. Electron removed Ionization energy N-PRO1 10 11 4563 13352 16611 20115 141367 (i) Explain why the successive ionization energies increase. (1)10 *P39306A01024*<br />
*(ii) Explain how these ionization energies give evidence for the electronic structure of sodium. You may use a sketch graph if you wish. (2)(d) The first ionization energy of aluminium (element 13) is lower than that of magnesium (element 12). (i) Give the electronic structures of magnesium and of aluminium in s, p and d notation. (1) MagnesiumAluminium*(ii) Explain the difference in the first ionization energies of the two metals. (1)(Total for Question 22 = 9 marks) *P39306A01124* 11 Turn over<br />

Show answer

Question Number 22(a) Question Number *22(b) Mark Acceptable Answers Reject Energy given out for first mark Just gaseous element/ gaseous substance First mark:- Makes mention of energy/enthalpy/(heat) energy/heat (change) AND to remove an electron AND one mole/1 mol Second mark: Makes mention of gaseous atom(s) ALTERNATIVE ANSWER Energy change per mole for (1) X(g)X+(g) + e() (1) Mark the two points independently IGNORE any references to standard conditions Acceptable Answers Reject Any two from three:- (Atomic) radius increases/there are more shells/(outermost) electron further from the nucleus (1) Ionic radius increases Mark there is more shielding or more screening (down group) (1) the nuclear attraction decreases OR attraction between nucleus and (outermost) electron decreases OR the increased shielding/increased distance outweighs the increased nuclear charge (1) IGNORE any references to more protons and/just increasing nuclear charge IGNORE references to effective nuclear charge<br />
Question Number 22(c)(i) Any ONE from: Acceptable Answers Reject Mark (Electrons are being removed from an) increasingly positive ion/ charge on the ion (successively) increases/ increasing proton : electron ratio/ same number of protons (attracting) fewer electrons / ions get smaller/ the electron repulsion decreases/ the shielding decreases/ electrons (being removed are) closer to the nucleus/ effective nuclear charge increases<br />
Mark Reject 1st mark if the graph is sketched back to front Question Number *22(c)(ii) First mark: Two jumps Acceptable Answers Two (large) jumps (between 1st and 2nd and 9th and 10th IEs) (1) NOTE: A sketch graph with two (large) jumps can score this first mark Note if the jumps are specified, they must be between 1st and 2nd and 9th and 10th IEs Second mark: Electronic configuration of Na 2, 8, 1 mentioned in words, annotated on a sketch graph or drawn out in a diagram (e.g. electrons shown in orbits/shells around the centre of the atom) but NOT just inferred (1) ALLOW 1, 8, 2 OR 1s22s22p63s1 Mark the two points independently<br />
Question Number 22(d)(i) Credit any of the following Acceptable Answers Reject Mark representations (but need BOTH Mg AND Al to be correct) Mg 1s22s22p63s2 and Al 1s22s22p63s23p1 Mg 1s22s22p63s2 and Al 1s22s22p63s23p1 Mg 1S22S22P63S2 and Al 1S22S22P63S23P1 Mg 1S22S22P63S2 and Al 1S22S22P63S23P1 Question Number *22(d)(ii) NOTE: Acceptable Answers ALLOW an argument focusing on either the Al or the Mg atom EITHER In Al, (3p) electron (lost is) at higher energy/more shielded (by 3s electrons)/further from the nucleus IGNORE any reference to an unpaired electron in Al OR In Mg, (3s) electron (lost is) at lower energy/less shielded/ nearer to the nucleus/from a full subshell/from a full orbital/from (stable) (3)s2 Any reference to an Al atom being larger in size than an Mg atom scores zero overall. Mark Reject Al has one more shell than Mg Just (lost from) a new sub-shell Electron lost in Mg from a full shell<br />

Question 21 22 23 24 25 26

About us | Need Help? | Feedback

Proudly powered by WordPress | Theme: Sydney by aThemes.