Question

List 3 possible reasons why a person might not observe a reaction even when the activity series indicates that it should. Please explain carefully. Thank you for your help.

Answer 1

ELECTRONIC EFFECT=>

Considering one particular electronic enviornment of a reactant in substrate there may present more than one reactive centre which can interfere with the reactant significantly. And also due to presence of different groups or electronic enviornment, electronic repulsion an attraction which is the so called electronic effect comes into picture, then what we are expecting that a particular group will be attacked by reactant may not due to above mentioned electronic effects.

STERIC EFFECT=>

Its very much needed that reactant and substrate should come closer otherwise bond breaking/making is impossible. Now this close proximity is a serious problem in case of larger molecules. As there reactant cant approach towards steric substrate due to steric bulk in the molecule then instead of present of active group reaction cant be forward.

SOLUBILITY PROBLEM=>

To proceed a reaction we have to take reactant and substrate in a same medium(solvent) otherwise no interaction between them will take place. Now many times its observed that there is a issue in solubility in a particular medium of both reactant & substrate. for this reason also reaction might not observed.