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AQA C1 Chemistry exam 18th May 2017

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Phytomining: plant crops in soil with copper ore. The crops absorb it through their roots. Burn the crops. React the ash with sulfuric acid to get a copper ion solution. Add scrap iron because it is cheap to displace the copper ions and make copper metal. So electrolysis to purify the copp

Original post by Yorrick

Bioleaching involves adding bacteria to copper ore.
The bacteria feeds on the ore and makes a copper ion solution.
Add scrap iron to the solution (because it's cheap and more reactive than copper) to displace the copper and get copper metal.
Do electrolysis on the copper to purify it. Otherwise it would not be useful as copper wires.

Thank you soo much!

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Reply 41

Yorrick

Original post by Lemur14

Hello,
Thank you very much for giving up your time to do this! I'm basically going through the entire spec now so I'll add questions as I get to them.

First one:
Explain the two methods for extracting oils in clear terms

Thanks once again!

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Sorry, plant oils.

Cold pressing: The olives are pressed and oil comes out. This works if the oil is not soluble in the other liquids in the olives.

Steam distillation: This works in the same way as fractional distillation, except you don't heat the mixtures direcly as this will break down some of the molecules in the oil and ruin the flavour. Instead, you boil water over the oil mixture so that the temperature does not go much above 100oC. The oil evaporates and is then condensed and extracted. You may have seen it happening with orange peel.

Reply 42

rebeccahurstt

can someone pls write out a solid 6 mark answer on fractional distillation

Reply 43

Yorrick

Original post by holly 1234456

hi can you tell me briefly what Urey and millers experiment was about. plz

Yes - Miller and Urey took some chemicals that they thought might have been in the Earth's early atmosphere and tried to create the chemicals that are in living things. Tey selected chemicals and that have the same elements as amino acids (the molecules that make up protein) - these molecules were ammonia (NH3), methane (CH4), water (H2O) and hydrogen (H2).

They then passed an electric current through it to simulate the passing of billions of years in a hot atmosphere and they got 11 amino acids.

They were trying to see if life could arise from basic chemicals and they didn't get that. Their experiment had some flaws - they picked their gases based on the idea that they thought they could make amino acids from them. They were not sure what gases were actually in the early atmosphere and in what proportions and their electricity may not be a proper simulation of time passing.

Other theories of how life began are: The Murchison meteorite - a meteorite that crashed to earth and may have had chemicals that living things have and that bacteria may have formed in undersea volcaninc vents.

Reply 44

Yorrick

Original post by ppggjj

separating gases in air has never come up, might be the 6 marker
7.5

Question 6b on the June 2014 paper was about separating gases in the air. Still might come up, though.

It's fractional distillation, just like with crude oil except first you cool all the gases down to liquids, then warm them up again.

CO2 is removed because it is solid and would block up the pipes

Helium does not condense because its boiling point is so low.

Oxygen and argon's boiling points are so similar, they condense together.

Reply 45

Boy2001

Hi what do you mean by 'metals as structural materials'? Alloys or the properties of different metals (copper, aluminium etc) or something else? Thanks, your help is much appreciated

Reply 46

Hello50

Do you think the Miller-Urey Experiment will come up tomorrow?

Cramming tips please

Didn't we just have this exam why you studying now?

Reply 49

Yorrick

Original post by rebeccahurstt

What period table knowledge do we need to specifically know?

Each element has 2 numbers - the top number is the mass number, which is the number of protons and neutrons added together.

The bottom number is the atomic number (aka proton number) which is the number of protons.

The mass number is higher than the atomic number for all elements apart from hydrogen. Hydrogen has no neutrons so its mass number and atomic number is both 1.

In an atom of an element, the number of electrons is equal to the number of protons.

The main thing is that the group number is the same as the number of electrons in the outer shell.

Elements in group 1 lose 1 electron to form 1+ ions.
Elements in group 2 lose 2 electrons to form 2+ ions.
Elements in group 3 lose 3 electrons to form 3+ ions.
Elements in group 5 gain 3 electrons to form 3- ions.
Elements in group 6 gain 2 electrons to form 2- ions.
Elements in group 7 gain 1 electron1 to form 1- ions.

Elements in group 0 and group 4 don't form ionic bonds.

Group 0 elements have full outer shells so they do not react.

Reply 50

Hans_Weimar

Original post by Lara121

Cramming tips please

You have the exam at 3am?

Reply 51

Lemur14

Volunteer Section Leader

Original post by Luke7456

Didn't we just have this exam why you studying now?

C1 chemistry core GCSE is tomorrow

Original post by Hans_Weimar

You have the exam at 3am?

Presumably the op wants 3 hours sleep

Op I would suggest something like a C1 summary video on YouTube. I watched a 48 minute one this evening, which really refreshed my mind as to what is in C1 seeing as I literally hadn't looked at it since we finished it in very early year 10
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(edited 6 years ago)

Reply 52

abc_123_

Original post by Lara121

Cramming tips please

Don't cram ... pack your pencil case and have a good night sleep so you're not tired for tomorrow xx
Whatever you do won't change anything so don't bother

Good luck for tomorrow xx :smile:

Reply 53

Hans_Weimar

Original post by Lemur14

C1 chemistry core GCSE is tomorrow

Presumably the op wants 3 hours sleep

Op I would suggest something like a C1 summary video on YouTube. I watched a 48 minute one this evening, which really refreshed my mind as to what is in C1 seeing as I literally hadn't looked at it since we finished it in very early year 10
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I think I did worse than I could have in edexcel c1 because I didn't sleep enough last night

smh regrets

Reply 54

Luke7456

Original post by Lemur14

C1 chemistry core GCSE is tomorrow

Presumably the op wants 3 hours sleep

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Ah okay my bad well to op I have not done chemistry in ages so would be useless for advice here but what I would say is go to sleep your not going to change the result much now for better or for worse. But if you lose sleep you won't be at your best in the exam

Reply 55

s4b3rt00th

if it makes you feel any better, i'm ****ed too.

Reply 56

Yorrick

Original post by Boy2001

Hi what do you mean by 'metals as structural materials'? Alloys or the properties of different metals (copper, aluminium etc) or something else? Thanks, your help is much appreciated

Pure metals are too soft because their atoms are all lined up, so putting force on one would make the whole layer move. This is why metals are malleable.

Alloys need to be used to make structural materals - they are mixtures of metals and since the atoms are different sizes, they disrupt the layers, make it harder for them to slide over each other and so they are harder.