Equilibria, Energetics and Elements (F325) - June 2011 Exam.

gold lock question:::

is the number of mols of carbon in CaC2 the same as the number of moles in 3C if the equation is :

CaO + 3C ----> CaC2 +CO

and n of Ca 1:1 ??

to find overall n of CaC2 can i add the number of mols together ?

Reply 1483

Original post by maniRB

FML! Thanks :smile:

you're tired and probs made lots of careless mistakes!!!

Reply 1484

Original post by goldlock

I'd begin by writing down all of the reactants/products that you're given in the question, aside from any hydroxide ions, protons or H20 that you may well need to even things up - so, begin with saying that N02 + I- goes to I2 + NO
Then, you need to work out which of these atoms change oxidation number, and balance those atmos that do (so, I goes from -1 to 0 so balance the number of iodines). That should set you on your way :smile:

hi again, how did u know that NO was going to be a product?

Reply 1485

http://www.youtube.com/watch?v=6QzPxLeJhjw&feature=related

to cheer people up :biggrin:

its gnna be a long night!

Reply 1486

Original post by hey-hey-hey

hi again, how did u know that NO was going to be a product?

They asked you that in the part just before this one, a colourless gas is produced with molar mass of 30 :smile:

Reply 1487

Original post by bambinooo

gold lock question:::

is the number of mols of carbon in CaC2 the same as the number of moles in 3C if the equation is :

CaO + 3C ----> CaC2 +CO

and n of Ca 1:1 ??

to find overall n of CaC2 can i add the number of mols together ?

please someone answer this question :frown:

Reply 1488

Original post by bambinooo

gold lock question:::

is the number of mols of carbon in CaC2 the same as the number of moles in 3C if the equation is :

CaO + 3C ----> CaC2 +CO

and n of Ca 1:1 ??

to find overall n of CaC2 can i add the number of mols together ?

Sorry, I don't quite understand what you're asking :frown:

is this even on the spec?

Reply 1489

hiyarearl

4

Off to bed now, will do a past paper tomorrow morning then hope for the best.

Good luck everyone! :biggrin:

Reply 1490

Original post by bambinooo

http://www.youtube.com/watch?v=6QzPxLeJhjw&feature=related

to cheer people up :biggrin:

its gnna be a long night!

who is that? is that you?
its rly good

Reply 1491

Original post by goldlock

Sorry, I don't quite understand what you're asking :frown:

is this even on the spec?

i have no idea but i dont trust ocr so i'm covering all my bases ....in the specimen paper question 6 d) there was a question that asked us to do something similar to the question i asked in terms of using the mass of products to work out moles of elements in the product...! maybs im over thinking it .... :frown:

thanks anyway :P

Reply 1492

Original post by hey-hey-hey

who is that? is that you?
its rly good

hahah no i wish... watch this : his name's jake shimba something i think that was a cover though of jakes stuff...

http://www.youtube.com/watch?v=VyQXNf6OAKM&feature=related

Reply 1493

ruby321

11

I'm so nervous about tomorrow... half of the questions on the Jan 2011 paper were impossible to me and I havn't done any of the examination questions in the textbook and so that makes me feel uneasy.. I'm so scared :frown:

Good luck everyone and just to confirm, it is at 1.30pm tomorrow right?

Reply 1494

susan23

3

hello late nighters :biggrin:

Reply 1495

Original post by goldlock

They asked you that in the part just before this one, a colourless gas is produced with molar mass of 30 :smile:

ohh yeah ooooppsss!! :/ im tired
thank you
you're reeally helpful
Thanks a bunch :smile:

Reply 1496

Original post by bambinooo

i have no idea but i dont trust ocr so i'm covering all my bases ....in the specimen paper question 6 d) there was a question that asked us to do something similar to the question i asked in terms of using the mass of products to work out moles of elements in the product...! maybs im over thinking it .... :frown:

thanks anyway :P

Oh right - yeah I don't trust 'em either, these bastards hold our chemistry grade in our hands eh :P
but I can show how to do that question off the specimen paper if you want

Reply 1497

Original post by bambinooo

hahah no i wish... watch this : his name's jake shimba something i think that was a cover though of jakes stuff...

http://www.youtube.com/watch?v=VyQXNf6OAKM&feature=related

Ahh thats good too,
ahh im jealous i wish i could play that instrument, Ukalali? something aha i cant spell :/

Reply 1498

Original post by hey-hey-hey

ohh yeah ooooppsss!! :/ im tired
thank you
you're reeally helpful
Thanks a bunch :smile:

happy to help :smile:

Reply 1499