Chemistry Predictions/Thoughts (2 Viewers)

[BionicMango]

bro please can someone post the catalyst sols

Tywebb posted them a while ago, check page 20-21

 

[nowomansland]

Yeah it’s a weird one, made me think as well and I’m definitely not 100% sure about this but basically the the keq only changes if the temperature changes, which would only change if someone added an EXTERNAL change in temperature. And if the concentrations of everything is still the same then the keq is still the same so the temperature has to be the same.

Think of it in terms of collision theory - sure more particles are bumping into each other, more of those are actually with the inert gas which it won’t react with, so in the end there is no net effect.
Remember PV=nRT? Because n increases, pressure increases, so it stays balanced WITHOUT a change in temperature. No change in temperature and no change in concentrations means no change in Keq

wait so what happens to the extra pressure? the system just does nothing abt it?

 

[C_master]

I got D for 19. The solution is being diluted so pH goes towards 7. And it’s not a acid/conjugate pair so it’s not a buffer system.
For 20 I got B as well

really?

 

[BionicMango]

wait so what happens to the extra pressure? the system just does nothing abt it?

Nothing happens, the concentrations of the gases are still the same and so is the temperature

 

[nowomansland]

I got D for 19. The solution is being diluted so pH goes towards 7. And it’s not a acid/conjugate pair so it’s not a buffer system.
For 20 I got B as well

someone said it was a buffer system

 

[C2H6O]

My pred for last q: ”A polymerisation titration was conducted using chloroethene chlorinated using a chlorine solution whose concentration was firstly determined by conductometric back precipitation titration. If avg titre volume was 2mL (1sf btw), calculate the amount of Iron thiocyanate indicator added during the first titration. Then with reference to the mass spec provided and socioculturalenviroeconomic factors, evaluate this method’s effectiveness in modelling Aboriginal people’s understanding of saponification.” (12 marks)

hey at least i clipped aboriginal saponification and ppt titration

 

[BionicMango]

really?

A conjugate pair is required for a buffer isn’t it

Edit: wait nvm, because of the equilibrium between acetate and acetic acid?

 

[LittlePig107]

"The addition of argon gas increases the pressure... bla bla bla"

By transforming the equation into 2NO2(g) <-> N2O4(g) + Heat , it becomes clear what happens

ts is wrong

 

[C2H6O]

A conjugate pair is required for a buffer isn’t it

is that the acetate plus hcl? i thought thats cause theres half moles of hcl to acetate so half of acetate gets protonated so buffer so ph=pka or whatever i lowkey forgot what the question was

 

[nowomansland]

A conjugate pair is required for a buffer isn’t it

Edit: wait nvm, because of the equilibrium between acetate and acetic acid?

yes

 

[BionicMango]

is that the acetate plus hcl? i thought thats cause theres half moles of hcl to acetate so half of acetate gets protonated so buffer so ph=pka

Yeah I realised they aren’t conjugate pairs directly, but the products + reactants together DO form a conjugate pair between a weak acid and weak conjugate base, so I’m wrong,

 

[C2H6O]

guys wtf i swear this was the least straightforward out of the past hscs
ive never left and figured out one let alone so many trick questions that i missed while marking
i mightve thrown really hard

 

[LittlePig107]

19 is 100% D, you can calculate the Ka of the acid and figure it out

 

[nowomansland]

guys wtf i swear this was the least straightforward out of the past hscs
ive never left and figured out one let alone so many trick questions that i missed while marking
i mightve thrown really hard

yeah i thought did good but realised the questions were trickier than i thought

 

[BionicMango]

19 is 100% D, you can calculate the Ka of the acid and figure it out

What is the Ka, and how do you find it? We don’t have the equilibrium concentrations?

 

[C2H6O]

19 is 100% D, you can calculate the Ka of the acid and figure it out

but i did a calculation initially before realising it was a buffer and got like 4.809...?

 

[C2H6O]

guys wtf i swear this was the least straightforward out of the past hscs
ive never left and figured out one let alone so many trick questions that i missed while marking
i mightve thrown really hard

there were so many trick questions this year its diabolical
they weren't hard ill admit but you had to see it...

 

[C_master]

idk I got 19 C and many other people did so im sticking to that
hopefully the official sols out soon

 

[eternallyboreduser]

idk I got 19 C and many other people did so im sticking to that
hopefully the official sols out soon

19 is def c, i got d idek i realised it was a buffer but i had no time left

 

[LittlePig107]

What is the Ka, and how do you find it? We don’t have the equilibrium concentrations?

nah you do have the equilibrium concentrations cause you know the pH initially so you can figure out how much acetic acid there is and how much acetate there is