OCR A Level Chemistry - Paper 1 Physical 5th June 2018 Unofficial Markscheme

Anyone get 22.5 for the value of k?

What did people get for the oxide of chlorine one? I got an mr of 142.4 I think and CoClO4 but I was so confused so it’s probs wrong 😂

Was a pretty nice paper, some answers i got below. Please add to this so we can form an accurate MS:

Multiple Choice:


Extended Answer Questions:
16.
* The enthalpy change that accompanies the dissolving of 1 mole of gaseous ions in water to form 1 mole of aqueous ions.
* Cycle constructed
* -927/2 = = -463.5 (as 2F-)
* F- has a more exothermic hydration enthalpy as smaller ionic radius so stronger attraction with water molecules.
* +158 bond enthalpy for F-F



Cl2O7 for formula of liquid A.
RbIO3 for compound.
95.9% for NaOH in Bleach.
1.02 mol for Kc
0.477% dissociates



Final Question:
C = Trans of [Cu(NH3)4(H20)2]
D = can't remember
E = Cu
F = Cu(NO3)2 . 3H2O

http://www.docbrown.info/page06/molecule_shapes2.htm

Like this

I got 2.5 for 1/T when I drew the line, so it would be 2.5/10^-2 (or 2.5x10^3) ? Were you meant to take away 83 from 100 for T for the pv=nrt question?

wtf you can't just do that.



I was thinking this, it's gonna suck if this was the answer and i didn't write it. I didn;t think iron could react with itself to form 2 ions

Hey! I think I got something like -1008 for the enthalpy of hydration one :/ Not sure about the answer though.

Nooooooo! Loooking at this is sooo depressing actually

I hope grade boundaries are soooo low completely messed up the hydration and average bond enthalpy question..as well many of the others ...and I really need an A fml

Yes is that wrong? 😭

I got 7480 for the activation energy since my gradient was 900, do you think that will still get the marks?

Did I get it wrong? ~~~~ Does anyone know the value of T for that pv=nrt question or were you even meant to use pv=nrt?

D was CuSo4
I got Ea of + 6650Jmol-1 (from m = -800)
Pka = 4.76
Hydration enthalpy -504

Did anyone get Cl3O2 because I thought pV=nRT wasn’t required as it was 100kPa and it was just a change of state as it boils at 83 Celsius? So 0.445g produced 0.076/24 mols of gas.

Yh I got exactly the same my Ea was roughly around yours. Definitely -504 for hydration enthalpy.