DJA 3). Mecanisms simple editor Flashcards Preview

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Flashcards in DJA 3). Mecanisms simple editor Deck (17)
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1
Q

free radical

A

A chemical species with an unpaired electron - usually highly reactive`

2
Q

how many stages to free radical substitution

A

3

3
Q

what are the stages of free radical substitution (short)

A

initiationpropagationtermination

4
Q

initiation

A

free radicals are producedCl2 ——-> •Cl +•Cl

5
Q

Propagation

A

‘Recycling the free radical’a). Cl• + CH3CH3——–> CH3•CH2 + HCl (dot usually above C)b). CH3•CH2 + Cl2—–> CH3CH2Cl + Cl•free radical used and then reformed

6
Q

Termination

A

Two free radicals collidingCH3•CH2+ Cl• ——->CH3CH2ClCl• + Cl• ——–> NO JUST REFORMS WITH UV LIGHTCH3•CH2 +CH3•CH2——-> CH3CH2CH2CH3

7
Q

Further substitution

A

If Cl2is in excess then the product will react with more and more Cl2.Then that new product wil react with more Cl2and so on….

8
Q

what is a nucleophile

A

a species that contains a lone pair of electrons

9
Q

3 examples of nucleophiles correctly written

A

negative (xx) OH(xx) NH3negative (xx) CN

10
Q

What happens during nucleophlic substitution

A

The nucleophile will swap places with another nucleophile on a molecule

11
Q

Least reactive haloalkane

A

fluoro….

12
Q

most freactive haloalkane

A

iodo…..

13
Q

strongest haloalkane bond

A

fluoro….

14
Q

weakest haloalkane bond

A

iodo…

15
Q

explanation for strongest bond

A

shortest bond, electron pair in the bond is closest to the nucleus of F and there is little shielding therefore it is more strongly attracted

16
Q

explanation for weakest bond

A

longest bond, electron pair in covalent bond is further away from the nucleus and there is more shielding so held less strongly

17
Q

elimintaionwhat does negative (xx) OH act as

A

a base