The Student Room Group

AQA GCSE Chemistry - C2 & C3 (14th May 2015)

Scroll to see replies

Original post by t.thompson22
I got PB2O3

Do you remember what you put exactly? (:


I can except the masses it gave us for the lead and oxygen, does anyone know ?
But I did:

Pb O
207 divided by the mass given 16 divided by the mass given
(Thats where I mixed up, I usually do the other way round but my head jus blanked for some reason!)

Then I divided the two results which I got for oxygen because it was the smallest and got Pb3O2 which I know is wrong, I was so stupid, I knew it before!
Original post by G_Head
Think I put hydrogen gas , chlorine gas and then sodium hydroxide!:confused:


As fas as I can remember from this morning, the question asked you for the "products produced other than chlorine." Sodium Hydroxide and Hydrogen is correct!
Anyone doing wjec spanish tomorrow? Official threads links?
I found C2 much easier than B2, but I'm not sure if I understood the question where you had to fill in the blanks.

I thought you had to fill the blanks with element names so I put hydrogen in the first blank and guessed helium in the second blank.

Not sure why I guessed helium to be honest, just thought I remembered my teacher mentioning it.
i wrote that all metal oxides are alkali, is that wrong???
Original post by ambarellarose
I can except the masses it gave us for the lead and oxygen, does anyone know ?
But I did:

Pb O
207 divided by the mass given 16 divided by the mass given
(Thats where I mixed up, I usually do the other way round but my head jus blanked for some reason!)

Then I divided the two results which I got for oxygen because it was the smallest and got Pb3O2 which I know is wrong, I was so stupid, I knew it before!


I'd recommend looking at past mark schemes that give the information for answering empirical formulas. I reckon if the examiner is generous you could net at least one of two marks for showing the first stage of workings! You just got the mass given to you the wrong way round.
on the 5mark question in c3 where you had to evaluate the two methods what were points you could put? I had no understanding of method one and am so scared ive just lost all 5 marks:frown:
Original post by t.thompson22
As fas as I can remember from this morning, the question asked you for the "products produced other than chlorine." Sodium Hydroxide and Hydrogen is correct!


I got that aswell :biggrin:
Reply 888
Avatar for Hxzel
Hxzel
6
For the ions question I wrote the ions so like I wrote Fe+2 instead of Iron (II) will that matter?


And are metal oxides bases or alkalis? I
Put base?

Posted from TSR Mobile
Original post by Palette


We are indeed!
Reply 890
Avatar for neil20143
neil20143
OP
4
I'd say Grade Boundaries would be slightly lower than last year for both:
Unit 2 : 46/60 A*
Unit 3: 44/60 A*

The problem with Unit 3 was that some of the questions were either know it or not.

Did anyone else get Sulfuric Acid as the catalyst to make Ethyl Ethanoate?
Original post by lewiswallis
i wrote that all metal oxides are alkali, is that wrong???


Technically your answer is correct, metal oxides and metal hydroxides dissolve in water. Therefore they are soluble compounds which are alkalis!
They neutralise with acids.

Acid + Metal Oxide ->> Salt + Water
(edited 8 years ago)
No I got that answer too!!!
Original post by Palette
yo im tellin u postin graid bawnderees dont maik mee clvr u havnt seeen hao meni sili mistaiks i maid.

For example, I had no clue when I came to the question which asked how the scientist could find the concentration of barium sulfate (or was it barium hydroxide?). I don't like questions which give you loads of information about the method of the experiment, so I answered this last. All I could think of was that the yield of the reaction is never 100% so this affects the calculation of the concentration. I also put 'carbon dioxide' instead of hydrogen as the gas released in the reaction between sodium and ethanol, because I was most likely thinking of the reaction of ethanol and oxygen instead. There are also many two mark questions on ammonia, and I don't know whether what I've written qualifies for two marks or one mark.

I'm still remaining hopeful that the grade boundaries will be low.



Hahaha honestly I don't think anyone had a clue on that 5 marker. I said stuff like more accurate and sensitive for titration, however more expensive, require indicator, subjective as to when reaction finished, burette for example could be dangerous (sharp). Then method 1 I said less sensitive, easier, however more steps where human error could go wrong e.g. filtration, subjective as to when all solid has formed, stuff like that can't remember really!

One marker questions not a big deal, I did that I said boiling point decreases in halogens because iodine is a liquid for example.... how bloody stupid! I really should have re read my answer as I would've probably picked up on that XD I loved the ammonia questions, hopefully it will be two marks for both of us :smile:
(edited 8 years ago)
Original post by Positivedani
Urgh I totally messed up the last page! It all started with the amount where I put 30cm, then I didn't read the graph properly so put 38degrees as the overall change! That means I got the Q=mcdeltaT question wrong, and then for the last question I had no clue so wrote the neutralisation reaction will releade the same amount of energy -.- that page will bring my grade right down ergh!

i think it will be an error carried forward :smile:
Omg I put Pb3O2 by accident I am such an idiot
Original post by PawanAviator
We are indeed!


That's good, considering that it seems like at least half the people got the other answer.

But then I made a few unforced errors myself as well.
Original post by lewiswallis
i wrote that all metal oxides are alkali, is that wrong???


nope...right if anything..I put that and my teach verified it sooo ..all gud!:smile:
Original post by Hxzel
For the ions question I wrote the ions so like I wrote Fe+2 instead of Iron (II) will that matter?


And are metal oxides bases or alkalis? I
Put base?

Posted from TSR Mobile


i put alkali damn but it was base:angry:
Reply 899
Avatar for neil20143
neil20143
OP
4
For Metal Oxide I wrote base?

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you