i suck at chem, help! (1 Viewer)

[foxdog88]

hi,
i am in year 11 and i really like the subjetc but i'm really struggling with managing the work load and sporting commitments as i have fallen a bit behind in the work after the moles topic which i made almost no sense of.

Please if anyone has any advice, notes or ways to help i would be very greatful for it.

Thanks heaps

 

[jumb]

The moles topic is pretty hard. IIRC, the only things you need from that topic was the formulas (n = m/M etc.). If you're enjoying the course then stress less.

 

[Casmira]

I had the same troubles, I fell back due to workign 6 days a week (not a good idea in year 11 ), so I spent 1-1.5hrs a day from the chemical earth and metals working through 'preliminery conquering chemistry' - i did every single question, summarised everything, and understood moles very well, 2 months later when the yearly for chemistry came, I had studied all the 4 topics, just as indepth, when I got the test back, I had got 14/15, 15/15 for metal and chemical earth (the test was split up in perfect 4 sections of 15 marks in each topic), the other 2 sections (energy and water) i got like 6-8, not too good

its a good idea to try and nail in the course, you might think you'll forget, and you probably will, but when you try and reintroduce a concept, you're most likely to remember that, I admit I forgot half of what I studied when the half yearly came 2 months later, but damn when I studied over things they came back to me

 

[Emma-Jayde]

Is there any part of the topic in particular you're having trouble with, or just the whole lot? If you have specific questions, or examples of questions you don't understand, post them here and we can help you work through them. But like jumb said, you need to know the formulas, n=cv, n=m/M etc.

 

[Jumbo Cactuar]

Is there any part of the topic in particular you're having trouble with, or just the whole lot? If you have specific questions, or examples of questions you don't understand, post them here and we can help you work through them. But like jumb said, you need to know the formulas, n=cv, n=m/M etc.

It is all very intuitive. You can't go wrong if you do a seperate 'units' equation.

 

[Emma-Jayde]

You can't go wrong if you do a seperate 'units' equation.

...I know some people who can...Don't ask me how, I haven't figured that one out yet

 

[DraconisV]

The moles topic is pretty hard. IIRC, the only things you need from that topic was the formulas (n = m/M etc.). If you're enjoying the course then stress less.

huh formulas, what formulas ive started the mole topic and im up to molarity and that molarity concentration formula and that other one moles over mass equals mols/g whats these other n= cv, n= m/M. can someone give me the low down on all these formulas for the mole topic coz my teacher said to me that i had done all these hard insane q's without all these formulas and he was amazed at how i bloody got the right answer, lol

also for us prelims out there wat section are you up to at the moment, im up to moles but we have also done alot on hydrocarbons and energy so that topic we will breeze through.

thx guys

 

[Dreamerish*~]

yeah moles took awhile.

i already learnt them in year 9, so it wasn't as hard for me to understand.

i think it's important to be interested in chemistry for you to do well. when you're interested it's easier to understand the concepts behind it. if you're forcing yourself to do chem, you'll struggle a lot more.

 

[Jumbo Cactuar]

mol = weight of sample (g) / molar weight (g/mol)

Nice try, though you should say;

Amount of substance (n, mol) = mass of sample (m, g) / molar mass (M, g/mol)

Since moles is the SI unit of amount of substance and weight is the force applied to a mass by a 'gravitational field'.

 

[nit]

yep, dimensional analysis is a good skill to have in any subject, especially phys and chem.

 

[Jumbo Cactuar]

Oh and this one is obvious, but is worth a post. Molar is another unit for concentration which is equivelent to moles/litre.

So 15M HCl is '15 molar HCl'
which is the same as
15 mol.L^-1 HCl


It is analogous of;
hertz or per seconds.
pascals or newtons per metre squared.
siemens or per ohms.