chemistry tricks students

MB44

Im pretty good at chemistry but i am worried that there are going to be really abstract questions this year. last yr a question was asked on the paper and it took me an hour to find the answer, it ended up to be in the one word in a 400 page book. any one have any thoughts on this . Also all predictions are welcome. Im hoping for water of recrystalisation, clove experiment and tests for anions.

Matthewthebig

what was last years question?

MB44

name the series of coloured lines in the line emission spectrum of hydrogen corresponding to transitions of electrons from higher energy levels to the second energy level

d4gurl

that would be the balmer or lymann series?hmm which one cnt remember!

Zoodlebop

I think that it's the lymann series, right. We have paschen, lymann and balmer on our course and balmer is from high E-level to lowest. I think it is lymann.

DiscoMouse

Balmer is the only one of the three we need to know, I think.

My only issue is with the titrations- there's just so much protocol and precaution in the whole thing, I always end up leaving something out. Hoping for lots of organic chemistry!

Matthewthebig

Balmer. it's standard text ffs

CrimE

I dont really get how thats a "trick".

Faerie

What annoys me is when the answer is colourless but they give you ZERO marks for saying clear.
Actually that's not as bad as when the answer is milky but you can't say creamy....:mad:

Feral Mutant

Faerie wrote:

Actually that's not as bad as when the answer is milky but you can't say creamy....:mad:

Yeah, for CO2's effect on limewater you can't say white or whitish. "Milky" is apparently the scientific term.

d4gurl

surely we know after two years to say colourless!

grimloch

Faerie wrote:

What annoys me is when the answer is colourless but they give you ZERO marks for saying clear.
Actually that's not as bad as when the answer is milky but you can't say creamy....:mad:

That's because colourless isn't the same thing as clear. Milky and creamy is what I have grievances with though.

Faerie

grimloch wrote:

That's because colourless isn't the same thing as clear.

Well it's a bit of a technicality! If you're trying to remember a colour change and you think back to when you did the experiment you might think clear. I mean I know not to say clear now, but it's still sort of irritating.
And surely creamy and milky is the same thing? I mean cream is just the rich part of the milk!!!

grimloch

Something could easily be blue and clear at the same time. Although it's certainly one of the easiest mistakes to make on the paper.

abercrombie

also with regard to potassium permanganate it's a vibrant purple colour..not deep purple as i learned in my mock...!

fatal

abercrombie wrote:

also with regard to potassium permanganate it's a vibrant purple colour..not deep purple as i learned in my mock...!

or else just say purple;)
also remember for the titrations that the ONLY two titrations where you have to find the conc before dilution are the ones with vinegar and bleach

abercrombie

fatal wrote:

or else just say purple;)
also remember for the titrations that the ONLY two titrations where you have to find the conc before dilution are the ones with vinegar and bleach

or was that deep purple and not vibrant...!

d4gurl

Deep Purple!! :d

happydance

Faerie wrote:

And surely creamy and milky is the same thing? I mean cream is just the rich part of the milk!!!

Apparently creamy is a texture (think ofthe galexy add) white milky is a colour or something!

abercrombie

d4gurl wrote:

Deep Purple!! :d

are you sure?!? i was going to settle for "intense purple"

d4gurl

nearly 100 percent!yeh it is