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# Shapes of Molecules QUESTIONS!

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1. Describe the structure and bond angle in C2H3Cl

I don't know how to work this out!

anyone got any ideas?
2. i think the bond angles around each carbon are 107.5 and based on tetrahedral...but im not 100% sure
3. it has a bond angle of 120 but i don't know why.
4. i think it's an alkene, where the 2 C are double bonded to each other and 2 H on 1 C & 1 H and 1 Cl on other C
5. (Original post by Scapepicture)
it has a bond angle of 120 but i don't know why.
ah yes, my bad, its a trigonal planar molcule because it has a double bond, so each carbon is bonded to essentially 3 other atoms (count the C=C double bond as one bond)

so 3 bonds = trigonal planar = bond angle of 120
6. C2H3CL is Chloroethene. Its got a double bond between the carbon atoms.

I can see why its 120 degrees between each bond because the carbon atom has one double bond and 2 single bonds coming off it. Therfore for maximum seperation - 120.
7. (Original post by Scapepicture)
Describe the structure and bond angle in C2H3Cl

I don't know how to work this out!

anyone got any ideas?
It looks like this:
.....

.....h..h
.....!...!
.....c=c
.....!...!
.....h...cl

This is better:

Each Carbon is in the chape of a trigonal planar and has a bond angle of 120 degrees. Now can you see?
Always draw them out first.
8. (Original post by viksta1000)
ah yes, my bad, its a trigonal planar molcule because it has a double bond, so each carbon is bonded to essentially 3 other atoms (count the C=C double bond as one bond)

so 3 bonds = trigonal planar = bond angle of 120
This could be misleading when it comes to lone pairs of electrons.
9. it's 107, pyramidal around the carbon atoms fullstop.
10. (Original post by Rassam)
it's 107, pyramidal around the carbon atoms fullstop.
No it's not.
11. (Original post by nazirard)
No it's not.
My bad, Carbon has 4 not 5 electrons, so it would be slightly smaller than a triganol planar shape so about 119.
12. (Original post by Rassam)
My bad, Carbon has 4 not 5 electrons, so it would be slightly smaller than a triganol planar shape so about 119.
Having 4 bonds and no lone pairs would make it 107 degrees not 119.
Because of the double bond with the neighbouring carbon atom you get "3 bonds" if you must in the carbon atoms. Thus the bond angle around each carbon atom is 120 degrees so it must be a trigonal planar.
13. (Original post by Rassam)
My bad, Carbon has 4 not 5 electrons, so it would be slightly smaller than a triganol planar shape so about 119.
A neutral carbon atom has 6 electrons.

/pedantry
14. (Original post by JayEm)
A neutral carbon atom has 6 electrons.

/pedant
Carbon has 4 electrons on it's outer shell.
15. (Original post by nazirard)
Carbon has 4 electrons on it's outer shell.
Yes that's correct but that's not what I said.
16. (Original post by JayEm)
Yes that's correct but that's not what I said.
Correct. Apologies.
17. (Original post by JayEm)
A neutral carbon atom has 6 electrons.

/pedantry
6? thats not what my periodic table says...
18. (Original post by Rassam)
6? thats not what my periodic table says...
In total.
19. (Original post by Rassam)
6? thats not what my periodic table says...

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