Question

Suppose propene (CH2=CH–CH3) is the hydrocarbon that reacts with the hydroxyl radical •OH.

Beginning with addition of •OH, write the set of chemical reactions that ultimately produces an
aldehyde. What is this final aldehyde?


Using the group contribution method determine the kinetic constant for the destruction of
propene by the hydroxyl radical and determine the half life of propene in an urban environment?

Answer 1

To produce an aldehyde from propene, it reacts with a hydroxyl radical, forming an intermediate that eventually becomes propanal. The kinetic constant and half-life of propene's destruction by hydroxyl radicals require specific experimental data, and the half-life can be calculated using first-order kinetics if the rate constant is known.

Step-by-step explanation:

To ultimately produce an aldehyde from propene (CH2=CH-CH3) through reaction with the hydroxyl radical (·OH), the following steps occur:

1. Initiation: The hydroxyl radical adds to one of the carbon atoms in the double bond of propene, generating a free radical intermediate.
2. Propagation: The newly formed radical intermediate reacts with oxygen, forming a new peroxyl radical.
3. The peroxyl radical abstracts a hydrogen atom from another molecule, such as propene itself or another hydrocarbon, leading to the formation of a carbonyl compound (aldehyde).

The final aldehyde in this case is propanal (CH3CH2CHO). Regarding the calculation of the kinetic constant and half-life for the destruction of propene by the hydroxyl radical in an urban environment, this would require specific data such as the rate constant for the reaction and the concentration of radicals, which are typically obtained from experimental or literature values. However, to determine the half-life (t½) of propene, we can use the first-order kinetics formula t½ = ln(2)/k, where k is the rate constant for the reaction.