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National 5 Chemistry

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Reply 320
Avatar for Jay431
Jay431
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Original post by Ethan100
Anyone know the answer to the last 2015 multiple choice question? How do you do it /

That a weird problem solving one.

I don't know if this is correct, But the answer would be yellows and here's why:

Copper sulfate - goes from Blue to green Copper Chloride.

How to you get the colour green? Mix blue and yellow together.

So the colour would be yellow.

You can check this with the other one.

Potassium chloride goes from colourless to YELLOW potassium chromate.

How to you get from colourless to yellow? Add yellow :P

I don't know the chemistry behind it but that's how I got the answer
Original post by Jay431
That a weird problem solving one.

I don't know if this is correct, But the answer would be yellows and here's why:

Copper sulfate - goes from Blue to green Copper Chloride.

How to you get the colour green? Mix blue and yellow together.

So the colour would be yellow.

You can check this with the other one.

Potassium chloride goes from colourless to YELLOW potassium chromate.

How to you get from colourless to yellow? Add yellow :P

I don't know the chemistry behind it but that's how I got the answer


Thanks Jay

Quick question, I was never taught what a precipitate reaction was, can you tell me ?

Good Luck for tomorrow
Reply 322
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Jay431
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Original post by Ethan100
Thanks Jay

Quick question, I was never taught what a precipitate reaction was, can you tell me ?

Good Luck for tomorrow


Basically it's when two soluble solutions react to form an insoluble substance, So the compound that becomes a solid in the reaction.

They can ask you this in two forms:

One way which is least common, is that they'll give you a formula equation and they'll ask you to identify the percipitate. The percipitate is the solid, the thing that's insoluble. So just look for the substance with an s next to it to indicate it's a solid. To check if you're right, go to the back of the data book and there's a page filled with the letters "i", "vs" and "s". Look up the compound that is the solid and check to see if there's an "i" next to it. If so then that's the percipitate.

The second way and most common way is that they'll say something like:
Identify the percipitate from the following reactions:
Ammonium Chloride and Silver Iodide

In this case what you want to do is the following:
Go to the back of the data book we're u see the soluble/insoluble compounds.
Instead of looking for "Ammonium Chloride" look for "Ammonium Iodide". If it's insoluble (it's got an i next to it) then it's the percipitate. If not then just try it with Silver Chloride NOT Silver Iodide.. And so on etc etc

To get practice at the second one ^^ look at Q19 2015
Original post by Jay431
Basically it's when two soluble solutions react to form an insoluble substance, So the compound that becomes a solid in the reaction.

They can ask you this in two forms:

One way which is least common, is that they'll give you a formula equation and they'll ask you to identify the percipitate. The percipitate is the solid, the thing that's insoluble. So just look for the substance with an s next to it to indicate it's a solid. To check if you're right, go to the back of the data book and there's a page filled with the letters "i", "vs" and "s". Look up the compound that is the solid and check to see if there's an "i" next to it. If so then that's the percipitate.

The second way and most common way is that they'll say something like:
Identify the percipitate from the following reactions:
Ammonium Chloride and Silver Iodide

In this case what you want to do is the following:
Go to the back of the data book we're u see the soluble/insoluble compounds.
Instead of looking for "Ammonium Chloride" look for "Ammonium Iodide". If it's insoluble (it's got an i next to it) then it's the percipitate. If not then just try it with Silver Chloride NOT Silver Iodide.. And so on etc etc

To get practice at the second one ^^ look at Q19 2015


Thanks so much :biggrin:
Can someone try and bring their copy of section 1 tomorrow when they are done with the exam ?
Original post by Ethan100
Can someone try and bring their copy of section 1 tomorrow when they are done with the exam ?


I'm not allowed too in my school unfortunately.
I will bring out a copy
Reply 327
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Jay431
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Original post by Ethan100
Can someone try and bring their copy of section 1 tomorrow when they are done with the exam ?


Good idea but my school will probably not let me

Original post by SocialStudiesETC
I will bring out a copy


Great we could get a marking scheme going then
Good luck today everyone!


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Good luck everyone! Just write your hearts out at the open-ended questions and lets hope we don't get any screwed up questions! You'll all be fine.
Reply 330
Avatar for Jay431
Jay431
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The 2014 and 2015 Chemistry course report comments on the difficulty of the last 2 papers in 2014 and 2015:

2014 - "The overall impression of the paper from feedback received was that the National 5Chemistry paper was fair but challenging."
2015 - "Feedback from markers and centres indicated that the overall impression of the question paper wasthat it was fair but challenging"


Could suggest they'll give us an easier paper this year maybe? :P

Either ways, good luck everyone!
(edited 7 years ago)
How did everyone find that? I found it okay, not too hard, but not very easy either haha
I put Salt bridge instead of ion bridge, will I still get the mark?:/
Reply 332
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Jay431
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Some questions were hard and some were not so hard.
Reply 333
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(bryn)
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i found that alright
i didn't like section 1 at all, but paper 2 was really easy imo
what did you guys put for the very last question? my friends keep talking about something to do with limewater being turned cloudy, but i wrote that you could test the pH to find out which is more acidic, which would tell you which one contained more, and i also wrote that they could perform a titration calculation, with the average amount needed to neutralise each time telling you which one had more

Original post by Marina1264
How did everyone find that? I found it okay, not too hard, but not very easy either haha
I put Salt bridge instead of ion bridge, will I still get the mark?:/


i've seen it labelled both ways in my notes
i debated between the two, and i think i chose ion bridge, but i think they refer to the same thing anyway
I thought it was okay! Made a few silly mistakes on relfection, but I thought it was generally good.
Did anyone say gold was a catalyst?


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First paper was weird and some questions in the second
Reply 337
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(bryn)
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Original post by Rebeccahughes15
Did anyone say gold was a catalyst?


yeah, i think it says in the passage that it's a catalyst
Original post by Rebeccahughes15
Did anyone say gold was a catalyst?


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I wasn't sure so i said reducing agent hahahaha
Did you get 17.3% for the composition one??


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