SQA National 5 Chemistry -1st May 2025 [Exam Chat]

Does anyone know what they got on the MC question that said something like:
"what is the GFM of a hydrocarbon not in the same homologous series".
It would be very helpful if you could just say how you got to the answer.
Thanks

Hi! I think I could help.
Firstly, you think about the molecular formula of the common hydrocarbons.
(Alkanes) - CnH2n+2 (general formula)
methane CH4
= 16
propane C3H8
= 44
butane C4H10
= 58
pentene C5H10 ( alkene )
= 70
so the answers is D, because it’s an alkene not an alkane. I hope this help you figure out the way to the answer, so yeah just keep in mind of the general formulas. And it usually goes in a pattern so keep an eye out when it says does not belong in the same homologous series!

Thank you very much!
It makes so much sense now.

Does anyone know what they got on the MC question that said something like:
"what is the GFM of a hydrocarbon not in the same homologous series".
It would be very helpful if you could just say how you got to the answer.
Thanks

I don't remember exactly but I think I got 0.152?

btw guys, there's this teacher on yt that's going over the solutions @DocHillStudy 💪

Am I got like 1 or 2 out of 7 for Q1, do you know if they would accept 86 for the calculation question?

it would be quite harsh if they didn't accept it because the graph was small n a bit hard to read.

Ye, the paper this year was apparently more difficult than recent years so the mark scheme might be more lenient, anyway the rest of my answers were quite good. Apart from the balance equation question, who ever said you need to use fractions?

I also got 0.152, was that correct? Also could anyone balance the equation? Because everyone I spoke to had no idea how to do it.

Im so disappointed in myself for that question, I remember getting 0.152 for the concentration but I had no idea why I divided that ?? Like I just double the last part like when u divide the volume, i did that TWICE? idek why but I swear I was looking at it like it was wrong. Also the balancing equations was so hard i swear I ended up writing 4.5 bc I saw it on a past paper

yeahh i put that down too but honestly i had no idea

I wrote measuring cylinder will I still get the mark

I wrote measuring cylinder will I still get the mark

I had no idea you could use decimals, none of my teachers ever said I could do that

Ye, the paper this year was apparently more difficult than recent years so the mark scheme might be more lenient, anyway the rest of my answers were quite good. Apart from the balance equation question, who ever said you need to use fractions?

in my opinion, the paper this year was simpler than previous years. Lots of people on tiktok finding the exam easy