Edexcel A2 Chemistry 6ch04/05 JUNE 2015

thanks so much i've repped you recently so TSR dont let me rep you!! Anyway i'm done with this revision! good luck man!

Hey what tips would u guys give for me on the titration questions like the Ag one in the 2012 paper?

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4.4 g)ii talks about ethanoic acid and ammonium carbonate. in this reaction,entropy change of the system is positive, since carbon dioxide gas (which is more disordered than the aqueous reactants) is produced. Additionally, the number of product molecules is greater than the number of reactant molecules, further increasing disorder.4.4 g)iii talks about exothermic reactions and the production of a solid, e.g.2Mg + O2 --> 2MgOA solid (MgO) is being formed from a gas (O2), so the entropy change of the system is negative, as the molecules are becoming more ordered. Additionally, two molecules have been produced from three, further decreasing disorder.For exothermic reactions, entropy change of the system is always likely to be negative, since these are reactions which release heat (therefore the system itself cools, and so disorder decreases).

Does anyone know if we can do graphs in pencil?

Does anyone know if we can do graphs in pencil?

Yea just press hard enough


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Can someone please explain why when the same Kc equation has every concentration halved then Kc= (Kc)^1/2???

I thought only temp affects Kc position


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I'm getting 13.3, but the mark scheme says it should be 13.6

there are 2 hydroxides so times the concentration by 2

there are 2 hydroxides so times the concentration by 2

do we need to know anything about dilution of an alkali ?

Oh and if it was say, H2SO4 for example, would we multipy the concentration by 2 when finding the pH for it as well?