(Original post by Bulldog1965)
hi thankyou chemistry is not my strong point. as im 50 and never did chemistry in 1978 at school and now going to university 1st year engineering but i have to get this module out of the road and its confusing at best.
So the structural formula is CLC2C2HF ? arghhh the notes on blackboard is so confusing - ppts
Ah I understand. Your answer is incorrect.
The answer is CH2ClCHClCHFCH3
Here's some points you will find helpful:
-Carbon atoms will always make 4 bonds.
- hydrogen atoms will bond only once.
- Carbons atoms will bond with each other to make the main body of the compound: C-C-C-C
- The carbon atoms will bind to hydrogen atoms so they meet the required 4 bond criteria. But they will also bind the other atoms if specified like the compound you are asking about. The important thing to remember is that the carbon atom must make 4 bonds.
- The numbers in the compound's name will tell you the position of that particular group/atom in the compound
So here's our compound :
1, 2- dichloro-3-florobutane
To make it easier break up the name into parts:
= The main carbon chain has 4 carbon atoms.Remember each carbon atom will form 4 bonds
= Ok so there's 1 chlorine on the first carbon atom and another chlorine on the second carbon atom.
So for carbon 1 and 2 we have CCl-CCl but remember the carbons must make 4 bonds. The first carbon is bonded to the chlorine and the second carbon = 2bonds, so we add to hydrogen atoms to it to get 4 bonds : CH2Cl
The second carbon is bonded to the first carbon and a chlorine and ALSO the third carbon = 3 bonds. So we add a hydrogen to the second carbon to get 4 bonds : CH2Cl -C
HCl - C
The second carbon is in bold and the dashes show that its bonded to 2 other carbons ( Don't put dashes in the answer, I;ve just done it to so its easier to understand)
= one fluorine atom on the third carbon = CF. But the 3rd carbon is also bonded to the second and fourth carbon = 3 bonds. So we add a hydrogen to get 4 bonds= CH2Cl -CHCl -C
The compound name does't specifiy anything about the fourth carbon but we know it must be bonded to the 3rd carbon atom so we add 3 hydrogen atoms to get 4 bonds: CH2Cl -CHCl -CHF- C
Now remove the dashes to get :