Take our quiz to find out what your revision personality is! >>

Higher Chemistry - Unit 1 NAB.

I've got my NAB tomorrow and I'm ******** it. I can't hardly do any of the molar volume thingys or enthalpy calcs. :indiff:

Don't even get me started on the PPAs... :sad:

Can anyone help me with the calculations (particularly excess/molar volume)? And, does anyone know how the NAB is structured? :s-smilie:

Another night of well deserved cramming heh :colonhash:

Realise i'm a day too late lol :P

I found my Unit1 chemistry NAB pretty easy tbh. Also, I didn't think PPA's were examined in NABs? So how did it go?

Reply 3

namedeprived

How did it go?

(Sorry, I would have tried to help had I seen this earlier.)

Reply 4

LuhLah

It was actually quite easy, but I've got some exam anxiety in that I've forgotten to write certain things etc...

The calcs kinda came naturally lol. I just hope I've passed!

Reply 5

jackwka

LuhLah

It was actually quite easy, but I've got some exam anxiety in that I've forgotten to write certain things etc...

The calcs kinda came naturally lol. I just hope I've passed!

What specific parts of enthalpy/excess etc were you stuck on?

Reply 6

LuhLah

jackwka

What specific parts of enthalpy/excess etc were you stuck on?

It was just calculating the enthalpy for the 1 mole of combustion of whatever, i just used the link, proportion and then cross multiply method :yep:

I figured out excess by simply finding the nms of both reactants, and the one with the higher value was in excess.

Starting to think I failed it now, but meh, I can always resit :awesome:

Reply 7

namedeprived

LuhLah

It was just calculating the enthalpy for the 1 mole of combustion of whatever, i just used the link, proportion and then cross multiply method :yep:

I figured out excess by simply finding the nms of both reactants, and the one with the higher value was in excess.

Starting to think I failed it now, but meh, I can always resit :awesome:

I'm sure you've probably passed anyway. :p:

In terms of excess thats's fine if it's a 1:1 ratio, but if for example you have the reaction

H_2O+ \frac{1}{2}O_2 -> H_2O

and you work out that you actually have 0.1 moles of oxygen and 0.15 moles of Hydrogen, then there is 0.025 moles excess oxygen

Reply 8

HD.x3

do you get asked about ppas in nabs?

Reply 9

GiantFrozenPenguin

So, why did you reply to this inactive thread instead of posting a new one? It's been 58,000,000 seconds since the last post. Oh and I believe you do get asked about PPAs in NABs

Reply 10

HD.x3

Original post by GiantFrozenPenguin

So, why did you reply to this inactive thread instead of posting a new one? It's been 58,000,000 seconds since the last post. Oh and I believe you do get asked about PPAs in NABs