Consider the formation of HI from and in the gas phase
CHEMISTRY · Single correct · A Level · Chemistry · Kinetics · Kinetics
Problem
Consider the formation of HI from H2 and I2 in the gas phase. Two individual collisions are described below.
Collision X: An H2 molecule approaches an I2 molecule end-to-end so that one H atom is pointed directly at one I atom.
Collision Y: The same H2 molecule approaches the midpoint of the I2 molecule at a right angle (side-on).
Which statement about the likelihood of these collisions leading to product formation best reflects kinetic theory?
(a) Only Collision Y is likely to produce HI because it maximizes the surface contact between H2 and I2, allowing bonds to break simultaneously.
(b) Both collisions are unlikely to produce HI because breaking two bonds and forming two new ones is statistically improbable in a single collision.
(c) Only Collision X is likely to produce HI because it aligns the atoms that must exchange bonds.
(d) Both collisions will produce HI with equal probability as long as the temperature is high enough, since collision energy is the dominant factor.