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Chemistry build up and aftermath

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  • Registered Users Posts: 18,159 ✭✭✭✭phasers


    Anybody home yet? I think I may have actually passed! (I dropped down :pac: ) and I managed to answer 8 questions properly. I think I at least passed/sneakily hoping for some sort of C


  • Closed Accounts Posts: 127 ✭✭mikeglee


    Having done the exam...I have a new found hate for the subject of that which is chemistry.


  • Registered Users Posts: 789 ✭✭✭jen_23


    How did ye get on guys. What came up for ye expected unexpected?


  • Moderators, Music Moderators Posts: 8,490 Mod ✭✭✭✭Fluorescence


    I have no idea how it went.... I thought I'd passed the mock and failed, and thought I'd failed the winter exam but passed.... I answered 8 questions anyway, and at least 3 or 4 of them are kinda waffley.... :o


  • Registered Users Posts: 1,082 ✭✭✭Fringe


    Went very well :D

    Q3 looked very intimidating at the start but was actually pretty easy. Also, bleach didn't come up. Thought experiments was going to be a disaster but they were so easy.


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  • Closed Accounts Posts: 407 ✭✭OxfordComma


    Happy overall, I think I got my A1 :D

    Anyone else do Q.3? That was the most EPIC tests for anions question ever! :D

    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?


  • Registered Users Posts: 313 ✭✭HQvhs


    1fahy4 wrote: »
    Happy overall, I think I got my A1 :D

    Anyone else do Q.3? That was the most EPIC tests for anions question ever! :D

    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?
    Yep, yep and yep! Great paper, experiments were a surprise (except ethyne & ethene) but loved them!


  • Closed Accounts Posts: 67 ✭✭Dmullar


    Went really well!

    Like physics, the experiments were really doable.

    Answered all the questions, hoping for an A:D


  • Closed Accounts Posts: 55 ✭✭Waaahhh


    1fahy4 wrote: »


    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?

    Yep!! Was looking for a trick in that question but couldn't find any!

    That couldn't have gone any better...

    And now I'm finished :D:D
    The mention of whiskey in question 8 had me thinking about the next few days...


  • Registered Users Posts: 168 ✭✭RayCarley


    What a nice paper. So many of the prediced parts actually came up! Like pretty much all of that paper was predicted in some shape or form.

    So yeah hopefully got the old A...

    Only 3 left, woooo :o


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  • Registered Users Posts: 1,257 ✭✭✭JSK 252


    Waaahhh wrote: »
    Yep!! Ws looking for a trick in that question but couldn't find any!

    That couldn't have gone any better...

    And now I'm finished :D:D
    The mention of whiskey in question 8 had me thinking about the next few days...

    The trick is the dilution factor if there is any such thing as a trick! lol

    Whiskey lol. What other ****ing substance is there in whiskey except just pure auld ethanol!

    Flavouring agent? I mean I have heard the word condiment being used for vinegar being put on chips but wtf? lol Vinegar is nice though.

    Lovely the way it led you to getting the 6% w/v.

    Did q1,2,3 ( lovely the way you could just tick the salts off ), 4,6,7,8,10 (a) and (c)


  • Closed Accounts Posts: 78 ✭✭arthistory


    1fahy4 wrote: »
    Happy overall, I think I got my A1 :D

    Anyone else do Q.3? That was the most EPIC tests for anions question ever! :D

    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?


    Yep i got 510 ppm too!!:D

    What did you say for problems if water supply pH was out of range from 6-8? I said corrosion of pipes if too low and hard water if too high.

    also is nitrates and phosphates the nutrients....and secondary treatment???


  • Registered Users Posts: 5,533 ✭✭✭Zonda999


    That went great. Couldn't have been happier with that really

    Q3 was great if you knew it


  • Closed Accounts Posts: 5,109 ✭✭✭QueenOfLeon


    1fahy4 wrote: »
    Happy overall, I think I got my A1 :D

    Anyone else do Q.3? That was the most EPIC tests for anions question ever! :D

    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?

    Yup!! :D
    JSK 252 wrote: »
    Did q1,2,3 ( lovely the way you could just tick the salts off ), 4,6,7,8,10 (a) and (c)

    I did the exact same qs as you, with q5 as an extra question....i thought it was really nice, the experiments were lovely! :D


  • Closed Accounts Posts: 287 ✭✭Des23


    1fahy4 wrote: »
    Also, did anyone else get 510 ppm for the B.O.D of the brewery effluent?

    I'm open to correction, but it said they had 5 litres then they used half of it for the first one, which means that the two BOD readings given were for 2.5 litres. So would you not say that 5.1 ppm was used by 2.5 litres then work out for 1 litre then multiply the dilution factor?

    I got 204 or 205 for what its worth...


  • Registered Users Posts: 131 ✭✭Nihilist21


    Very happy with how that went! Did an extra question, which is the first time I think I've ever done that for a Chemistry exam. Hopefully I got my A1 for that, there was only a couple of things I wasn't too sure of which I may check up now - overall it was a sexy paper though. And also, yay Leaving Cert finished!


  • Closed Accounts Posts: 407 ✭✭OxfordComma


    Oh yeah, anyone else not do Q.1?? That was a first for me... I completely blanked for part (b)...:eek:

    Anyone else get delta H= -10 for the heat of formation?


  • Closed Accounts Posts: 609 ✭✭✭GA361


    JSK 252 wrote: »
    The trick is the dilution factor if there is any such thing as a trick! lol

    Whiskey lol. What other ****ing substance is there in whiskey except just pure auld ethanol!

    Flavouring agent? I mean I have heard the word condiment being used for vinegar being put on chips but wtf? lol Vinegar is nice though.

    Lovely the way it led you to getting the 6% w/v.

    Did q1,2,3 ( lovely the way you could just tick the salts off ), 4,6,7,8,10 (a) and (c)

    For 10 c (iii),did you get 20.19?


  • Closed Accounts Posts: 6 monkseyz


    i think it was a nice enough paper, got confused witht he anion tests though lol but think i got them right (hopefully)
    wat's a use of ethanoic acid the 1 molar quantity one? was it vinegar?


  • Closed Accounts Posts: 609 ✭✭✭GA361


    1fahy4 wrote: »
    Oh yeah, anyone else not do Q.1?? That was a first for me... I completely blanked for part (b)...:eek:

    Anyone else get delta H= -10 for the heat of formation?

    Yeah . . . . I thought i was wrong cos the figure was so low . . . . but it seems it must be right:D


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  • Closed Accounts Posts: 5,109 ✭✭✭QueenOfLeon


    1fahy4 wrote: »
    Oh yeah, anyone else not do Q.1?? That was a first for me... I completely blanked for part (b)...:eek:

    Anyone else get delta H= -10 for the heat of formation?
    GA361 wrote: »
    For 10 c (iii),did you get 20.19?

    I got the same as both of those....hope we're all right! :D


  • Registered Users Posts: 131 ✭✭Nihilist21


    1fahy4 wrote: »
    Anyone else get delta H= -10 for the heat of formation?

    That's what I got.


  • Moderators, Music Moderators Posts: 8,490 Mod ✭✭✭✭Fluorescence


    Yep vinegar :P

    Argh I hate the anion tests! Everyone seems to love em but they all just become one big fuzzy blur to me :P

    I did Qs: 1,2,3,4,5,8,9,10b and c, 11 a and b.. but 11 won't count cause it's just pure crap :o


  • Registered Users Posts: 221 ✭✭smndly


    Right-o, heres a couple of my answers for comparison:

    Q.1 e (iii) 32.3% iron in the tablets

    Q4 f - pH of nitric acid = 1.6

    Q6 e - Heat of formation of C4H8 = -10 kj/mol^-1 ??? Bit weird i thought...

    Q8 d - 6% (w/v)

    Q10 (a) moles of chlorine = 1.5 moles

    (c) Relative Mr of neon = 20.19

    Q11 a v catalyst does not effect the value of Kc... not sure if that right though!
    :pac::pac::pac::pac:


  • Closed Accounts Posts: 609 ✭✭✭GA361


    Des23 wrote: »
    I'm open to correction, but it said they had 5 litres then they used half of it for the first one, which means that the two BOD readings given were for 2.5 litres. So would you not say that 5.1 ppm was used by 2.5 litres then work out for 1 litre then multiply the dilution factor?

    I got 204 or 205 for what its worth...

    But the dilution factor of 100 remains the same. . . . as there is only 25cm in that 2.5L sample


  • Closed Accounts Posts: 407 ✭✭OxfordComma


    Des23 wrote: »
    I'm open to correction, but it said they had 5 litres then they used half of it for the first one, which means that the two BOD readings given were for 2.5 litres. So would you not say that 5.1 ppm was used by 2.5 litres then work out for 1 litre then multiply the dilution factor?

    I got 204 or 205 for what its worth...


    That kinda makes sense but it's not the way they do it in the book... Ah well, if I did it wrong I only lost 3 marks anyways! I really don't care all that much at this stage:D


  • Closed Accounts Posts: 287 ✭✭Des23


    did everyone remeber to change the sign of the heat of formation at then end as you had to reverse the heat of formation of C4H8 for everything to cancel?

    It was 10 or -10 I can't remember..


  • Closed Accounts Posts: 55 ✭✭Waaahhh


    GA361 wrote: »
    But the dilution factor of 100 remains the same. . . . as there is only 25cm in that 2.5L sample

    +1

    (I hope so anyway)


  • Closed Accounts Posts: 407 ✭✭OxfordComma


    smndly wrote: »
    Right-o, heres a couple of my answers for comparison:

    Q.1 e (iii) 32.3% iron in the tablets

    Q4 f - pH of nitric acid = 1.6

    Q6 e - Heat of formation of C4H8 = -10 kj/mol^-1 ??? Bit weird i thought...

    Q8 d - 6% (w/v)

    Q10 (a) moles of chlorine = 1.5 moles

    (c) Relative Mr of neon = 20.19

    Q11 a v catalyst does not effect the value of Kc... not sure if that right though!
    :pac::pac::pac::pac:


    I think I got all of those!! Left out the ****ing units for delta H though:eek:... There goes a few marks...:(


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  • Closed Accounts Posts: 154 ✭✭eoins2345


    Just wondering did ye get 32.03% for the the percentage by mass of iron in the tablets?
    -10 for the heat of formation ting?
    BOD of 510?
    In q10a did ye get 3 moles and in 10c 2.19?


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