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    (Original post by cupcakes16)
    Well thats stupid. I didn't get taught about different meanings of reduction :eek:
    Cgp book put reduction as oxygen loss quite clearly on one page and it as electron loss very obscurely a couple pages after, do you not revise from them ?
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    (Original post by lyricalvibe)
    BC AD I I think :/ I forgot the question :/ I seem to be the only one, but I'm thinking A couldn't have been a similarity as it was talking about oH and the word SEE was highlighted, I think B was hydrogen forming and that would be seen by bubbles I think as it was dilute solutions ( I really don't remember the question so this may be Be :s ) for c as a similar because they both made a white precipitate for the same reaction and D they one made a precipitate while the other didn't react, that was the hardest question on the paper because of the vagueness and how prone to error it is, I spent at least 5 mins on it and it's still the question I have doubts on in the paper :/

    what did you put and why?
    I put AB CD

    A was similar because they were both acidic and had low pH's.
    B was similar because they both produced hydrogen gas (I think I put hydrogen gas anyway..)
    C was dissimilar because it only made a precipitate with one of the acids and not the other, same goes for D.
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    (Original post by LouiseDB42)
    I'm fairly sure it's the gain of electrons, the question was about electrolysis and heating with carbon - to extract metals from their ores they must be reduced

    Posted from TSR Mobile
    Reduction as electron exchange isn't part of the spec while reduction as oxygen exchange is. Also, the fact it was talking about heating with carbon is further supportive of oxygen exchange as carbon get's oxidized normally in reduction, I think though because the question was stand alone I believe and vague(reduction ghas 4 scientific definitions I believe) and OCR can't really penalise you for knowing too much electron loss will be accepted for at least 1 mark
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    (Original post by lyricalvibe)
    It's not you it's me...
    A- I don't think it could be part of the similar category as I think the similarities had to be seeable and pH Isn't visible; you need to test pH. So I said diff as they will likely have diff pH on a pH meter which is really accurate- this point believe is wrong because why the shell can't they have the same pH?
    B- I'm if the question said stuff about dilute or dissolved I believe this could be a valid similarity as hydrogen bibles will be produced (I only said hydrogen gas and that's cloudless so once again my justification is whack)
    C- only answer I'm certain about and it is a similarity as it produces a white precipitate on both reactions- correct me if I'm wrong
    D- when I looked up the reaction on the front page I didn't see chloride ion s to produce any precipitate this way so I don't understand people's justification of this being a similarity but I'm sure someone could tell me...(ps. I said it was a difference because f this as one would react to produce a precipitate and one wouldn't-something along them lines)


    What did you put? If someone can justify D as similar then I'm thinking that's the answer: CD AB
    A and B different:

    A - exact same reasons (different acidity so different pHs)
    B - HCl would react faster than H2SO4


    C and D similar:
    C and D - same reasons given as 'both form a white precipitate'
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    Phew, I'm not the only one who messed up on that ABCD question that question was so ambiguous and was really annoying. Well nothing we can do now. How does everyone feel for physics?


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    (Original post by Sulfur)
    A and B different:

    A - exact same reasons (different acidity so different pHs)
    B - HCl would react faster than H2SO4


    C and D similar:
    C and D - same reasons given as 'both form a white precipitate'
    What was the reagent for D because I didn't think one of them formed a white precipitate and I can check now from a past paper,it was barium chloride wasn't it? Barium chloride (the reagent) and hydrochloric acid don't form a white precipitate I don't think.. :confused:

    Apart from that your points seem solid C seems a deff inate similarity so that's 2 marks I'm guessing if their was a good reason?
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    (Original post by Sulfur)
    A and B different:

    A - exact same reasons (different acidity so different pHs)
    B - HCl would react faster than H2SO4


    C and D similar:
    C and D - same reasons given as 'both form a white precipitate'
    I had the pairs the other way around because it said which tests produce the SAME RESULT for BOTH acids: test C produced a white precipitate in HCl but nothing in H2SO4 whereas test D produced nothing in HCl but a white precipitate in H2SO4, therefore the results of those two tests are different for each acid. Tests A and B were similar because their phs would both show they were acidic, and they would both react with magnesium in the same way (salt + hydrogen with fizzing)

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    (Original post by cupcakes16)
    Yes thats exactly what i put. Is it right?
    Yeah I put something similar too is it me or for this paper was there not enough space to write answers? I used 2 pages of an additional answer booklet :/ but I have large handwriting anyway
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    (Original post by lyricalvibe)
    What was the reagent for D because I didn't think one of them formed a white precipitate and I can check now from a past paper,it was barium chloride wasn't it? Barium chloride (the reagent) and hydrochloric acid don't form a white precipitate I don't think.. :confused:

    Apart from that your points seem solid C seems a deff inate similarity so that's 2 marks I'm guessing if their was a good reason?
    Silver nitrate and barium chloride I think.
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    (Original post by LouiseDB42)
    I had the pairs the other way around because it said which tests produce the SAME RESULT for BOTH acids: test C produced a white precipitate in HCl but nothing in H2SO4 whereas test D produced nothing in HCl but a white precipitate in H2SO4, therefore the results of those two tests are different for each acid. Tests A and B were similar because their phs would both show they were acidic, and they would both react with magnesium in the same way (salt + hydrogen with fizzing)

    Posted from TSR Mobile
    I see your point, but pH metres show a specific pH to about three d.ps hence they'd vary. Similarly they'd react at different rates - all showing something different. Then again, you could say that they both show hydrogen gas.
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    (Original post by olmyster911)
    I put AB CD

    A was similar because they were both acidic and had low pH's.
    B was similar because they both produced hydrogen gas (I think I put hydrogen gas anyway..)
    C was dissimilar because it only made a precipitate with one of the acids and not the other, same goes for D.
    Duck(f). I was kinda maybe sorta hoping to get 50+ and you've ruined that -_- I now believe C is wrong as their is no way they both produce white precipitate
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    (Original post by Sulfur)
    Silver nitrate and barium chloride I think.
    I seemed to take barium nitrate and silver nitrate as the same thing in the exam
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    I'm just thinking - these ABCD questions were separated into three marks each, totalling six marks. Do you think that you could get I don't know, C and D wrong but A and B right but for different reasons since the marks have been separated for the full question?

    For example:

    A and B are similar: A shows different pHs, B shows different rates
    C and D aren't similar: Both produce white precipitates

    Despite C and D being wrong I think, don't you think they could give you 3/6 for A and B being right?
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    (Original post by lyricalvibe)
    Duck(f). I was kinda maybe sorta hoping to get 50+ and you've ruined that -_- I now believe C is wrong as their is no way they both produce white precipitate
    I aim to please

    That's just my way of looking at it, but I know there are tonnes of different theories circulating on this thread. Plus, 50+ is a grand target to set
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    (Original post by Sulfur)
    I'm just thinking - these ABCD questions were separated into three marks each, totalling six marks. Do you think that you could get I don't know, C and D wrong but A and B right but for different reasons since the marks have been separated for the full question?

    For example:

    A and B are similar: A shows different pHs, B shows different rates
    C and D aren't similar: Both produce white precipitates

    Despite C and D being wrong I think, don't you think they could give you 3/6 for A and B being right?
    I think because it was a 6 marker in total, they'd be allot of exceptions like "award mark if incorrect answer but valid justification" kinda like error varied forward
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    (Original post by lyricalvibe)
    I think because it was a 6 marker in total, they'd be allot of exceptions like "award mark if incorrect answer but valid justification" kinda like error varied forward
    Yes, exactly. Maybe there is hope now!
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    (Original post by olmyster911)
    I aim to please

    That's just my way of looking at it, but I know there are tonnes of different theories circulating on this thread. Plus, 50+ is a grand target to set
    Haha :lol:

    Your way seems right it went better than my mock in terms of how I felt after and I got in the 50s for that plus my teacher doesn't really like me for chem so it's kind of to prove to her something, I also am starting to like chemistry and it's probs my favourite science-if those even exist
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    How's everyone feeling for physics?
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    (Original post by lyricalvibe)
    How's everyone feeling for physics?
    Much easier content is less and literally follows on from p123 and c456 kinda
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    (Original post by Swag>education)
    Much easier content is less and literally follows on from p123 and c456 kinda
    For p4 and 6 I agree but I gotta do some work on 5, I actually hate circuits! You wired for maths then?
 
 
 

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