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# Electron help??

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1. I have done this paper so many times but never understood why it's 18 electrons, getting really confused.
2. (Original post by Hazel99)

I have done this paper so many times but never understood why it's 18 electrons, getting really confused.
whats the thing at the end of the F?
3. (Original post by Hazel99)

I have done this paper so many times but never understood why it's 18 electrons, getting really confused.
Think of how many electrons carbon and fluorine have, it isn't 12 and 18 respectively...
4. (Original post by CheeseIsVeg)
whats the thing at the end of the F?
First one is a subscript 2 and the second one is a period.
5. (Original post by Kvothe the Arcane)
First one is a subscript 2 and the second one is a period.
Pretty sure it's a single fluorine as neutral carbon only makes 4 bonds.
6. (Original post by Plantagenet Crown)
Pretty sure it's a single fluorine as neutral carbon only makes 4 bonds.
From part (a). Referring to diatomic Florine.
7. (Original post by CheeseIsVeg)
whats the thing at the end of the F?
It's just CH3F
8. Actually I have worked it out lol
C=6 electrons
H(x3)=3
F=9

= 18 XD
9. (Original post by Hazel99)
Actually I have worked it out lol
C=6 electrons
H(x3)=3
F=9

= 18 XD
Yeah you were using atomic masses..
10. (Original post by mandeep_nagra)
10.0g of a mixture of sodium hydroxide and sodium chloride were dissolved in water. This mixture was titrated with sulfuric acid of concentration 0.500 mol dm-3. 52.10cm^3 of the acid was required for neutralisation. The equation as follows of:

2NaOH + H2SO4 ---> Na2SO4 + 2H2O

1) Calculate the number of moles of sulfuric acid required for neutralization
2)Hence deduce the number of moles of sodium hydroxide in the solution
3)Calculate the mass of sodium hydroxide
4) Hence find the percentage of sodium hydroxide in the original sample

Thank you
What have you tried?
11. (Original post by Hazel99)

I have done this paper so many times but never understood why it's 18 electrons, getting really confused.
*

The number of electrons in a molecule depends on the number of electrons in every single atom of the molecule (also the ones which are exist more than once).*

Carbon (C) has 6 electrons, Hydrogen (H) has one electrons and this atom exists thrice, Fluorine has nine ones. That is why:*

6 + 3x1 + 9 = 18.

So this molecule has 18 electrons in total. *

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