HSC OVERALL MARKS GOAL AND/OR REALISTIC PREDICTIONS (2 Viewers)

[nsw..wollongong]

WHERE DID THAT FORMULA COME FROM WITH THE PKA AND THE LOG(A/HA) UHHGHHGHGHGHGH IM SO LOST

IS THAT NOT HOW UR MEANT TO DO IT DID I MAKE THIS SHIT UP

 

[nsw..wollongong]

where tf did that sqaure root come from whats going on celiac

 

[SadCeliac]

IS THAT NOT HOW UR MEANT TO DO IT DID I MAKE THIS SHIT UP

oh its henderson hasselbalch but we never learnt how to use it lmao
i thought it was a shortcut method

 

[Unovan]

yo mb i got distracted but theres that q

 

[SadCeliac]

where tf did that sqaure root come from whats going on celiac

i was doing the [H+][A-]/[HA] and assumed that H+ conc = A- conc so I just let it be x^2 and solved for x (hence the square root)
just I did it in one step

 

[nsw..wollongong]

who is henderson

 

[SadCeliac]

View attachment 40236

yo mb i got distracted but theres that q

OH


OH MY GOD



WE GOT THE SAME ANSWER DLSKHDSFKHLDFSLKJHDFSLKJHDFSLKJDFS LETS GOOO

 

[nsw..wollongong]

i need to drop out of chem.

 

[Unovan]

OH


OH MY GOD



WE GOT THE SAME ANSWER DLSKHDSFKHLDFSLKJHDFSLKJHDFSLKJDFS LETS GOOO

i thought u were talking about the other q initially ngl

 

[SadCeliac]

i thought u were talking about the other q initially ngl

anyways im going to bed now as per my crazy sleep schedule (I say that im going to bed really im going to shower then sit on my phone)

 

[unofficiallyred12]

View attachment 40236

yo mb i got distracted but theres that q

this is not the correct approach tho, since Hclo4 is a weak acid [clo4]- is a weak base, thus Naclo4 is in fact a basic salt which u ignored in ur working

 

[SadCeliac]

this is not the correct approach tho, since Hclo4 is a weak acid [clo4]- is a weak base, thus Naclo4 is in fact a basic salt which u ignored in ur working

so how would you do it (send working please)

 

[nsw..wollongong]

this is not the correct approach tho, since Hclo4 is a weak acid [clo4]- is a weak base, thus Naclo4 is in fact a basic salt which u ignored in ur working

i giggled ngl tell him off

 

[synthesisFR]

so how would you do it (send working please)

I literally said it

 

[SadCeliac]

i cbf to send more

@Luukas.2 can you try q11 and send your working (since you're basically an sr for chem)

 

[synthesisFR]

In bed but it looks like the acid is in excess so some of it neutralises
So then it’s just a simple excess acid equilibrium with common ion effect question?

I LITERALLY SAID IT y’all don’t listen to me

 

[unofficiallyred12]

seems pre legit

 

[Luukas.2]

this is not the correct approach tho, since Hclo4 is a weak acid [clo4]- is a weak base, thus Naclo4 is in fact a basic salt which u ignored in ur working

I will go have a look but there is something wrong here.

Perchloric acid, HClO₄, is one of the 6 strong acids.

 

[unofficiallyred12]

ya but the question says it's not

 

[Luukas.2]

Ok, I've found Q11. It's wrong. Perchloric acid is a strong acid. It is stronger than nitric acid, sulfuric acid, and hydrochloric acid. It has a pK_a of around -15, so that the acid ionisation equilibrium has an equilibrium constant of around 10¹⁵.