2016 AQA Chemistry C2 - Unofficial Mark Scheme 2016

Reply 20

Certified

9

Original post by Naco88

I put because they were less reactive.

My mistake, didn't look at my reactivity series :frown:

Reply 21

Brewah

2

Mean Question: 5.75 degrees celsius (2 marks)

Apparatus Question: Digital thermometer, more accurate (2 marks)

Trends of graph Question: Describe trend of graph, value goes up and how it stops (3 marks)

Reversible reaction Question: Endothermic (1 mark)

Percentage question: 82.4% (rounded up) (3 marks)

Neutral pH question: pH = 7 (1 mark)

Neutralisation equation: H+ + OH- = H2O (1 mark)

*??? question???* Aluminium chloride (1 mark)

6 mark question: 200kg, explain why using graphs (6 marks)

subatomic particles question: 8 protons 8 neutrons (2 marks)

Isotope question: Define an isotope, talk about neutrons and protons (3 marks)

Electronic structure: two bonded pairs, 2 lone pairs of electrons (2 marks)

what type of bonding? covalent bonding (1 mark)

why do they not conduct electricity? no overall charge (1 mark)

nano particles question: 1-100nm (1 mark) *probably wrong*
nano particles have greater surface area (1 mark) *probably wrong*

Cloudy solution question: precipitate sulfur formed, solid and insoluble (2 marks)

Rate of reaction question: rate of reaction increases, more kinetic energy, frequent collisions, activation energy (4 marks)

Change the investigation question: change concentrations of acid (1 mark)

That's all i remember...

(these are NOT 100% correct, I may be wrong, its just brief notes from what i remember putting)

Reply 22

thecomputernerd

2

7ph was there somwehere

Reply 23

TappoWappoS

The last question was about thermosetting and thermosoftening polymers and I think the answer is that thermosetting polymers don't melt when they are heated because they contain cross links, but thermosoftening polymers do as they don't contain cross links. This means that the thermosoftening polymer would be impractical to use in the frying pan handle because it would melt. ☺️

Reply 24

jackbarry1999

2

For the percentage by mass I put 82% will this still b right because the next number was .3 so I just rounded down

Reply 25

Rebqqq

For the farm question I put 175 will I get zero marks

Reply 26

username2407683

6

Original post by Rebqqq

For the farm question I put 175 will I get zero marks

No, if you have justified why, you will get marks.

Reply 27

thecomputernerd

2

last q: thermosetting is better as it requires more energy, due to stronger intermolecular forces and cross links, has a high melting point, whereas thermosoftening has no cross links and has weak intermolceular forces

Reply 28

username2407683

6

Original post by thecomputernerd

7ph was there somwehere

The pH of 7 was quite early on in the paper and yes, it was the answer to the question about the pH of a neutral substance.

Reply 29

Naco88

OP

8

Original post by Brewah

Mean Question: 5.75 degrees celsius (2 marks)

Apparatus Question: Digital thermometer, more accurate (2 marks)

Trends of graph Question: Describe trend of graph, value goes up and how it stops (3 marks)

Reversible reaction Question: Endothermic (1 mark)

Percentage question: 82.4% (rounded up) (3 marks)

Neutral pH question: pH = 7 (1 mark)

Neutralisation equation: H+ + OH- = H2O (1 mark)

*??? question???* Aluminium chloride (1 mark)

6 mark question: 200kg, explain why using graphs (6 marks)

subatomic particles question: 8 protons 8 neutrons (2 marks)

Isotope question: Define an isotope, talk about neutrons and protons (3 marks)

Electronic structure: two bonded pairs, 2 lone pairs of electrons (2 marks)

what type of bonding? covalent bonding (1 mark)

why do they not conduct electricity? no overall charge (1 mark)

nano particles question: 1-100nm (1 mark) *probably wrong*
nano particles have greater surface area (1 mark) *probably wrong*

Cloudy solution question: precipitate sulfur formed, solid and insoluble (2 marks)

Rate of reaction question: rate of reaction increases, more kinetic energy, frequent collisions, activation energy (4 marks)

Change the investigation question: change concentrations of acid (1 mark)

That's all i remember...

(these are NOT 100% correct, I may be wrong, its just brief notes from what i remember putting)

Thanks! I will update this later. I have to be afk for 20 or so minutes.

Reply 30

Brewah

2

Original post by Naco88

Thanks! I will update this later. I have to be afk for 20 or so minutes.

No problem :smile:

hope its all correct haha, I got most the ones near the end correct too i think but I cant remember the questions.

Reply 31

hello654321

16

I swear it wasn't aluminium chloride it was ammonium chloride

Reply 32

SO597

1

Original post by jackbarry1999

No it's because it's more reactive

No, it is because hydrogen is lower down in the reactivity series than magnesium is - thus making hydrogen less reactive and therefore to be attracted to the cathode over the magnesium ions

Reply 33

Moustafa123r

6

Original post by noor.m

Okay so for the why is it cloudy question I wrote precipitate at first but then wrote about precipitation, would I still get the mark? :frown:

and also, for the change question I wrote a stopwatch?

I think u need to put because sulphur is produced as a solid and this block the view or makes it turn to cloudy

Reply 34

WillCrowe00

2

Original post by Brewah

Mean Question: 5.75 degrees celsius (2 marks)

Apparatus Question: Digital thermometer, more accurate (2 marks)

Trends of graph Question: Describe trend of graph, value goes up and how it stops (3 marks)

Reversible reaction Question: Endothermic (1 mark)

Percentage question: 82.4% (rounded up) (3 marks)

Neutral pH question: pH = 7 (1 mark)

Neutralisation equation: H+ + OH- = H2O (1 mark)

*??? question???* Aluminium chloride (1 mark)

6 mark question: 200kg, explain why using graphs (6 marks)

subatomic particles question: 8 protons 8 neutrons (2 marks)

Isotope question: Define an isotope, talk about neutrons and protons (3 marks)

Electronic structure: two bonded pairs, 2 lone pairs of electrons (2 marks)

what type of bonding? covalent bonding (1 mark)

why do they not conduct electricity? no overall charge (1 mark)

nano particles question: 1-100nm (1 mark) *probably wrong*
nano particles have greater surface area (1 mark) *probably wrong*

Cloudy solution question: precipitate sulfur formed, solid and insoluble (2 marks)

Rate of reaction question: rate of reaction increases, more kinetic energy, frequent collisions, activation energy (4 marks)

Change the investigation question: change concentrations of acid (1 mark)

That's all i remember...

(these are NOT 100% correct, I may be wrong, its just brief notes from what i remember putting)

I think it was ammonium chloride rather than aluminium chloride. I think the question was what salt is formed when ammonia and hydrochloric acid react together. Also, on the nanoparticle question, it asked about the size of nanoparticles in relation to atoms so I put that atoms are smaller than nanoparticles as well as that nanoparticles have a diameter of 1-100nm. I think you're right about the surface area bit though.

(edited 7 years ago)

Reply 35

Gcseggw

5

6a) Copper atoms/ions have free delocalised electrons that can flow and move throughout the structure, which can carry a charge. [2 or 3 marks]
6c) Thermosetting get harder and do not break under heat as the cross links between chains hold them together and are strong, whereas thermosoftening polymers have weak intermolecular forces so melts easily under a small amount of energy applied (supplied by the heat from the saucepan). [2 marks]

Reply 36

Moustafa123r

6

For the 6ix marks i put 190 kg do i still get marks for it

Reply 37

louisaah

12

I didn't even notice there was a question that went "after neutralisation what was the ph" LOL but I think it's 7, not 0. Because 7 is the neutral pH and just... look in your cgp book I think I'm correct