Chemistry C1,C2,C3 - May 2014

Reply 40

S.Ahmad

10

Original post by Beefman10

I know most of these, just the odd ones whitch I need to learn. Thank you

Which ones?
Possibly I can help.

Reply 41

Beefman10

3

Original post by S.Ahmad

I'd definitely know the definitions and try to incorporate as many of them in your answers as possible, words such as:

•

Inter-molecular/electrostatic forces - the force on the particals in a structure.

•

Yield - eistmated yeild % final yield. × 100

•

Noble gas configuration - 8 electrons on the outer shell.

•

Giant Lattice

•

Covalent, Ionic and Metallic bonding

•

Exothermic, Endothermic. Exothermic, heat given out to the surroundings. Endothermic, heat taken in from the surrounds.

•

Neutralisation

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Oxidation, Reduction

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Thermal Decomposition

•

Delocalised electrons, Sea of electrons - in metals, the electrons are allowed to move around which is why they can conduct electricity.

•

Fullerenes (Buckminister and Nanotubes) tiny hexagon shaped particals. Fullerences can be used for drug deliver in humans and deogent. Nano tubes are very strong and is used for tennis rackets.

•

Malluable

•

Monomer

•

Conductor

•

Polymer

•

Shape memory alloys (Nitinal)

•

Low density/high density polyethene

•

Thermosoftening, Thermosetting

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Catalyst - speeds up the speed of a reaction. Can reuse it.

•

Activation energy - the minimum energy needed for a reaction

•

Surface area:volume ratio

•

Precipitation

•

Collision theory - the more frequently particals collide the more energy in a reaction. Can speed this up by heat, increasing the density. More surface area of particals.

•

Acids, bases and salts

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Effluent

•

Electrolyte - negative particals are attractive to positive electrolytes. And positive particals are attractive to negative.

•

Anode and cathode

•

Cryolyte

<\quote>

Correct me if any of them are wrong. I'm going to do another 2 hours of revision. 8 - 10 to make sure I've learnt all of them. Hopefully I will be alright.. :/ slightly worried.
Sorry for spelling mistakes. I'm on my phone at the moment.

Reply 42

Beefman10

3

Original post by S.Ahmad

Which ones?
Possibly I can help.

Ones above ^^

Good luck guys!

Any predictions on the 6 markers for C2?

Reply 45

S.Ahmad

10

Original post by Beefman10

•

Collision theory - the more frequently particals collide the more energy in a reaction. Can speed this up by heat, increasing the density. More surface area of particals.

Correct me if any of them are wrong. I'm going to do another 2 hours of revision. 8 - 10 to make sure I've learnt all of them. Hopefully I will be alright.. :/ slightly worried.
Sorry for spelling mistakes. I'm on my phone at the moment.

Collision theory is affected by Temperature, Concentration, Pressure and Surface area.

Reply 46

artymaniac

13

Original post by thechemistress

Determined to not **** up this exam after Biology's failure xD So yeah, hopefully it will go well. If anybody has some challenging C2 and C3 questions, please fire them at me now, thanks :biggrin:

substances found on Mars.
6 (b) (i) What is the purpose of gas chromatography?
...........................................................................................................................................
...........................................................................................................................................
(1 mark)
6 (b) (ii) What information do the molecular ion peaks from the mass spectrometer give about
the substances?
...........................................................................................................................................
(1 mark)
6 (c) The atmosphere on Venus contains droplets of sulfuric acid solution.
6 (c) (i) Suggest a pH value for sulfuric acid solution.
pH = ................................
(1 mark)
6 (c) (ii) Name the ion which makes sulfuric acid solution acidic.
...........................................................................................................................................
(1 mark)
6 (d) The atmosphere of Venus contains the isotopes 2
1H and 1
1H
Describe the similarities and the differences in the isotopes 2
1H and 1
1H
You should refer to the sub-atomic particles in each isotope.
...........................................................................................................................................
enjoy

Reply 47

Winading001

4

Original post by artymaniac

substances found on Mars.
6 (b) (i) What is the purpose of gas chromatography?
...........................................................................................................................................
...........................................................................................................................................
(1 mark)
6 (b) (ii) What information do the molecular ion peaks from the mass spectrometer give about
the substances?
...........................................................................................................................................
(1 mark)
6 (c) The atmosphere on Venus contains droplets of sulfuric acid solution.
6 (c) (i) Suggest a pH value for sulfuric acid solution.
pH = ................................
(1 mark)
6 (c) (ii) Name the ion which makes sulfuric acid solution acidic.
...........................................................................................................................................
(1 mark)
6 (d) The atmosphere of Venus contains the isotopes 2
1H and 1
1H
Describe the similarities and the differences in the isotopes 2
1H and 1
1H
You should refer to the sub-atomic particles in each isotope.
...........................................................................................................................................
enjoy

I would not describe that as challenging. I would suggest that you bring up the example of the planning question which was on the June 2013 paper. (Question 2)

(edited 9 years ago)

Reply 48

Somegirl123

Guysss, do you have any idea what grade 38/60 is for C2 higher AQA. Just a rough idea would be great. Thanks

Reply 49

artymaniac

13

Original post by Winading001

I would not describe that as challenging. I would suggest that you bring up the example of the planning question which was on the June 2013 paper. (Question 2)

Well it was the last question on the paper which is generally one of the hardest .. but I guess it depends on what your idea of challenging is..

Reply 50

Simpliey

I'm sitting CHEM1 and CHEM2 :smile:

Reply 51

Winading001

4

Original post by artymaniac

Well it was the last question on the paper which is generally one of the hardest .. but I guess it depends on what your idea of challenging is..

For me, the last question on the paper was not that challenging.

Reply 52

scott_the_noob

Original post by BobThomas3

Thanks, more specifically the questions asking 'how can you improve the results of this experiment?' (OWTTE)

A good generic statement is "intoduce more intervals" but only for some questions.

Reply 53

charlottejyp

13

Can someone very quickly explain how changes in pressure affect equilibrium and amount of product produced? Thanks :biggrin:

Posted from TSR Mobile

Reply 54

interstitial

OP

18

Original post by charlottejyp

Can someone very quickly explain how changes in pressure affect equilibrium and amount of product produced? Thanks :biggrin:

Posted from TSR Mobile

Pressure only has an effect on gaseous reactions.

An increase in pressure shifts the equilibrium to the side with less moles of gas by Le Chatelier's principle, in order to minimize the overall change in pressure of the system. In the case of the Haber process (

\text N _2 + 3 \text H _2 \longrightarrow 2 \text{NH} _3

), the right side has less moles of gas, so an increase in pressure would cause the equilibrium position to shift to the right and increase the yield of ammonia.

Decrease in pressure does the opposite.

Posted from TSR Mobile

(edited 9 years ago)

Reply 55

charlottejyp

13

Original post by majmuh24

Pressure only has an effect on gaseous reactions.

An increase in pressure shifts the equilibrium to the side with less moles of gas by Le Chatalier's principle, in order to minimize the overall change in pressure of the system. In the case of the Haber process (

\text N _2 + 3 \text H _2 \longrightarrow 2 \text{NH} _3

), the right side has less moles of gas, so an increase in pressure would cause the equilibrium position to shift to the right and increase the yield of ammonia.

Decrease in pressure does the opposite.

Posted from TSR Mobile