** A few things left out cant remember question, also if your a person who worries about answers DO NOT read the unofficial mark scheme as it is really UNRELIABLE, and real mark scheme may have all the points YOU wrote and nothing written below. And ofcourse the questions below are not in order**
1 a) table [2 marks]
151Ce2+ :
Protons: +1, 58
Neutrons: 0, 93
Electrons: -1, 56
1 b) name the other product [1 mark]
Hydrogen gas
1 c) write the formula of the main product [1 mark]
- Cant remember the answer lol.
cii) What happens in terms of electron transfer (1)
Ce - gets oxidised from 0 to +3 (loses 3 electrons)
ciii) Why is it a salt? (1)
H+ replaced my metal ion.
1 d) define 'emperical formula' [1 mark]
Simple whole number ratio (of atoms of elements in a compound.)
1 e) calculate the emperical formula [2 marks]
Tm2S3O12
1 f) How many electrons in the fourth shell? [1 mark]
32
1 g) How many orbitals in the third shell? [1 mark]
9
2. a) successive ionisation energies of aluminium [2 marks]
Jump between 3rd and 4th ionization and jump between 11th and 12th.
2. b) define 'ionic lattice' [2 marks]
The attraction between oppositely charged ions held together by ionic bonds to form a giant ionic lattice.
2c) Define base and alkali using species. (2)
Base is H+ (proton acceptor)
Alkali soluble base that produces OH- ions in solution
2d) What reagent can be used to make calcium nitrate.
HNO3 reagent (1)
2e) Write the equation for this reaction.
2HNO3 + CaCO3 -> Ca(NO3)2 + H2CO3 (2)
2d) Chlorine gas is pumped into a solution of potassium iodide what will the student see?
Colour change to brown
2f) Write an ionic equation for this reaction. Ignore state symbols.
Cl2(g) + 2I-(aq) ---> 2CL-(aq) + I2(g)
3 a) draw the dot and cross diagram for BF3 [2 marks]
3 b) TITRATION CALCULATION [3 marks]
Need more info for this.. what was the question based on? cant remember.
3 c) explain the electrical conductivity of the following in solid and molten states [5 marks]
Metallic bonding = delocalised electrons therefore can conduct in both states
Covalent bonding = No delocalised electrons or mobile ions in both states. Therefore cannot conduct in both states.
Ionic bonding= Can conduct in molten due to mobile ions but not in solid due to absence of mobile ions.
3 d) define covalent bonding [1 mark]
Shared pair of electrons between two atoms.
3 e) Draw the 3D diagram of H2CCl2 and include the polarities [2 marks]
Both Cl slightly negative and Carbon slightly positive. Hydrogen no charge.
3 f) explain why this molecule is polar [1 mark]
No symmetry in molecule therefore dipoles do not cancel out.
4. THERE WERE 5 CALCULATIONS [5 MARKS IN TOTAL]
a) 0.144
b) cant remember
c) 0.0184mol
d) 1.55g
5. FLOWCHART GIVEN:
5 a) Thermal decomposition [1 mark]
5 b) Ca + 1/2 02 ---> CaO
5 c) CaCO3 --> CaO + CO2
5 d) percentage calculation [1 mark]
55%
6.a)explain why the attraction between the nucleus and outermost electrons increases across a period? [3 marks]
- Shielding remains the same
- Nuclear charge increases as proton number increases.
- Atomic radius decreases
- Ionization energy increase.
6.b)explain in terms of the intermolecular forces present, the difference in melting points shown in the table [6 marks]
NH3 = Hydrogen bonding between molecules.
B2 AND F2 = Van der waal forces between molecules.
B2 has strong van der waal forces, stronger than F2. Van dar waals in bromine are stronger than the hydrogen bonds in ammonia therefore bromine has a higher boiling point as more energy required to overcome these forces.
B2 has stronger van der waals the F2 as it has more electrons (so more instantaneous dipoles are likely to occur).
If anyone remembers any other questions or answers please feel free to post below. This is just a rough mark scheme, real mark scheme will prob have loads of other points to get marks from.