The Student Room Group
Reply 1
i know the question. i have the mark scheme. its a ridiculous answer. i'll find it
Reply 2
HCl react with water (give you 1 mark)!!!!!! - wtf?
to form ions which are hydrated/bonded with water (gives you second mark)

jan 2003 q2ii - C1
Reply 3
Sounds about right:

HCl+H2OH3O++ClHCl + H_2O\Rightarrow H_3O^+ + Cl^-
Reply 4
yes but using the word reacts? what about using the term dissociate? saying that the enthalpy of dissociation is less than the enthalpy of hydration and that is why it's soluble? or have i used that term dissociate incorrectly.
Reply 5
RMIM
yes but using the word reacts? what about using the dissociate? saying that the enthalpy of dissociation is less than the enthalpy of hydration and that is why its soluble? or have i used that term dissociate incorrectly.


That's A2 material. At AS it is sufficient to say that HCl and H2O react as in the equation I gave above.
Reply 6
well yes, you gave an equation - you worked for the 2 marks. but look at the mark scheme I posted - to me saying 'they react' does not seem like an answer worth a mark.
Reply 7
rofl stupid chemistry examiners as usual..
Reply 8
That's true, but stuff about enthalpy of solution and all that crap doesn't come in until A2 and probably would not be credited in an AS paper. Oh, and how is giving that equation really work? If you don't know that before sitting an AS exam, you may as well not bother...
Reply 9
Danielisew
rofl stupid chemistry examiners as usual..

that's nothing - you should really study mark schemes, u have to be really careful sometimes.

steamy fumes get you the mark. steamy white fumes get you zero.
there are some nightmare of answers for enthalpy questions to do with E.A.
Reply 10
IChem
Oh, and how is giving that equation really work?

i was comparing your equation and writing down 'it reacts' - but perhaps im underestimating the words 'it reacts' - I think we use it in a similar fashion when talking about NaOH with AL2O3, Fe2O3 and SiO2
Reply 11
Spose.
Reply 12
Oh come on.. the chemistry examiners are absolute .. u know.
They change every standard answer every year so it is impossible to get it right. They also have some ridiculous answers that give you the mark and then say DO NOT ALLOW: *insert scientific correct answer here*

They are just ridiculous and most other subjects even for Edexcel do not have as harsh mark schemes.. The chemistry mark schemes really are annoying. You can go into that exam knowing everything but still drop 3 marks or more simply because the mark scheme has a stupid answer or different from past years.. How can you simply change answers and expect people to know the new correct one? Yes, there are limited things to ask in chemistry, but at least chuck in a few impossible to know equations that we can try rather than changing standard answers..

The examiners just piss me off and my class and teacher..
Reply 13
Danielisew
Oh come on.. the chemistry examiners are absolute .. u know.
They change every standard answer every year so it is impossible to get it right. They also have some ridiculous answers that give you the mark and then say DO NOT ALLOW: *insert scientific correct answer here*

They are just ridiculous and most other subjects even for Edexcel do not have as harsh mark schemes.. The chemistry mark schemes really are annoying. You can go into that exam knowing everything but still drop 3 marks or more simply because the mark scheme has a stupid answer or different from past years.. How can you simply change answers and expect people to know the new correct one? Yes, there are limited things to ask in chemistry, but at least chuck in a few impossible to know equations that we can try rather than changing standard answers..

The examiners just piss me off and my class and teacher..


Wait for A2, fun fun fun with equations for transition metals, period 3 and group 4 as well as the necessity to manipulate various mathematical equations for equilibrium constants, thermal decomposition, pH, activation energy (the Arrhenius Equation) and buffer solutions (The Henderson-Hasselbalch Equation): I'd say that'd do it.