Question

Deuterium is the isotope of hydrogen of mass number 2, with a proton and a neutron in its nucleus. The chemistry of deuterium is nearly identical to the chemistry of hydrogen, except that C−D bond is slightly (5.0KJ/mole) stonger than the C−H bond. Reaction rates tend to be slower if a C−D bond as opposed to a C−H bond is broken in a rate limiting step. This effect on the rate is called a kinetic isotope effect.
a. True
b. False

Answer 1

Answer:

True

Explanation:

We know that the zero-point-energy of a C-D system is quite lower than the zero point energy of the C-H bond so the C-D bond is stronger.

Kinetic isotope effect refers to the change in the rate of reaction owing to a change of one of the atoms of the reactants by replacing it with one of its isotopes.

Since we know that the C-D bond is stronger than the C-H bond, when we replace hydrogen with deuterium in a reaction's rate determining step we experience a little lag in the rate of reaction. This is referred to as the kinetic isotope effect in physical organic chemistry.