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    (Original post by MerishaX)
    Why does ionization energies decrease from one period to another? Thanks in advance
    Atomic/ionic radius increases, so there are weaker forces of attraction between valence electrons and the nucleus.
    Shielding also increases, weakening the force between the nucleus and the outermost electrons.
    Nuclear charge increases, but this is less significant than the radius increase, so an overall decrease x
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    (Original post by Bloom77)
    I'm feeling okay until now
    I don't think I'm ready yet whoops
    Glad I have the whole day tomorrow
    Have you got a list of definitions?


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    They're not all definitions. They're basically taken from different exam papers.


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    Any tips to remember the names of the shapes of molecules?
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    (Original post by AdamWallisjr)
    Any tips to remember the names of the shapes of molecules?
    Old grannies licking *******s anally
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    Do we have to know about adsorption and desorption for catalytic converters or is that just my textbook being overly pedantic?
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    (Original post by swagdaddy123)
    Do we have to know about adsorption and desorption for catalytic converters or is that just my textbook being overly pedantic?
    I haven't heard of this....I think its just your textbook...Hopefully...
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    (Original post by swagdaddy123)
    Do we have to know about adsorption and desorption for catalytic converters or is that just my textbook being overly pedantic?
    For A2 modular a level chemistry you do
    Not sure for the new syllabus


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    (Original post by Junaidc122)
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    They're not all definitions. They're basically taken from different exam papers.


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    Thank you


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    (Original post by swagdaddy123)
    Do we have to know about adsorption and desorption for catalytic converters or is that just my textbook being overly pedantic?
    This is an A2 topic I believe, either way, it wouldn't be in this exam, as this is inorganic, the next one is organic, and contains everything to do with Alkanes, and then the environmental problems that they cause.
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    (Original post by Bloom77)
    Same here
    I think it would definitely be harder than usual.
    I'm only retaking unit 1, wbu?
    We all wish we were doing your exams :P The papers are so much nicer for the old spec!
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    (Original post by swagdaddy123)
    Do we have to know about adsorption and desorption for catalytic converters or is that just my textbook being overly pedantic?
    I'm not sure because I haven't seen any past papers that ask about adsorption and desorption but I've learned it just in case
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    I'm terrified for tomorrow, I don't know anywhere near enough 😖 Good luck everyone!
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    Boron trichloride (BCl3) can be prepared as shown by the following equation.
    B2O3(s) + 3C(s) + 3Cl2(g) --> 2BCl3(g) + 3CO(g)

    A sample of boron oxide (B2O3) was reacted completely with carbon and chlorine. The two gases produced occupied a total volume of 5000 cm3 at a pressure of 100 kPaand a temperature of 298 K. Calculate the mass of boron oxide that reacted.

    Give your answer to 3 significant figures.
    (The gas constant R = 8.31 J K–1 mol–1)


    THE ANSWER IS: 2.81 (g)

    Can anyone explain why once you work out the mols of chlorine and carbon, you divide by 5? I thought it would have been 6 because its a ratio of 1 : 6.
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    Does anyone know which practicals can come up in the unit 1 exam?

    Is it just Making up a volumetric solution, measuring an enthalpy change and testing for ions?
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    (Original post by ajsullivan)
    Will_5054

    check out www.scienceskool.co.uk

    Exams section.

    Good luck

    Alex
    The exam section is password protected, any chance you know the password?
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    (Original post by Cakey_101)
    Boron trichloride (BCl3) can be prepared as shown by the following equation.
    B2O3(s) + 3C(s) + 3Cl2(g) --> 2BCl3(g) + 3CO(g)

    A sample of boron oxide (B2O3) was reacted completely with carbon and chlorine. The two gases produced occupied a total volume of 5000 cm3 at a pressure of 100 kPaand a temperature of 298 K. Calculate the mass of boron oxide that reacted.

    Give your answer to 3 significant figures.
    (The gas constant R = 8.31 J K–1 mol–1)


    THE ANSWER IS: 2.81 (g)

    Can anyone explain why once you work out the mols of chlorine and carbon, you divide by 5? I thought it would have been 6 because its a ratio of 1 : 6.
    Once you have the total number of moles of gas which is 5 (3+2), to find the number of moles of B2O3, just divide by 5 which should give a value of around 0.04038
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    (Original post by Turtlebunny)
    We all wish we were doing your exams :P The papers are so much nicer for the old spec!
    Haha, same here just so the grade boundaries would be the as usual
    However, specimen papers are always harder than the real thing so take that into account
    Even the old spec paper was more difficult than the papers that have been released


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    (Original post by Bloom77)
    Haha, same here just so the grade boundaries would be the as usual
    However, specimen papers are always harder than the real thing so take that into account
    Even the old spec paper was more difficult than the papers that have been released


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    Yeah, its most likely our grade boundaries will go down because its a new spec and its meant to be harder, but unfortunately your boundaries will probably go up since everyone whos doing it is an A2 student so they'll all be good at it
    I wish you luck tomorrow
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    (Original post by KD1024)
    The exam section is password protected, any chance you know the password?
    Sadly I was forced to do this. If you are interested in the reasoning you can read my blog post. http://www.scienceskool.co.uk/blog

    The site still has notes, questions and answers which I am sure you will find useful.

    Best of luck

    Alex
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    (Original post by Cakey_101)
    Boron trichloride (BCl3) can be prepared as shown by the following equation.
    B2O3(s) + 3C(s) + 3Cl2(g) --> 2BCl3(g) + 3CO(g)

    A sample of boron oxide (B2O3) was reacted completely with carbon and chlorine. The two gases produced occupied a total volume of 5000 cm3 at a pressure of 100 kPaand a temperature of 298 K. Calculate the mass of boron oxide that reacted.

    Give your answer to 3 significant figures.
    (The gas constant R = 8.31 J K–1 mol–1)


    THE ANSWER IS: 2.81 (g)

    Can anyone explain why once you work out the mols of chlorine and carbon, you divide by 5? I thought it would have been 6 because its a ratio of 1 : 6.
    The moles of gases formed is 5. The moles of boron oxide is 1. Therefore, it is a 1:5 ratio. Therefore, you divide by 5
 
 
 
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