HSC Chemistry Question Thread

[nibblez16]

How do we calculate TDS?

[MysteryMarker]

What is the range in which the titres of a titration can range from? Like what is the maximum difference in volume between titres before it has to be omitted?

Cheers.

[RuiAce]

How do we calculate TDS?

You just have to use common sense.

The dissolved solids are the ones actually dissolved. Not the ones picked up by the filtration.
So whatever was left from evaporation.


Then you just find your concentration as a %(w/v)

[RuiAce]

What is the range in which the titres of a titration can range from? Like what is the maximum difference in volume between titres before it has to be omitted?

Cheers.

What do you mean? Do you mean to find the average titre volume?

Because if you mean that then by common sense you shouldn't even be touching data off by more than 0.20mL

No "defined number". Just use common sense

[bethjomay]

How does this look as a plan for an ethanol 7 marker? (I took your advice Jake ) Sorry if it's hard to read. I've put (eq.) where I would put a relevant equation!

[jakesilove]

What is the range in which the titres of a titration can range from? Like what is the maximum difference in volume between titres before it has to be omitted?

Cheers.

Three values need to be within 0.1mL of each other

[jakesilove]

(Image removed from quote.)

How does this look as a plan for an ethanol 7 marker? (I took your advice Jake ) Sorry if it's hard to read. I've put (eq.) where I would put a relevant equation!

Looks fucking brilliant. Just make sure to have a final assessment, and you're sweet

[bethjomay]

Looks fucking brilliant. Just make sure to have a final assessment, and you're sweet

Yay thank you! Ah yes, I always forget that.

[wesadora]

why does 1 butanol have higher mp/bp than 2 butanol? Is it because there are hydrogen bonding (OH) is on the first carbon, or has more polarity?

[jakesilove]

why does 1 butanol have higher mp/bp than 2 butanol? Is it because there are hydrogen bonding (OH) is on the first carbon, or has more polarity?

No idea, and that definitely isn't something you need to know

[wesadora]

No idea, and that definitely isn't something you need to know

LMAO GOOD :'D

[MysteryMarker]

Explain why Arrhenius acid/base definition is unable to account for the acid/base properties of NaHCO₃, whereas the Bronsted - Lowry theory can.

Is this just because NaHCO₃ amphiprotic? So when it dissolves in water it can either produce H⁺ or OH^-, and thus he can't define it as an acid/base. Or is there more to it?

Cheers.

[jakesilove]

Explain why Arrhenius acid/base definition is unable to account for the acid/base properties of NaHCO₃, whereas the Bronsted - Lowry theory can.

Is this just because NaHCO₃ amphiprotic? So when it dissolves in water it can either produce H⁺ or OH^-, and thus he can't define it as an acid/base. Or is there more to it?

Cheers.

That sounds right to me!

[tennis1]

Ok so I'm just a little bit confused about the effect of errors on overall concentration or percentage in a tablet

* rinsing all glassware with water: dilutes--> Decreases conc in burette. so does that mean that more ___is added to burette? and then overall conc. will increase? percentage mass decrease?

*not drying Na2CO3= More water-->Dilutes conc.--> more __ added into the burette-->? more concentrated overall (final calc)??

* wrong indicator: will mean colour change doesn't match equivalence point and so more___ added in burette? Increasing concentration?

Thanks!

[nickglyn]

Hey guys, is the answer to this C? I can't find the answers to this paper online it's too old. Thanks