Starter

1)Write an equation for the reaction between methanol and butanoic acid. Name the organic product formed.

2) Name the following compoundsa)CH3CH2CH2CHClCH3

b)CH3CH2CHBrCHClCH

Halogenoalkanes

L.O.:

Describe the structure, general formula and uses of halogenoalkanes.

Describe and explain the nature of the carbon–halogen bond and its susceptibility to nucleophilic attack.

Define the term nucleophile as an electron pair donor

In pairs:a)Explain which is the most electronegative

atom.b)Explain the trend of electronegativity in

group 7.c) Explain why the C-Cl bond is polar.d)Which of these bonds is more polar: C-F, C-Cl,

C-Br, C-I.

Polarity of the carbon-halogen bond

Polarity of the carbon-halogen bond decreases down the group

Reactions of haloalkanesL.O.:

Describe the hydrolysis of halogenoalkanes as a nucleophilic substitution reaction.

Describe the mechanism of nucleophilic substitution in the hydrolysis of primary halogenoalkanes with hot aqueous alkali.

Explain the rates of primary halogenoalkane hydrolysis in terms of the relative bond enthalpies of carbon–halogen bonds.

In pairs

1) What is a nucleophile?

2) Examples of nucleophiles.

Mechanism for nucleophilic substitution

Curly arrows are used to represent the movement of electron pairs

In pairs:

1)Predict the relative rate of hydrolysis of :R-Cl, R-Br and R-I

Bond Bond enthalpy (KJ mol-1)C-F +467C-Cl +340C-Br + 280C-I +240

Rates of hydrolysis of halogenoalkanes

In hydrolysis of halogenoalkanes, the bond enthalpy is more important that bond polarity.

Reactions of haloalkanesL.O.:

Describe the hydrolysis of halogenoalkanes as a nucleophilic substitution reaction.

Describe the mechanism of nucleophilic substitution in the hydrolysis of primary halogenoalkanes with hot aqueous alkali.

Explain the rates of primary halogenoalkane hydrolysis in terms of the relative bond enthalpies of carbon–halogen bonds.