AQA GCSE Chemistry Unit 1 - June 10th 2014 OFFICIAL THREAD

Scroll to see replies

Reply 380

Sumaya_27

Original post by Blueyy__

when you do, can you quote me in it so i get a notification plz? :biggrin:

-BTW, that would be awesome :smile:

AND ME @sumaya_27

Reply 381

TheGreatImposter

Original post by blue.panda

Oh no did we need a conclusion?

It only asked for advantages and disadvantages of biodiesel not petroleum, I made a few points but my answer was mainly on biodiesel, did I do that wrong?

Posted from TSR Mobile

Reply 382

waterboo

For the question about testing for saturated and unsaturated using Bromine
water. If i had the inverse answer:

"The more drops of bromine water, the more saturated it is..." How many marks would i get if i put C and D were more satuated, and A and B were less saturated than vergo?

I know this was a daft mistake

Reply 383

xnads

Guys for the 6 mark question I gave advantages on Biodiesel and then compared it to for exapmple I said, biodiesel Is a renewable energy source whereas petroleum isn't and will likely run to out. I wrote 4 advantages comparing it to petroleum but for the disadvantages I didn't compare anything..just wrote one disadvantage for petroleum and no conclusion. Will I still get the 6 marks?! :frown:

Reply 384

091098

Original post by xnads

Wasn't C the one with the more saturated fats? I can't really remember what company had the less drops of bromine water but the less drops the more satured. And for the conclusion I just compared the named company with A, B, C, D. I talked about how some companies had more saturated fats and some other companies had less. I also included numerical data. Did I get the marks guys?

The question was showing how many drops it needed to cause a reaction (I think) therefore the ones with the least drops would be unsaturated as they needed the least amount to react with bromine (and unsaturated reacts with bromine so the ones that reacted best with bromine are unsaturated) and the ones that reacted best are the ones that needed less to react.

Reply 385

Blueyy__

Original post by GoldGhost

UNOFFICIAL MARK SCHEME FOR C1 BY ARITHMATICAE

The Answers

according to this, i have got around 47-51 marks lol :P

Reply 386

Sumaya_27

Original post by azrafc

The question didnt ask for one, so no.

1 mark

1aii) Hydrogen + Oxygen ==> Water

do we still get mark for hydrogen oxide

Reply 387

GoldGhost

Original post by Blueyy__

according to this, i have got around 47-51 marks lol :P

I wish I could say that same, do you mind filling in the marks for the questions that I've left blank please? I think it's really helpful to have the marks that the exam board allocated for each question underneath the answer.

Reply 388

GoldGhost

Original post by Sumaya_27

1 mark

1aii) Hydrogen + Oxygen ==> Water

do we still get mark for hydrogen oxide

I believe so :-)

Reply 389

Blueyy__

Original post by Sumaya_27

1 mark

1aii) Hydrogen + Oxygen ==> Water

do we still get mark for hydrogen oxide

no..

Hydrogen Oxide = HO
water = H2O

maybe.. idk, most probably not though as it was on the first page of the exam

Reply 390

091098

Original post by xnads

Isn't the more drops the more unsaturated? That's what my science teacher told me.

wasn't the table showing how many drops were needed for a reaction to occur? if it was then it would be the less drops the more unsaturated (as they didn't need as much to react which shows it is unsaturated as unsaturated reacts with bromine)

Reply 391

suprajasivaramak

Original post by PRITHVINAGRAJ

i put control variable was volume of beaker, would that be correct?

I think so :smile:

Reply 392

Blueyy__

Original post by 091098

well, i read that too :P
'table showing how many drops were needed for a reaction to occur'

Reply 393

suprajasivaramak

Was oil from company C the healthiest as its was more unsaturated (due to fewer drops of bromine water?)

Reply 394

f.loco

Combustion of limestone produce calcium oxide which is a solid and has the mass always so it can never be zero grams. Thr other product is co2 which is a gas and has virtually no mass hence the mass of products are reduced. If theres more co2 produced, therell be less calcium oxide produced and there fore a lower mass(below 2.2g)

Is this right? If not. Would i get any marks?? Also was this a 4marker?? Guys dont be nice. Just be straight up
Posted from TSR Mobile

Reply 395

muntilol

Original post by suprajasivaramak

Was oil from company C the healthiest as its was more unsaturated (due to fewer drops of bromine water?)

I don't remember if it was company C, but yh the fewer the drops the more unsaturated the oil.

Reply 396

MeganC1384

Original post by Blueyy__

well, i read that too :P
'table showing how many drops were needed for a reaction to occur'

I think it said something like 'number of drops of bromine water that reacted' meaning each drop added turned colourless and therefore, if there were more drops that reacted (ie turned colourless) there were more alkenes so more unsaturated fats

Reply 397

chemistrypower

Question 1)

A)Electronic structure of carbon atom. 6 altogether, 2 on the inside, 4 on the outer shell.
(1 mark )

B) hydrogen + oxygen --------> water
(1 mark)

C) coal contains sulfur, oxygen, carbon....... Name products formed and effect on environment: (4marks)
Sulfur dioxide = acid rain = kills fish and plants
Carbon dioxide= global warming
Nitrogen oxides=acid rain
Carbon monoxide= soot and global dimming

2)a
ethene is formed by hydration. What is hydration (1mark)
reacting (ethanol) with steam (h2O)

2b) suggest how
Yeast is removed from ethanol and water and how ethanol is removed from water:
Filter yeast
Distil solution
(2marks)

3) (6 marks) advantages and disadvantages of biodiesel over petroleum diesel from crude oil
(Marks scheme and question in the images....)

4)add one drop of bromine at a time and record how many drops needed to react then repeat twice (3marks)

4b) which one is the anomomly? Test A result 2 as 17 does not fit in with 25 and 27 (2 marks)

4b) control concentration of bromine/amount of each drop
(1mark)

4c) conclusions
I said A was the most unsaturated and Viego was 3rd saturated and I think C was least saturated.
(3marks)

Name the the process of extracting copper from plants (1mark) :
Phytomining

4B) 2 reasons why is copper extracted from the land by this process instead of smelting? (2 marks)
1) Because it is a low grade ore and smelting uses lots is of energy so it would be more profitable phytomining
2) not too sure on the second reason

4C) 2 reasons why is copper extracted using scrap iron to displace copper? (2marks)
1) it is more reactive than copper
2) it is cheap

D) image of electrolysis explain how copper forms (2 marks)
Copper 2+ attracted to negative. 2 electrons at gained to form copper atoms

5) thermal decomposition .... Calcium oxide and carbon dioxide (3marks)

b) average 1.8 (1mark)

c)
the maximum wasn't 2.2 because it didn't fully decompose so co2 wasn't all produced and released/escaped

impurities
(4marks)

6)why did scientist not believe Wegener theory of continent moving ?
He was an astronomer (might not qualify for the mark)
(1mark)

b) how are continents moving (mention X and Y)
Radioactive processes
Heat created
Convection currents in Y( Mantle)
Rise and push X(crust)
(5marks)

Why is carbon dioxide removed?
Because it freezes... This could block pipes. (2mark)

Circle one gas that doesn't condense when cooled to -200 degrees :
Argon OR neon OR nitrogen Or oxygen
I think it is NEON
(1mark)

Which gas is separated with oxygen and why?
Argon because it has similar boiling point to oxygen (3degrees different.)
(2 marks)

7)

What are the conditions of cracking:
Vapour over:
Catalyst (aluminium oxide)
400-700 degrees
(2marks)

Name a method of separation these crude oils
Fractional distillation (1mark)

Draw butene
(1mark)

How is poly(something) formed?
Monomers join together, open bonds to form large molecules (polymers)
(2marks)

Sorry this is not very good as I did it on my phone. I'm missing 3 marks and they might be in random orders. Tell me what I'm missing please, I can't remember.