aqa as chemistry unit 1 january 2013 unofficial mark scheme

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1)a mass number= the number or neutrons and protons
1c) ionisation
1d) the M/Z ratio
relative abundance

2a) cross higher then all of the others on the graph
2b) Al2+= 1s2 2s2 2p6 3s1
2c) Al+(g) +e---- Al2+ + 2e-
2d) because an electron on silicon is removed from the 3p orbital
2e)which in period 3 has the highest melting point
as no repelling pairs of electrons
meaning a lot of energy required to remove electron

3a) electronegativity is the ability of an atom to draw a pair of electrons towards itself in a covalent bond
b) electronegativity increase across period 3 as there are more protons meaning a higher nuclear charge. also there is a decrease in atomic radius

c) can't remember the compound but the answer was ionic bond
there is strong electrostatic forces of attraction between oppositely charged ions which require a lot of energy to overcome.

d) nitrogen and oxygen are both non metals
e) OF2 is simple molecular
f) you had to right some equation i can't remember

4a) 2,2 dimethyl propane
b) more surface area so increased rate of reaction (don't know what the second mark was)
c) there are 2 other position isomers
d) C9H20
e)CaO, as it is basic and SO2 is acidic (neutralises)
f) ethanol has a higher melting point as a result of hydrogen bonging. hydrogen bonds are the strongest intermolecular force and require a lot of energy to overcome.

can't remember much else on this question

5a) pV=nRT
the answer then had to be divided by 10 and * by 4 to get moles of NO
d) mole to mole ration then divide the number of moles by 0.25
f)so that there was complete combustion

6a) AsCl3 formed a triganol pyramidal with one lone pair
cl3+ formed v shaped with 2 lone pairs

b) the was equal repulsion between 4 bonding pairs of electrons

Modified once, last modified by vignesh on Thu 10th January, 2013 @ 19:14

Posted: 10-01-13 19:14 by vignesh

I thought this exam was so hard :((( 

Posted: 21-01-13 11:15 by Emily