Hydrogen has three isotopes, protium, `""_(1)^(1)H`, deuterium, `""_(1)^(2)H`or Dand tritium, `""_(1)^(3)H` or T, which differ from one another in the number of neutrons. Naturally occuring hydrogen contains 99.986% of the `""_(1)^(1)H` isotope, 0.014% of `""_(1)^(2)H` and `7 xx 10^(-16)% `of `""_(1)^(3)H`,so, the properties of hydrogen are essentially those of the lightest isotope. Protium is by far the most abundant and tritium is radioactive and decays by Bemission. Their only difference in chemical properties are the rates of reactions and equilibrium constants.
Which of the following pairs shows maximum isotope effect?

Options

A. `""_(1)^(1)H` and `""_(1)^(2)D`
B. `""_(17)^(35)CI` and `""_(17)^(37)CI`
C. `""_(6)^(12)C `and `""_(6)^(14)C`
D. None of these

Answer

A

Explanation

A Protium `(""_(1)^(1)H)`and deuterium `(""_(1)^(2)D)` pairs show maximum isotopic effect. Protium reacts with chlorine nearly 13.4 times faster than deuterium.
It is adsorbed more readily on activated charcoal than deuterium.