1i. Silicon ( 1mark), many/ strong (1 mark) covalent bonds which required a large amount of energy to break so a high melting point ( 1mark)
ii) Argon ( 1mark), smaller atomic radius/more protons (1 mark) and similar shielding (1 mark)
iii) Chlorine (1 mark)
iv) ClF3 had a t-shape (3 bond pairs and 2 lone pairs). Trigonal planar should also be accepted. CCl2 had a bent shape (2 bond pairs and 1 lone pairs). (2 marks)
v) CCl2 had a bent shape. (1 mark)
vi) 0.5 Cl2 + 1.5 F2 goes to ClF3 (1 mark)
2i) 5s2 4d10 5p4 (Any order) (1 mark)
ii) Calculation and you should get 127.8 (1d.p.) (3 marks)
iii) Presence of other isotopes ( 1 mark)
iv) Te+ (g) + e- goes to Te (g) (1 mark)
v) The 128 Te + had the largest relative abundance ( 1mark) and current is proportional to abundance as more of the isotope = more electrons transferred from the detector to the ion = greater current produced ( 1mark)
vi) The 128 Te isotope ( 1mark) had two electrons knocked out (ionised twice) so it has a m/z ratio of 64. (1 mark) (Have to say 128 isotope)
vii) Same atomic radius ( 1mark) same number of protons and electrons so same attraction between the protons and the electrons so same atomic radius ( 1mark)
3i) Macromolecular ( 1mark)
ii) No delocalised electrons to flow through the macromolecular crystal and conduct electricity ( 1 mark)
iii) Hydrogen bonding ( 1mark)
iv) Bond angle in H2O2 is 104.5 ( 1mark)
v) Show hydrogen bonding between h2o2 and h2o. ALL partial charges ( 1mark). ALL lone pairs so 2 on each oxygen atom ( 1 mark) and attraction between delta + on hydrogen atom and lone pair on the Oxygen atom in the water molecule. H-O-H should be linear (1 mark).
vi) Oxygen is more electronegative than Sulfur (1 mark) due to less shielding etc. This means H2O2 has hydrogen bonding while H2S2 only has pd-pd interactions. This means that the melting point of H2O2 is greater than H2S2 ( 1 mark)
Now I have forgotten the order of the questions lol so sorry.
Saturated - Contains only C-C single bonds (No double C=C bonds) (1 mark)
Hydrocarbons - Contains carbon and hydrogen atoms only (1 mark)
The word ONLY must be used in both of these definitions to gain both marks (or words to that effect)
Fuels containing Sulfur are removed so that SO2 is not produced ( 1mark) from the combustion of these fuels. SO2 contributes to acid rain ( 1 mark).
Poly (propene) can be made from propene. ( 1mark)
Functional group isomer of propene was cyclopropane ( 1mark).
2,4-dichloro-2,4-dimethylhexane (1 mark)
The water of crystallization has 6 water molecules so x is 6 ( 3marks)
Evaporate the niso4.6h2o to constant mass ( 2marks)
SiO2 + 6HF -----> H2SiF6 + 2H2O ( 1mark)
C16H34 ----------> C8H18 + C2H4 + 2 C3 H6 ( 1mark)
C16H34 + 16.5O2-> 16CO + 17H2O ( 1 mark)
Draw 2,3,3-trimethylypentane (1mark)
3 HNO2----------> HNO3+ 2 NO + H20 (1mark) (Multiples accepted)
Ionic bonding ( 1 mark) with strong electrostatic forces of attraction ( 1mark) between the oppositely charged ions (Na+ and (N3)-)) ( 1mark)
Arrow from the N-N^- bond donated to the negative Nitrogen Ion ( 1mark)
N2O ( 1mark) (Other compounds will be accepted but this was the most obvious one)
MgN6 ( 1 mark)