Chapter 9, Problem 9.125QP

The hydroxyl radical (OH) plays an important role in atmospheric chemistry. It is highly reactive and has a tendency to combine with a H atom from other compounds, causing them to break up. Thus, OH is sometimes called a “detergent” radical because it helps to clean up the atmosphere. (a) Write the Lewis structure for the radical. (b) Refer to Table 9.4 and explain why the radical has a high affinity for H atoms. (c) Estimate the enthalpy change for the reaction

$\text{OH}(g)+{\text{CH}}_4(g)\stackrel{}{\to }{\text{CH}}_3(g)+{\text{H}}_2\text{O}(g)$

(d) The radical is generated when sunlight hits water vapor. Calculate the maximum wavelength (in nanometers) required to break an O─H bond in H₂O.