National 5 Chemistry 2018/19

Now that I think about it, I couldn't even find it on the SQA course specification page when I was browsing to ensure I had every point listed for what is contained within the examination on Friday.

Yeah they’ve taken everything out about cracking, fractional distillation and all of that. There might still be a question on it but they would provide all relevant info in the question - it would be a problem solving question.

Kind of like a blast furnace question then.

Yeah, exactly. Good idea to use the course specification - that’s literally every topic that could possibly come up 😊

Hi everyone! I was hoping for some help with one of the exam questions, it is Paper 2017, Section 2, Question 12)c). I always struggle with these questions and I’m stressing out because my exam is Friday and I don’t want to lose marks on something that everyone else seems to understand lol! Thanks in advance

Hi everyone! I was hoping for some help with one of the exam questions, it is Paper 2017, Section 2, Question 12)c). I always struggle with these questions and I’m stressing out because my exam is Friday and I don’t want to lose marks on something that everyone else seems to understand lol! Thanks in advance

What you want to do first is get the GFM/RFM (some schools call it different things) of both geraniol and geranyl propanoate which is just the relative atomic mass of the atoms in the compounds. Once you have the GFM/RFM you can use the equation to figure out the number of moles, which can then be used in the equation to find the mass of the propanoate

The equation is mass = moles * GFM.

This is how I was taught to do it, it might make no sense to you as there are many methods of doing questions like these. Hope it helps!

This is how I was taught to do it, it might make no sense to you as there are many methods of doing questions like these. Hope it helps!

Hi again, sorry to keep asking about this but how do you know it’s a 1:1 ratio? Lol, as you can probs tell I’m really bad at the maths/problem solving side of this course, God help me next in year in higher! 😂

If there's a big number in front of the compound then it's you know it's not a 1:1 eg if it's h20 and 2co2 then it's a 1:2 ratio

Bit of a weird question, but is there anyone else who actually likes taking exams? XD Don't ask me why; I just think it's competitive, which make it fun for me lol.

i get what u mean, and i feel like that for subjects that i’m good at, like chemistry, maths and drama, but see for subjects like english, history and physics, i dread the exams aha

So, whenever Chemistry exams come up, they always include weird questions that I have absolutely no idea how to answer. I was wondering if anyone had any ide how to answer this question? As I just have no idea what to do, despite knowing my notes:

Reference: National 5 Chemistry 2015 Section 2 Q4. (c)

And also, regarding radioisotopes; we never got a note on how having a different half life means something is better for a certain cause, (I asked my teacher; he said that they'll give you information on both, but looking at past papers, that's not the case) can anyone explain why? Because I assume there will be something like that in the exam

Calcium oxide is a metal oxide and sulphur dioxide is a non-metal oxide, you should know that a metal oxide, metal hydroxide and metal carbonates are all examples of bases and as it is reacting with a non-metal oxide, this causes a neutralisation reaction to occur as it is essentially an acid - alkali reaction. So to answer it, all you have to put down is : Calcium oxide is a base which reacts with sulfur dioxide, resulting in a neutralisation reaction taking place which will reduce the volume of sulfur dioxide released

And having a shorter half life is useful for radioistopes which involve the body as they dont stay in the body for long which would be harmful, longer half life is useful for radioisotopes in, for e.g, smoke detectors, as they then do not need to be replaced as often

Although I do have one question, how do you know which has a longer half-life? That wasn't in our notes.

You would either get told in the question if the radioisotope had a short/long half life and then to justify why, or they would ask you for a calculation to find the half life, dont think you need to know specifics for each radioisotope