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AQA Chemistry Unit 3 GCSE 24.05.12

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For the 12g question I did this:

(0.8 / 1000) * 250 * 60 = 12

Because the concentration is 0.8 you put it over 1000 to get what it would be in 1000. Then times this by volume and then by the RFM and you get 12. Just scribbled this down in the exam did'nt really know what I was doing but apparently its right. So s'all good!
Reply 81
Original post by own
I was iffy on the newlands one as well, just put down literally everything I could think of.


Thing is i knew that in newlands' day they didn't have any idea about protons, neutrons, and electrons, which left me stumped. I was worried that anything which came after newlands time would be ignored, or worse, would negate any mark attained. So i scribbled some bull**** down and moved on haah
Reply 82
On the Newlands one I put:
-Metals and non-metals were mixed.
-New elements could not fit into the table.
-In each group there were more than eight elements.

How many marks? :smile:
Reply 83
for newlands i put:

it was late 1800s and people didn't know much about atom structure and so were skeptical about his table
he wasn't a famous/established scientist with previous discoveries
he didn't leave gaps for undiscovered elements
For the alkali metal one I said that they are very reactive water and are less dense an water, would I get those two marks?


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Original post by kashagupta
For the alkali metal one I said that they are very reactive water and are less dense an water, would I get those two marks?


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i put exactly that!
Original post by pointfortytwo
i put exactly that!


Hahaha good! Wow my spelling was atrocious in that :') the iPad doesn't like me :P


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what do you guys think that the grade boundaries will be for A* A and B
Reply 88
Original post by SaraBB
for newlands i put:

it was late 1800s and people didn't know much about atom structure and so were skeptical about his table
he wasn't a famous/established scientist with previous discoveries
he didn't leave gaps for undiscovered elements


i said he didnt leave gaps,
he mixed metals and non metals
there was no evidence to support his theory
Reply 89
Original post by ismailmahmood123
what do you guys think that the grade boundaries will be for A* A and B


Personally quite low, but that's always the case with these modular exams, because so many people take it over the country, and many find it difficult.


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Reply 90
Original post by iBillyB
Pardon me if I'm wrong :tongue: but 0.5/1000 x 31.5 = 0.01575, 0.01575/25 x 1000 = 0.63?

I think anyway :tongue:


The working out was 0.01525/25/1000=0.61
Reply 91
Relatively easy a paper but a few tough Qs.

Predicted grade boundaries:
A* = 34/35 (100 UMS = 37+)
A = 30/31
B = 26/27
Original post by TW2112
Relatively easy a paper but a few tough Qs.

Predicted grade boundaries:
A* = 34/35 (100 UMS = 37+)
A = 30/31
B = 26/27


Ahhhh I reeeeeealllly hope you're right :tongue:
Original post by Maisie10
i said he didnt leave gaps,
he mixed metals and non metals
there was no evidence to support his theory


I wrote that he put 2 elements in one box,
he put metals and non-metals together
and he didn't leave any gaps :wink:
Reply 94
Original post by TurboAnouny123
I wrote that he put 2 elements in one box,
he put metals and non-metals together
and he didn't leave any gaps :wink:


I put:
He didn't leave gaps
He had 2 elements in some boxes
He worked in a sugar factory therefore other scientists mocked his work :biggrin:

LOL =P
Reply 95
Original post by emily_p3
Any Thoughts on the Chemistry paper?

My Calculation Answers
Concentration: 0.61
Mass: 12g
Energy Change: -810KJ

Anyone have any other answers? :biggrin:


Didnt it ask for the amount of Centimetres squared of ethanoic acid, but beforehand it had given us the amount in decimetres squared…

I therefore wrote the answer as 1.2g because it should be ten times smaller.. surely?
yeah i got
0.61
12g
-810J
however i spoke with a bunch of guys after the exam who all put +810, they said because it was burning it was an exothermic reaction so the answer must be positive

but then i spoke with some other guys who said they did a past paper with a similar question and they gave the mark irrespective off the sign.....
Reply 97
Original post by Rizzlemysterdon
yeah i got
0.61
12g
-810J
however i spoke with a bunch of guys after the exam who all put +810, they said because it was burning it was an exothermic reaction so the answer must be positive

but then i spoke with some other guys who said they did a past paper with a similar question and they gave the mark irrespective off the sign.....


You are right, they are wrong. Exothermic is always a negative sign because it releases energy. Endothermic is positive...


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Reply 98
for the energy change reaction question if you get the answer wrong, but still have the negative sign (-) and all of your working out is written clearly are you likely to gain some marks like 1 or 2 out of 3?
Reply 99
Original post by pawandeep
for the energy change reaction question if you get the answer wrong, but still have the negative sign (-) and all of your working out is written clearly are you likely to gain some marks like 1 or 2 out of 3?


I think you can get 1 or 2 marks for the working out, but you won't for the negative sign because in previous mark schemes it has said 'ignore signs', but if your working is correct and leads to the answer you put, even if it's wrong, I think you should still get 2/3 :smile:

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