that acid 1 acid 2 question (3 Viewers)

[ashllis92]

^ same,
isnt phenolpthalein between 7.5 - 9

Eh, close enough, I think they won't mind too much if the figures aren't exact just that I got the general gist

 

[megaman]

Something to the effect of it changes colour at pH 8-10 which was at the equivalence point of both curves .: it could accurately identify the end points

Ok do you remember how many marks it was worth? Because I remember saying that it changes around a pH of 8 thus is a suitable indicator for the equivalence points in both graphs. I couldnt remember the exact endpoints ={

 

[ashllis92]

I think it was 2 but it sounds like you pretty much have it, you probably got the marks so don't worry

 

[boxhunter91]

I just said phenolpthalien was used because in both graphs the equivalence point is ph > 7

 

[megaman]

Cool thanks for that =)

 

[walk]

Acid 1 is strong (check equivalence point pH = 7))
Acid 2 is weak (EP pH = approx 9)

Acid 2 needed more KOH for neutralisation so it is more concentrated than Acid 1

You pick an indicator which has an end point colour change as close to the equivalence point pH as possible (phenolphthalien changes between 8-10 so usually used for a weak acid strong base titration) .......but because the change in pH for acid 1 titration occurs over such a small addition of volume (the volume difference between pH 7 and 9 is insignificant) ....the change in colour of the phenolphthalein will still indicate pretty accurately that you have passed through the equivalence point pH.

 

[random-1005]

what was the specific question?

was it something like "write a reaction with an acid similar to acid 1 and NaOH"

I wrote NaOH + HCl --> H2O + NaCl

I dont know if its right.....

vague and dodgy questions, have got to love board of studies.

just tell us what you want us to do and cut all the bullshit

 

[cheechthecheech]

Acid 1 is stronger with a higher deg of dissociation but acid 2 is more concentratrated. simple.

 

[imoO]

OMFG....another questions I screwed up..

I didn't write about concentrations....

Only about strong and weak acids

 

[4theHSC]

I think it was write the salt formed when KOH reacts with an acid like acid 2...
I wrote CH3COOK

Acid 1 was stronger but more dilute,,, btw I put KCH3COO, is that still right? lol

 

[Tronester]

By the shape of the titration curve for acid 2 could you assume it was diprotic? It started steep and then tapered off, not smooth like acid 1 suggesting two protons donated.

This would make it a strong, concentrated diprotic acid such as sulfuric?

 

[Aerath]

But acid 2 was 'weak', wasn't it?

 

[Tronester]

I remember it to have an original pH of around 1-2 and its equivalence point was also around 8 (for the phenophthalein qs). Wouldn't this also make it strong?

 

[chuboy]

I remember it to have an original pH of around 1-2 and its equivalence point was also around 8 (for the phenophthalein qs). Wouldn't this also make it strong?

Not necessarily, the only thing that makes an acid strong is if it completely dissociates. It's quite possible that a weak acid could have that pH.

BTW the question was Name the salt which forms when KOH is reacted with an acid similar to Acid 2.

In other words, give an example of a salt which forms between a weak acid and KOH.

Except they didn't want to tell you it was weak

 

[Michaelmoo]

For the salt question. I think it said name the salt.

In our trial, we had a question that also said name. They only accepted (say in this case) Potassium acetate. They didn't accept writing the formula, i.e. CH3COOK. Dono how it will work in the HSC though.

 

[Aerath]

For the salt question. I think it said name the salt.

In our trial, we had a question that also said name. They only accepted (say in this case) Potassium acetate. They didn't accept writing the formula, i.e. CH3COOK. Dono how it will work in the HSC though.

LOL, that'd be pretty epic, hahahaaha.

 

[Michaelmoo]

LOL, that'd be pretty epic, hahahaaha.

Yer lol. Lota people will get screwed if they do mark like that.

They got a point though. It didn't say identify, it said name. Lol.

 

[shady145]

For the salt question. I think it said name the salt.

In our trial, we had a question that also said name. They only accepted (say in this case) Potassium acetate. They didn't accept writing the formula, i.e. CH3COOK. Dono how it will work in the HSC though.

is that the answer... first off i had.... potassium X lol and then i decided to change it to potassium acetate

 

[ashllis92]

Acid 1 was stronger but more dilute,,, btw I put KCH3COO, is that still right? lol

Technically no but it depends on how picky they're going to be. Since the K adds on where the H left off the K needs to be on the O ie. CH3COOK but you certainly had the right idea, hopefully they'll give you the marks

 

[Aerath]

KCH3COO is just as valid as CH3COOK.