Chemistry 102: Kinetics: Concentration of Half-Life

Question

Chlorine monoxide accumulates in the stratosphere above Antarctica each winter and plays a key role in the formation of the ozone hole above the South Pole each spring. Eventually, ClO decomposes according to the equation:

2ClO(g)Cl2​(g)+O2​(g)

The second-order rate constant for the decomposition of ClO is 7.08×10⁹ M^–1s^–1 at a particular temperature. Determine the half-life of ClO when its initial concentration is 1.41×10^-8 M .

Answer 1

Hi Katelyn! So for a second order reaction, the half life is given:

t1/2 = 1/(k* [A]0)

where k is the rate constant and [A]0 is the initial concentration. Therefore:

t1/2 = 1/(7.08 x 10^9M-1s-1 * 1.41 x 10^-8 M) = 0.0100 s

I hope this helps!