Required practical 2: Measurement of an enthalpy change

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  • Опубліковано 23 лют 2018

КОМЕНТАРІ • 50

  • @tommahon8779
    @tommahon8779 6 років тому +59

    i am so glad there's videos like this on the internet XD

  • @farhaanhasan
    @farhaanhasan 5 років тому +85

    the reaction is exothermic therefore the overall enthalpy change is negative -41.02. H1 should be -36.95 as it is an exothermic reaction as the temperature rose by 9. H2 is an endothermic reaction therefore should be +4.02.

    • @pardhivkondreddy6848
      @pardhivkondreddy6848 2 роки тому +3

      Yes, I had the same doubt. Q = mcΔT however Q here is energy. Not ENTHALPY CHANGE. The equation for enthalpy change must be:
      ΔH=-mcΔT
      Hence ΔH3 in the experiment conducted would be -41.0 J per mole and not 41 J per mole.
      Correct me if I am wrong.

    • @davankk2857
      @davankk2857 2 роки тому

      @@pardhivkondreddy6848 wouldn't the equation for enthalpy change be (delta)H = -mc(delta)T/n ?

    • @maxmarshall484
      @maxmarshall484 2 роки тому +2

      @@davankk2857 yes, if temp increases q=negative, if temp decreases q=positive, hence q is in J convert to KJ then Kj/Mol = enthalpy change

    • @rhysstevomusic1338
      @rhysstevomusic1338 2 роки тому

      It's because it's supposed to be -q/n

    • @rhysstevomusic1338
      @rhysstevomusic1338 2 роки тому +2

      Also delta H1 has been added up wrong, should be -37.62. Also, Delta H2 should be 4.01.

  • @jamesmcmillan2741
    @jamesmcmillan2741 3 роки тому +3

    Many thanks Tabitha you're magic!

  • @cherrycolagames3187
    @cherrycolagames3187 3 роки тому +21

    I’m doing this practical next week, thank you for this video :-)

    • @Xxxkska
      @Xxxkska 8 місяців тому +1

      What grade did you get

    • @shourya9649
      @shourya9649 3 місяці тому

      wat grade did u get for ur final exam

  • @revision4890
    @revision4890 6 років тому +3

    This is fantastic!

  • @danielahmed2051
    @danielahmed2051 5 років тому +6

    Can you please make videos on the other practicals as well as the a level ones

  • @Jess-bn8gm
    @Jess-bn8gm 3 роки тому +3

    Love this. Thanks xx

  • @mohamedhashi9276
    @mohamedhashi9276 2 роки тому

    Great vid ! 👍🏾

  • @A--Hollow
    @A--Hollow Рік тому +1

    Thanks!

  • @choosingmusic11488p
    @choosingmusic11488p 5 місяців тому

    helped for my gcse next week

  • @xenne.
    @xenne. Рік тому +2

    day before paper one

  • @liyanacapper8043
    @liyanacapper8043 4 місяці тому +1

    why are the arrows pointing down, i thought that was only used for combustion values?

  • @hoonlvr7213
    @hoonlvr7213 3 роки тому +1

    THANK YOUUU

  • @administracaogestao2664
    @administracaogestao2664 Рік тому +1

    Thank you

  • @MK-sh7ol
    @MK-sh7ol Рік тому

    Hi, thank you for this video, it was really helpful. Can you please explain why after finding the temp change in Celsius you didn’t add 273 to convert it into kelvin? Because you changed the sign from c to k but the numbers remained the same.

    • @bloothechronosapien4288
      @bloothechronosapien4288 Рік тому +3

      Change in temperature is used in the equation so the difference in kelvin is same as difference in Celsius. Say temp changed from 20 to 25 C, 25 - 20 is same as (25+273) - (20+273)

  • @RosyMSPAngel
    @RosyMSPAngel 2 роки тому

    mass of what? for the equation

  • @sarahfahdah5008
    @sarahfahdah5008 Рік тому

    thank you

  • @isaniity
    @isaniity 5 місяців тому +1

    im just confused why the arrows point downwards?

  • @astrxlxgy_gd
    @astrxlxgy_gd Місяць тому

    why do we have to use 24cm^3 of water for the hydrated copper (II) sulfate but 25cm^3 of water for the anhydrous copper (II) sulfate?

  • @ghostofday5025
    @ghostofday5025 10 місяців тому

    i am curious as to how the anhydrous copper(ii)sulphate did not react with moisture in air to form hydrous copper(ii)sulphate?

    • @OmniversalInsect
      @OmniversalInsect 7 місяців тому

      I think it did a little bit because the colour is very slightly blue

  • @elettrabelaqua4575
    @elettrabelaqua4575 3 роки тому +1

    I didn't understand the calculations
    How did you get the 159.61 in 4.06/159.61?

    • @llii338
      @llii338 3 роки тому +3

      This is the molar mass for cuso4 and she divided the mass by the molar mass so she gets moles

    • @elettrabelaqua4575
      @elettrabelaqua4575 3 роки тому

      @@llii338 thank you

  • @christabelrwatizha7314
    @christabelrwatizha7314 3 роки тому +5

    This is really proof that not knowing something in this age is out of ignorance because there's so many resources on the internet that tach almost anything

  • @robogecko4067
    @robogecko4067 4 роки тому +5

    The units for Q are J not Jmol-1

  • @killerman-gv1qp
    @killerman-gv1qp 5 років тому +7

    Dear ma'am are these results accurate??

    • @10000subswithnovideos.
      @10000subswithnovideos. 4 роки тому +5

      No.

    • @skerpy8145
      @skerpy8145 4 місяці тому

      everyone gets different results my friend. You are probably in university now so this probably will not help but just saying.

  • @varunraju1569
    @varunraju1569 5 років тому +3

    Is this applicable for CIE AS Level examinations?

  • @rhysstevomusic1338
    @rhysstevomusic1338 2 роки тому +1

    You forgot to minus the q. Everything else is helpful!

  • @papakenny5259
    @papakenny5259 2 роки тому +2

    why didnt you convert the temp to kelvin?

  • @charlotteclaireccastro1573
    @charlotteclaireccastro1573 2 роки тому +7

    didn't understand a word. :) thanks anyways

  • @igetmoreassthanatoiletseat8264
    @igetmoreassthanatoiletseat8264 3 місяці тому

    Ty 4 this girl I'm meant to write a method for this and it's due in 1 hour 😻😻😻