Chemistry 3/4 2013 Thread

[thushan]

H₂SO₄ (l) is concentrated Sulfuric Acid. H₂SO₄ (aq) is not.

The more concentrated the sulfuric acid is, the greater the rate of reaction, therefore the faster the esterification. This is because there will be a greater amount of molecules present in the reaction mixture, leading to a greater number of collisions occurring between reactant molecules at a particular time frame.

(Mainly concerns Collision Theory, explored in U4)

Actually, no. It's an equilibrium consideration rather than a reaction kinetics really. It's mainly that esterification is reversible (the reaction occurs both ways), and water is a product of that reaction. Since H2SO4(l) has a shitload of water floating round, most of the ester formed will be hydrolysed. If it were H2SO4(l), the only water would be from the condensation reaction, so most of the ester formed will stay as the ester.

[curry_bro]

is it a problem that i can barely do half the questions here at the moment??? i really want a 45! :S ive barely done many year 12 questions! am i stuffed??

[Homer]

I want a 45 too

[thushan]

is it a problem that i can barely do half the questions here at the moment??? i really want a 45! :S ive barely done many year 12 questions! am i stuffed??

Not @ all. Dude, you barely started learning the course. It takes time.

When I was studying bio in the holidays, I could barely get half the questions myself.
When I was studying English Language, I could barely do a single exam question until well into the year. When I got my first essay at 11.5/15, I was quite upset, thinking I will never be able to scale 40 in the subject. I just kept writing essays, and slowly I improved. You don't notice your improvement at all until when you get to the exam.

[Mr Keshy]

Not @ all. Dude, you barely started learning the course. It takes time.

When I was studying bio in the holidays, I could barely get half the questions myself.
When I was studying English Language, I could barely do a single exam question until well into the year. When I got my first essay at 11.5/15, I was quite upset, thinking I will never be able to scale 40 in the subject. I just kept writing essays, and slowly I improved. You don't notice your improvement at all until when you get to the exam.

This gives me hope

Chem is awesome though, so I'll go the extra length to understand it even further.

[teletubbies_95]

I'm hoping for a 35+ for chem . It's going to be hard.....
And curry bro.. You so smart, why are you worrying??

[Jeggz]

Not @ all. Dude, you barely started learning the course. It takes time.

When I was studying bio in the holidays, I could barely get half the questions myself.
When I was studying English Language, I could barely do a single exam question until well into the year. When I got my first essay at 11.5/15, I was quite upset, thinking I will never be able to scale 40 in the subject. I just kept writing essays, and slowly I improved. You don't notice your improvement at all until when you get to the exam.

thushan,
how would you say the best way to study chem is?
review it every night after class, and do a certain number of questions?
or making summaries..? any advice?

[Homer]

also would working together help?

[Mr Keshy]

thushan,
how would you say the best way to study chem is?
review it every night after class, and do a certain number of questions?
or making summaries..? any advice?

I was advised to do both. Make summaries of each of the chapters after they're completed.

[teletubbies_95]

Do as many questions as you can...

[curry_bro]

I'm hoping for a 35+ for chem . It's going to be hard.....
And curry bro.. You so smart, why are you worrying??

i dont know :S i fluked bio... if anyone saw my sig before the 17th, i was aiming for a 37 in bio, and somehow shot past my (and my school's) expectation. im not very naturally gifted at science. im more of an english/health kinda kid, who got lucky come the unit 4 biology exam haha! and by the way youre answering questions, i wouldnt be surprised if u push past a 43 raw have some faith! we all know curries are brilliant, now all you need to do is make that reality eventuate in the form of your chem ss

Not @ all. Dude, you barely started learning the course. It takes time.

When I was studying bio in the holidays, I could barely get half the questions myself.
When I was studying English Language, I could barely do a single exam question until well into the year. When I got my first essay at 11.5/15, I was quite upset, thinking I will never be able to scale 40 in the subject. I just kept writing essays, and slowly I improved. You don't notice your improvement at all until when you get to the exam.

coming from the academic prodigy, this is quite comforting. i have to study my fricken ass off this year :/

[teletubbies_95]

Dude. Don't say anything. Your smart. Period.
I just like answering questions. And no, I'm aiming 35+ , I'm not tht smart.

Post more questions up guys !!! And answer my questions !!

[thushan]

thushan,
how would you say the best way to study chem is?
review it every night after class, and do a certain number of questions?
or making summaries..? any advice?

Questions, questions, questions.

[Homer]

I keep getting ~0.00494mols :/

[Milkshake]

I keep getting ~0.00494mols :/

so the reaction happening is:
HCl(aq) + excess NaOH(aq) = NaCl(aq) + H20(l)
since were given the titre of HCl and its concentration, we can find n(HCl)
n(HCl) = 0.298 x 0.01864 = 0.00555472
n(HCl) and n(NaOH) are in a 1:1 ratio, so n(NaOH excess) = 0.00555472