DP Chemistry (last assessment 2024)

Test builder »

Question 18N.2.hl.TZ0.4

Select a Test
Date November 2018 Marks available [Maximum mark: 8] Reference code 18N.2.hl.TZ0.4
Level hl Paper 2 Time zone TZ0
Command term Explain, Predict, Sketch Question number 4 Adapted from N/A
4.
[Maximum mark: 8]
18N.2.hl.TZ0.4

Properties of elements and their compounds can be related to the position of the elements in the periodic table.

(a)

Explain the decrease in atomic radius from Na to Cl.

[2]

Markscheme

nuclear charge/number of protons/Zeff increases «causing a stronger pull on the outer electrons» ✔

same number of shells/«outer» energy level/shielding ✔

 

Accept “atomic number” for “number of protons”.

(b)

Explain why the radius of the sodium ion, Na+, is smaller than the radius of the oxide ion, O2−.

[2]

Markscheme

isoelectronic/same electronic configuration/«both» have 2.8 ✔

more protons in Na+ ✔

(c)

Sketch a graph to show the relative values of the successive ionization energies of boron.

[2]

Markscheme

Sketch showing:

largest increase between third and fourth ionization energies ✔

IE1 < IE2 < IE3 < IE4 < IE5 ✔

(d)

Predict, giving your reasons, whether Mn2+ or Fe2+ is likely to have a more exothermic enthalpy of hydration.

[2]

Markscheme

Fe2+ AND smaller size/radius

OR

Fe2+ AND higher charge density ✔

 

stronger interaction with «polar» water molecules ✔

 

M1 not needed for M2.

Syllabus sections