Question

Orgasic Chemistry Experiments Laberatory Manuais (CHM 221L and 22111 (C) Steric Hindrance EXPLAIN these observations. 4. What is the OBSERVED change in the rate of reaction with AgNO3 in alcohol caused by each of the following? (Cite experimental evidence.) (A) Nature of halogen (C, Br) (B) Extent of branching of RX nofto sd to 6onsbhs tamgs s (C) Steric hindrance

Answer 1

Q4) A) Alkyl halide AgNO3 in ethanol give reaction via SN1 mechanism. Br- is better leaving group than the Cl- hence reaction with alkyl bromide is faster than the alkyl chloride. B) As the reaction follows SN1 mechanism, the reactivity order is: 3° 2° 1°. So as branching increases at the reactive carbon reactivity increases. C) In the SN1 reaction alkyl halide gives a carbocation intermediate by breaking of C-X bond. And then further the nucleophile in this case ethanol attacks to the carbocation to give the product. The carbocation is a planer intermediate as the carbon is sp2 hybridized and hence steric hindrance does not affect much on the rate of the reaction Please note that it may not be possible to cite experimental evidences as your experimental observations are not given. However, I have provided general observations and should be true for most of the cases.