Question

When phosphine is adsorbed on a molybdenum surface, it decomposes with the metal as a catalyst for the reaction. The half-lives of the decomposition as a function of the initial pressure of phosphine for a constant concentration of catalyst are as follows: 7.6 min/265 torr; 3.7 min/130 torr; 1.7 min/58 torr. Determine the order of the reaction.

Answer 1

Ans-

The expression for K is the product concentrations divided by the
reactant concentrations. When K has a value much less than 1, the
product concentrations are relatively small and the reactant concentrations
are relatively large.When K has a value much greater than 1, the product concentrations
are relatively large and the reactant concentrations are relatively
small. In both cases, however, the rate of the forward reaction equals the rate of the reverse reaction at equilibrium (this is a definition of equilibrium)

An impurity
either adds electrons at an energy near that of the conduction bands
(n-type) or creates holes (unfilled energy levels) at energies in the
previously filled molecular orbitals (p-type). Both n-type and p-type
semiconductors increase conductivity by creating an easier path for
electrons to jump from filled to unfilled energy levels. In conductors,
electrical conductivity is inversely proportional to temperature.
Increases in temperature increase the motions of the atoms, which
gives rise to increased resistance (decreased conductivity). In a semi-
conductor, electrical conductivity is directly proportional to temper-
ature. An increase in temperature provides more electrons with
enough kinetic energy to jump from the filled molecular orbitals