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EDEXCEL GCSE Chemistry Paper 2 12th June 2019 Unofficial Markscheme

Reply 40

smith.214

8

Did you get 82.8 or something like that for the butane question? Also , ionic equation was water right?

Reply 41

IsMo987

12

Altogether how many marks were all the maths question

Reply 42

annonymous2003

10

Nah I doubt an 8 is gonna be 167/200 thats way to high. A lot of people in my school found both papers hard so i feel like the grade boundaries are gonna stay the same.

Reply 43

Quadrinomial

19

Original post by Dayo03

6.92 for lithium empirical formula

2.25 for mass on MgO

4 + (for the charge)

1x10^-7 for 100 nm

hydrobromic acid - when HBR dissolves in water

the table one was about halogen displacement reactions - iodine is less reactive so gets displaced

6 marker on collision theory :
Concentration: If there is more of a substance in a system, there is a greater chance that molecules will collide and speed up the rate of the reaction. If there is less of something, there will be fewer collisions and the reaction will probably happen at a slower speed.
Increasing the surface area of a solid reactant exposes more of its particles to attack. This results in an increased chance of collisions between reactant particles, so there are more collisions in any given time and the rate of reaction increases.

Nanoparticles do not leave a white mark on the skin - good for sunscreen
however, there hasn't been much research so we don't know long term effects

unsaturated means double bond so can still react with other elements as bond breaks up

in bromine water ethene turns it colourless , poly ethene no as it doesn't have a double bond

kerosene - used for aircraft

kerosene compared to diesel oil - easy ignition, less viscous, low boiling point etc

the one about the Molecular formula for CH2 was C6H12

Test for chlorine - blue ltmus paper turns red

1.5 x 10^21 for the avogadros contant question

Test for chlorine: you forgot that it bleaches white after turning red

Reply 44

IsMo987

12

What did people say about why lithium was less reactive than potassium

Reply 45

annonymous2003

10

Does anyone remember what exactly the carbon in butane question was?

Reply 46

Adedayo2003

14

Original post by Incarcarus

Test for chlorine: you forgot that it bleaches white after turning red

oh yhhh

Reply 47

Adedayo2003

14

Original post by falasow

Nah I doubt an 8 is gonna be 167/200 thats way to high. A lot of people in my school found both papers hard so i feel like the grade boundaries are gonna stay the same.

no way that's even too high for a 9, I think they'll stay about the same, maybe 150 - 154 for a 9

Reply 48

IDoNothingRight

8

Am I the only one who found that test pretty difficult? I most definitely did not get most of the 2 - 3 markers due to the fact they were based on such specific things that threw me off 😐

Reply 49

Quadrinomial

19

9 will probably be anywhere between 150-165

Reply 50

IsMo987

12

Is it correct if I wrote that lithium is less reactive because lithium is closer to the nucleus therefore it would be easy to gain electrons but potassium electrons are further away so there would be inner shielding of electrons and the attraction would be weaker so would be hard to gain electrons but easier to lose electons

Reply 51

Adedayo2003

14

Original post by IsMo987

Is it correct if I wrote that lithium is less reactive because lithium is closer to the nucleus therefore it would be easy to gain electrons but potassium electrons are further away so there would be inner shielding of electrons and the attraction would be weaker so would be hard to gain electrons but easier to lose electons

you got the first part right about it being close to the nucleus but this means that it's harder to lose the outer electron because there's a stronger force of attraction to the nucleus

Reply 52

annonymous2003

10

Ugh i just realised i got the correct answer for the isotope question 6.92 and did all the working out for it but then i wrote a different answer. Will I still get the marks? (I didn’t cross out my original working out)

Reply 53

IsMo987

12

Original post by Dayo03

you got the first part right about it being close to the nucleus but this means that it's harder to lose the outer electron because there's a stronger force of attraction to the nucleus

I also wrote that it would be harder to lose an electron

Reply 54

M. Matty

8

Lithium and Potassium are group 1 elements (Alkali Metals), with 1 electron in their outer shell. Therefore, they don't gain electrons, they LOSE 1 electron to form full outer shell.

You are correct in saying that the outer electron and positive nucleus distance is closer in Lithium than in Potassium. However, because Potassium has more occupied shells than Lithium, there is a weaker force of attraction, making it easier for the electron to leave the atom.

I believe it was like a 2-3 marker, so it's not too bad.

Original post by IsMo987

Is it correct if I wrote that lithium is less reactive because lithium is closer to the nucleus therefore it would be easy to gain electrons but potassium electrons are further away so there would be inner shielding of electrons and the attraction would be weaker so would be hard to gain electrons but easier to lose electons