[SciG07]

How does that affect rate of hydrolysis?

C-Cl
C-Br
C-I

Ethanol - Nucleophile
Alkane: Butane (ie. 1-Chlorobutane)

Iodide would be the most stable, but im not sure how to back it up and talk about rate of hydrolysis.

[AhmedEzatAlzawalaty]

nucleophile is RO(-) so it attacks the C of C????X since C-Cl>C-Br>C-I bond strength i would expect that rate of attack woul be from I to Cl. and so rate of hydrolysis

[SciG07]

Oh ok.

What can i talk about "Induction" ?

I know i keep the butane chain constnat but anything else?

[xiankai]

hydrolysis involves cleavage of the C-Hal bond, and if the bond is weaker, would it not be easier and thus faster to break it?

[SciG07]

hydrolysis involves cleavage of the C-Hal bond, and if the bond is weaker, would it not be easier and thus faster to break it?

Yes, but thats bond enthaply.. Hence C-I would be the easiest to break. How does stablity of the bond come into this? The more stable it is the easier it's broken?! Thanks.

[SciG07]

How does whether the reaction is SN1 or Sn2 affect rate of hydrolysis? I know that one is one step and the other is two, but anything else?

[maakii]

An SN1 reaction involves mainly tertiary alkyl halides, while an SN2 reaction involves mainly primary alkyl halides.

However, in both mechanisms, the rate determining step involves the cleavage of the C-Hal bond.

 In SN1, the rate determining step is where the C-Hal bond is broken to form C+ (carbocation) and Hal^-. In SN2, the rate determining step is a concerted reaction, where the nucleophile attacks and the Halogen atom is displaced at the same time. Thus, in both mechanisms, weaker C-Hal bonds (ie less stable, and lower bond enthalpy) will increase the rate of reaction.

Now, which of the C-Hal bonds is lowest bond enthalpy and is thus weakest?

[edwinksl]

How does that affect rate of hydrolysis?

C-Cl
C-Br
C-I

Ethanol - Nucleophile
Alkane: Butane (ie. 1-Chlorobutane)

Iodide would be the most stable, but im not sure how to back it up and talk about rate of hydrolysis.

While the bond enthalpy is definitely a factor to consider, I believe that I-, being the best leaving group among the halides, helps to increase the rate of hydrolysis as well.

[xiankai]

How does stablity of the bond come into this?

the more stable it is, the harder it is to make it break. when it is harder to break, you will take longer than usual to break it. thus this lowers the rate of hydrolysis. the C-I bond is particularly weak and thus easy to break (increasing rate of hydrolysis), because the ionic radius of I^- is so large, thus the bond length is pretty long. attraction between the two elements is greatly reduced in comparison to the other smaller halides.