Explain the following facts indicating what each value of means and outline the necessary mechanisms. a) The ionization of substituted benzoic acids in water

Explain the following facts indicating what each value of ρ means and outline the necessary mechanisms.

a) The ionization of substituted benzoic acids in water has by definition a value of ρ = 1. However, when measured in 40% aqueous-ethanol ρ = 1.7.

b) The value of ρ for the nucleophilic substitution of benzyl chlorides with various substituents on the aromatic ring and carried out in water with hydroxide is -0.3, while with iodide in acetone it is 0.8. Explain the difference in the value of ρ.

c) Why is the value of ???? of the -OH group (+) when it is in the meta position on the benzene ring and (-) when it is in the para position?

d) Alkaline hydrolysis of ring-substituted methyl benzoates has a ρ =2.2

e) The reaction of anilines substituted on the aromatic ring with benzoyl chloride in benzene at 25°C has ρ=2.8. Could you predict what would be the effect of the polarity of the solvent on ρ.
 
 
 

benzyl chloride benzyl chloride OH HO T acetona www. OH + CI p = -0.3 + CI p = 0.8