[Welbeck]

The thing is some people predict high grade boundaries because people on this forum found it easy, however, most people that come on here are the "clever" people but there are millions more children in the UK who may have found it hard

[TW2112]

(Original post by Aarongreatbanks)
Here's my full answers, let me know what you think

1a) The water is hard because it contains magnesium ions. When sodium carbonate is added it reacts with the magnesium sulphate to form a precipiate of magnesium carbonate. Because the magnesium is removed from the water it's soft and the and the sdoium ions displace the magensium ions (3)
b) Result is anomalous(1)
ii) 68 degrees C (1)
iii) because the water would evaporate at 100c (1)
c) Because it isn't a curve and as the temperature increases the solubility doesn't always increase. Also, the solbuility increases to 68 C and then falls when it should continue going up (2)
2 a) They are metals and they all have one electron in their outer shell (2)
b) He put two elements in same box more than one for example he put Di and Mo in the same box. Also, it wasn't accepted as he put metals and non metals in the same group, for example he put gold and oxygen in the same group and also he put elements in groups with elements that they don't react similarly to for example he put copper and lithium in the same groups(3)
c) He considered undiscovered elements and left gaps for them so that they could easilly fit into his period table (2)
3 a) Transition metals are strong,malleable and don't corrode easily (2)
b) The electrons of transition metals fill up the 3rd enegry level after there are two in the 4th shell, meaning that they usually have the same number of electrons in their outer energy level, making them have similar properties (2)
4 a) H+(1)
b) pH of weak acid higher and the pH of a strong acid is lower as it's fully ionised in water so there is more hydrogen ions in solution so they have lower pH (2)
c) 0.61 mol/dm3 (3)
ii) 12g (2)
5 a) i) Bubble gas through limewater and limewater should go cloudy (2)
ii) Wrong, as ammonia gas did not form when sodium hydroxide was added (2)
iii) Right , as white precipitate formed after silver nitrate added (2)
b) i) Atom Absorption Spectroscopy (1)
ii) Measure smaller amounts (1)
6. Chlorine atoms are smaller so the electrons in the outer energy level are closer to the postive nucleus, so they are more strong sttracted to the positive nucleus. Also, in chlorine, the electrons are less sheilded from the positive charge on the nucleus so they are ore strongly attracted to the positive nucleus. Because of this there are more strongly attractied to the nucleus so any electron that would be added to the outer energy less is gained more easily (3)
7 a) -810 kJ/mol (3)
b) Because the energy released from new bonds forming is more than the enrgy required to break the existing bonds(1)
c) Because it provides the activation energy (1)

I think i got 36/45 :/

I think i dropped marks here

iii) because the water would evaporate at 100c (1)-Lose 1
c)Because it isn't a curve and as the temperature increases the solubility doesn't always increase. Also, the solbuility increases to 68 C and then falls when it should continue going up (2)-Lose 1
3 a) Transition metals are strong,malleable and don't corrode easily (2)-Lose 1
ii) Wrong, as ammonia gas did not form when sodium hydroxide was added (2)-Lose 2
iii) Right , as white precipitate formed after silver nitrate added (2)-Lose 2
b) i) Atom Absorption Spectroscopy (1)-Lose 1 as i mispelt it
ii) Measure smaller amounts (1)-Lose 1

Can you see where i've dropped or gained marks compared to what i've put please?

For 1c you'll get the 2/2 marks mate. If you mention that it's not a curve and the solubility doesn't always increase as temperature does you would have not lost any marks

[Fordey]

For 5bi I put spectroscopy tht was it wud I get a mark

[Student95]

(Original post by Fordey)
For 5bi I put spectroscopy tht was it wud I get a mark

Yes almost definitely, you don't need to be specific

[Student95]

Do you think I would get the mark for the solubility question by saying:

100 C is the boiling point of water so it would be difficult to tell the solubility.

Bit worried because I didn't actually say that it boils, I just referred to the boiling point.. :/

[SampritB]

For 5bi I put Atomic Absorption, do you reckon I would get that?

[James_01]

probably not you need to mention spectroscopy

[bobe25]

For 1 b)iii)Will i get a mark for saying they were able to obtain a pattern?

[TheSilentFez]

I think I got 40/45.
For the question regarding Newlands's Periodic Table and why it wasn't accepted, I said:
-He put two elements in the same box in the same group in some cases
Which is a correct answer, but I also said:
-He could not explain the patterns he found
-The patterns he noticed only worked for the first 15 elements (this wasn't mentioned, but I learnt it as a fact)

Do you think I will get those last two answers? They are technically correct, but whether AQA accept them or not is another matter entirely.
If I do get the marks, then my score is probably 42/45

I wrote the answer you give for 3 b), but I was told elsewhere that it was wrong and has something to do with the 3rd shell being filled rather than the outer shell having the same amount of electrons.
If I do get both marks for that then my score goes up by one.
My maximum mark is therefore 43/45

I lost the marks on question 1 c) because I was running out of time and wrote some rubbish down. ("The solubility only increases until 68 degrees, then it increases"- basically pointing out the obvious)

[Fas]

Looking like 41/45 for me :P

[James_01]

(Original post by bobe25)
For 1 b)iii)Will i get a mark for saying they were able to obtain a pattern?

Possibly. Most likely the guy marking would use discrepancy. If you have lots of answers like this then no. If this is the only dodgy answer then yes.

[tinkerbell1109]

(Original post by Aarongreatbanks)
will i get the mark for atom absortion spectroscopy not ATOMIC absorbtion spectroscopy

Probably

[tinkerbell1109]

(Original post by TheSilentFez)
I think I got 40/45.
For the question regarding Newlands's Periodic Table and why it wasn't accepted, I said:
-He put two elements in the same box in the same group in some cases
Which is a correct answer, but I also said:
-He could not explain the patterns he found
-The patterns he noticed only worked for the first 15 elements (this wasn't mentioned, but I learnt it as a fact)

Do you think I will get those last two answers? They are technically correct, but whether AQA accept them or not is another matter entirely.
If I do get the marks, then my score is probably 42/45

I wrote the answer you give for 3 b), but I was told elsewhere that it was wrong and has something to do with the 3rd shell being filled rather than the outer shell having the same amount of electrons.
If I do get both marks for that then my score goes up by one.
My maximum mark is therefore 43/45

I lost the marks on question 1 c) because I was running out of time and wrote some rubbish down. ("The solubility only increases until 68 degrees, then it increases"- basically pointing out the obvious)

I think you'lll probs get 2 marks for the Newlands. Well done

[ChemicalFreak]

(Original post by michelfish)
Here you go!

4c) ii)

Volume of NaOH x Concentration of NaOH / Volume of Vinegar

(30.5 x 0.5 / 25)

= 0.61 mol/dm^3


4c) iii)

Concentration of vinegar x Relative formula mass of ethanoic acid

(0.8 x 60)

= 48 g/dm^3

a dm^3 is equal to 1000cm^3

the question asks for the answer in g/250cm^3

1000 / 4 = 250

so

divide 48 by 4

(48 / 4)

= 12g (per 250cm^3)

Thankyou Very Much!! i got 4cii right but i forgot to divide 48 by 4 in 4ciii!

[BossUK]

For chloride ions i said no because they added hcl but they didnt add nitric acid and the test for chlroide ions is adding nitric acid followed by silver nitrate which forms a white precipitate.

[James_01]

(Original post by BossUK)
For chloride ions i said no because they added hcl but they didnt add nitric acid and the test for chlroide ions is adding nitric acid followed by silver nitrate which forms a white precipitate.

yeah thats what i put as well

[wozzakeeps]

According to that mark scheme I think I only dropped 4 marks

[tinkerbell1109]

(Original post by BossUK)
For chloride ions i said no because they added hcl but they didnt add nitric acid and the test for chlroide ions is adding nitric acid followed by silver nitrate which forms a white precipitate.

I'm really confused cos I'm reading different things everywhere about this q. I put down yes for this one and yes for the one above which is ovb wrong and my reading error.

[James_01]

yeah i think the detection of chloride ions was badly worded as depending on how you interpreted the information HCL was either added or not added which would agree or not with agree with the students conclusion.

[skaran]

I need 82 ums for an A*. What score do you reckon I need?