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    Name:  1471952565823-29575917.jpg
Views: 261
Size:  503.0 KBHave I done this right? It seems a bit different from the other diagrams I found. Thanks
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    I don't think you've attached anything for anyone to look at...
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    (Original post by hxfsxh)
    I don't think you've attached anything for anyone to look at...
    Just uploaded it, didn't expect a speedy reply. Thanks
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    (Original post by coconut64)
    Just uploaded it, didn't expect a speedy reply. Thanks
    What exactly are we looking at? The hydroxides look okay, so does the (I'm guessing) calcium.
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    (Original post by alow)
    What exactly are we looking at? The hydroxides look okay, so does the (I'm guessing) calcium.
    Sorry this is just rough work, this is a dot and cross diagram for Ca(OH)2. So I have done it right?
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    (Original post by coconut64)
    Sorry this is just rough work, this is a dot and cross diagram for Ca(OH)2. So I have done it right?
    I'd say so. Why do you think it isn't okay?
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    Name:  Ca(OH)2 diagram.bmp
Views: 579
Size:  423.8 KB
    (Original post by alow)
    I'd say so. Why do you think it isn't okay?
    Hi, this picture seems to show that there is a dative covalent bond between O and H but in my diagram it is a covalent bond so H shares electrons with O. In the picture there are 2 crosses between o and H but in mine it is a dot and a cross.

    The next part of the question ask how many moles of electrons are there in the Oh- ions in this compound. From my diagram, I can only see that there are 8 electrons in the Oh- ion, but the answer is 10 which I am really confused about.

    Thanks
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    (Original post by coconut64)
    Name:  Ca(OH)2 diagram.bmp
Views: 579
Size:  423.8 KB

    Hi, this picture seems to show that there is a dative covalent bond between O and H but in my diagram it is a covalent bond so H shares electrons with O. In the picture it is 2 dots between o and H but in mine it is a dot and a cross.

    The next part of the question ask how many moles of electrons are there in the Oh- ions in this compound. From my diagram, I can only see that there are 8 electrons in the Oh- ion, but the answer is 10 which I am really confused about.

    Thanks
    Yeah the O-H bond definitely should have 1 electron from the hydrogen. The Ca only gives two electrons in total, one to each hydroxide.

    What's the exact wording of the question?
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    (Original post by alow)
    Yeah the O-H bond definitely should have 1 electron from the hydrogen. The Ca only gives two electrons in total, one to each hydroxide.

    What's the exact wording of the question?
    Great. So I believe I have drawn it correctly?
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    (Original post by coconut64)
    Great. So I believe I have drawn it correctly?
    Yeah.
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    (Original post by alow)
    Yeah the O-H bond definitely should have 1 electron from the hydrogen. The Ca only gives two electrons in total, one to each hydroxide.

    What's the exact wording of the question?
    chem question.pdf I am referring to 2b in this picture where it asks about the Ca(Oh)2 compound. I know that there are 3 moles of ions in this compound but I don't get next part of the question 2biii)

    Thanks !
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    (Original post by coconut64)
    chem question.pdf I am referring to 2b in this picture where it asks about the Ca(Oh)2 compound. I know that there are 3 moles of ions in this compound but I don't get next part of the question 2biii)

    Thanks !
    Think about the electron configuration of oxygen. There are 8 valence electrons in a hydroxide ion, but those aren't the only electrons.
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    (Original post by alow)
    Think about the electron configuration of oxygen. There are 8 valence electrons in a hydroxide ion, but those aren't the only electrons.
    Right. So Oh- ion has 8 electrons but since oxygen has 2 more electrons in its inner shell, this is why it adds up to 10?
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    (Original post by coconut64)
    Right. So Oh- ion has 8 electrons but since oxygen has 2 more electrons in its inner shell, this is why it adds up to 10?
    Exactly.
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    (Original post by alow)
    Exactly.
    I don't really get what it actually means by one mole of electrons. Initially, I just did 1*6.02*10^23, do you only do it when it asks for number of atoms in the ions?
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    (Original post by coconut64)
    I don't really get what it actually means by one mole of electrons. Initially, I just did 1*6.02*10^23, do you only do it when it asks for number of atoms in the ions?
    A mole is just an amount. You could have a mole of elephants or a mole of bananas.

    So when you're asked how many moles of something there are in a mole of a compound it's just a case of counting them.
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    (Original post by alow)
    A mole is just an amount. You could have a mole of elephants or a mole of bananas.

    So when you're asked how many moles of something there are in a mole of a compound it's just a case of counting them.
    Thanks so much.
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    (Original post by coconut64)
    Thanks so much.
    No worries
 
 
 
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