AQA GCSE Chemistry C1 Unofficial Markscheme 2017

No.	Question	Answer	Marks
1)a)i)	Why is atomic number the same?	Same number of protons	1
1)a)ii)	Why is mass number different?	Different number of neutrons (an isotope)	1
1)b)i)	How many elements in H2SO4?	3	1
1)b)ii)	How many atoms in H2SO4?	7	1
1)c)	Tickboxes	319 and 36 (bottom box)	1
1)d)	Describe the changes when copper carbonate reacts with sulphuric acid	Copper sulphate forms, size decreases, limewater turns cloudy, effervescence (bubbles)	3
2)a)i)	Draw the electronic structure of carbon	2 on inner shell, 4 on outer	1
2)a)ii)	Complete the sentance	Center part called the nucleus, contains 6 positive electrons	3
2)b)	What is a hydrocarbon	A compound made from hydrogen and carbon molecules	1
2)b)	Complete the ethane and ethene molecules	Just search these up	2
2	Describe the trend seen in the table	Alkanes with more carbons have higher boiling points	1
2	Compare boiling points of alkanes and alkenes	Both increase as number of carbon atoms increases, but alkenes have a lower boiling point than the equivalent alkane	2
2	Describe what happens to alkane molecules (diagram of cracking)	Alkane molecules thermally decompose when passed over a hot catalyst, and break down into smaller chain alkanes and alkenes, this is called cracking	3
3	What are the environment impacts of quarrying, drilling and producing calcium oxide?	Quarrying and drilling - Scars landscape, destroys habitats, noise and dust pollution, Carbon dioxide - Greenhouse effect and global warming, Particulates - Breathing difficulties and global dimming, Sulphur dioxide - Acid rain	6
4	What is polymerisation?	Many monomers bond/join to form large polymers	1
4	How has the number of plastic bags used changed from 2006-2014?	Decreased rapidly from 2006-2009, increased slowly from 2009-2014	2
4	Why does the mass of plastic bags not followed this trend?	Decrease in thickness/size of bags, lower density polymers used	2
4	Why better not to use landfill?	Saves space, polymers not biodegradable, prevent habitat destruction	2
4	Why better to recycle?	Conserves resources; uses less energy; quicker to meet increasing demand	2
5	Why isn't the Miller-Urey proof of how life formed?	Scientists weren't around at the time, could only produce glycine, the simplest, gases that were in the early atmosphere were not included	1
5	Why has the amount of CO2 reduced?	Dissolved/sequestered in oceans, absorbed by plants in photosynthesis, locked up in sedimentary rocks/fossil fuels	3
5	Which gases will not have condensed at -200 degrees Celsius?	Neon and helium	1
5	Why is CO2 removed before the process starts?	It would be solid at -200 degrees Celsius and would block up pipes	1
5	Which gas comes out with oxygen and why?	Argon because it has similar boiling point so would evaporate at almost the same time	2
5	Stage 1 - Cast iron reacted with oxygen, Stage 2 - Mixed with other metals, Explain the stages.	Stage 1 - cast iron is oxidised to remove carbon and make it less brittle/more ductile, Stage 2 - Mixed with other metals to make alloys, stronger as disrupts regular structure of metal atoms	4
6	How does an oil/water emulsion work?	Emulsifier molecule has hydrophilic head and hydrophobic tail. Hydrophilic head dissolves in/is attracted to water; hydrophobic tail dissolves in/is attracted to oil. When shaken forms a stable suspension as negatively charged heads repel and cause oil droplets to disperse evenly	4
6	Describe the changes in colour of bromine water when an alkene is added	Orange to colourless as alkenes are unsaturated hydrocarbons	2
6	Describe the process of hardening vegetable oils	Double bonds opened up, plant oils become saturated, melting point increases, solid at room temperature, spreadable	3
		Total Marks	60

(edited 6 years ago)

Reply 1

Ella324242

2

What do you think the 6 marker will be

Reply 2

trickytrichster

4

https://www.tes.com/resources/search/?authorId=2945540

^this guy has some AMAZING resources for C1, C2, B2, B3 :smile:

Reply 3

Lightdan

10

Original post by trickytrichster

https://www.tes.com/resources/search/?authorid=2945540

^this guy has some amazing resources for c1, c2, b2, b3 :smile:

thank you

Reply 4

Lightdan

10

https://drive.google.com/drive/folders/0B_BdBovu2jt6TS1GdFFjdVhXT1k?usp=sharing

Added some chemistry resources here xx

Reply 5

nsyed4962

Original post by Lightdan

https://drive.google.com/drive/folders/0B_BdBovu2jt6TS1GdFFjdVhXT1k?usp=sharing

Added some chemistry resources here xx

So useful thank you! :smile:

Reply 6

samhunt1

OP

5

Original post by Lightdan

https://drive.google.com/drive/folders/0B_BdBovu2jt6TS1GdFFjdVhXT1k?usp=sharing

Added some chemistry resources here xx

Really good stuff

I would also recommend the apps that go with the CGP revision guides, I find them really useful especially when we are this close to the exam

Reply 7

Apie215

8

I'm just going through pastpapers and reading the key words in markschemes

Reply 8

Chienmkiufdshn

1

sorry but when you click on the link for the chemistry unofficial markscheme 2017 nothing happens so can you please post it ASAP thanks 😜

Reply 9

isaac036

1

I think the 6 marker will be on FRACTIONAL DISTILLATION

- Larger molecules have higher boiling points so they are stored at the bottom
- Smaller molecules (petrol, biodiesel) are more volatile/flammable so they are stored at the top
- Liquids evaporating in to gases

idk wat else to put

Reply 10

TheAlchemistress

22

I have a feeling that either fractional distillation will come up or wegners theory.

(edited 6 years ago)

Reply 11

JewFromTheHood

1

Original post by Lightdan

https://drive.google.com/drive/folders/0B_BdBovu2jt6TS1GdFFjdVhXT1k?usp=sharing

Added some chemistry resources here xx

Woah, thanks!

Reply 12

perfectlywrecked

8

Original post by isaac036

I think the 6 marker will be on FRACTIONAL DISTILLATION

- Larger molecules have higher boiling points so they are stored at the bottom
- Smaller molecules (petrol, biodiesel) are more volatile/flammable so they are stored at the top
- Liquids evaporating in to gases

idk wat else to put

I guess something along the lines of:
-Crude oil is heated and vaporised and passed through a fractionating column
-Different fractions are tapped off at different levels where they condense
- Long chain hydrocarbons (Oil, diesel) condense at the bottom of the column. These fractions have a higher viscousity, are less volatile (evaporate at a higher temperature) and are less flammable.
-Short chain hydrocarbons (the opposite of longchain hydrocarbons: less viscous, more volatile and are more flammable.
Has everyone forgotten about the miller urey experiment? I feel it's going to come up, but then again I might be wrong.

Reply 13

GCSE student 17

1

I think the 6 marker would be on
The advantage and disadvantage of limestone products
Fractional distillation
Emulsions

Reply 14

samhunt1

OP

5

Original post by Chienmkiufdshn

sorry but when you click on the link for the chemistry unofficial markscheme 2017 nothing happens so can you please post it ASAP thanks 😜

I can only post it after the exam when we can collaborate and compare results, unfortunately I don't know the answers.😓
You need to revise all of C1, good luck 👍👍

Good luck everyone 👍

Original post by isaac036

I think the 6 marker will be on FRACTIONAL DISTILLATION

- Larger molecules have higher boiling points so they are stored at the bottom
- Smaller molecules (petrol, biodiesel) are more volatile/flammable so they are stored at the top
- Liquids evaporating in to gases

idk wat else to put

You need to put the following to get full marks.

1. Crude oil is heated
2. The hydrocarbons are vaporised
3. The column is hotter at the bottom which is cooler than the bottom
4. The vapours condense
5. They condense at different boiling points where they are separated / tapped

Reply 17

Tr0picalgaming

8

6 marker I guess will be
-comparing data eg advs and dis of limestone and they will give you a bit of info and say use your own resources too
-Continental drift/Primordial Soup
-Fractional Distillation
-Emulsions

Also think cracking will come up as teacher said it is a big topic and hasn't come up for a while

Good luck :smile:

Reply 18

GCSE student 17

1

The 6 marker was on the environmental impacts of Limestone
also Alkenes and Alkenes was on there
the Structure of the earth question was that diameter of the core was 7000km and the surface of the crust had a radius of 6400km
the answer should be
7000km/2= 3500km
6400km-3500= 2900km

(edited 6 years ago)

Reply 19

JackMoseley

15