Interpretation:
To understand the role of
Concept Introduction:
Different mechanisms and different rate of reactions are responsible for contrasting level of ozone concentrations in troposphere and stratosphere.
Answer to Problem 1CO
Ozone and other pollutants form in the troposphere due to different rate of reactions involved.
Explanation of Solution
Ozone also formed at ground level but the mechanism and kinetics are very different from that in upper atmosphere. The formation of ozone in smog comprises several steps. The oxide of nitrogen
When NO2 absorbs sunlight, it dissociates to:
The oxygen atom generated by this reaction can now form ozone:
Thus, formed ozone will quickly react with NO:
This reaction is much faster so ozone is unlikely to form if no other compound reacts with NO to consume it and make it unavailable for dissociation of ozone. The chemical which can consume NO are volatile organic compounds (VOC). Most of the VOC’s are industrial solvents.
The reactions to remove NO are much faster than the reaction of NO with O3. Thus, in the presence of sunlight smog can form along with ozone.
Ozone is also a pollutant at concentrations higher than 1 ppm along with other oxides of nitrogen and sulphur.
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Chapter 11 Solutions
EBK CHEMISTRY FOR ENGINEERING STUDENTS,
- Silicon forms a series of compounds analogous to the al-kanes and having the general formula SinH2n+2. The first of these compounds is silane, SiH4, which is used in the electronics industry to produce thin ultrapure silicon films. SiH4(g) is somewhat difficult to work with because it is py-ropboric at room temperature—meaning that it bursts into flame spontaneously when exposed to air. (a) Write an equation for the combustion of SiH4(g). (The reaction is analogous to hydrocarbon combustion, and SiO2 is a solid under standard conditions. Assume the water produced will be a gas.) (b) Use the data from Appendix E to calculate ? for this reaction. (c) Calculate G and show that the reaction is spontaneous at 25°C. (d) Compare G for this reaction to the combustion of methane. (See the previous problem.) Are the reactions in these two exercises enthalpy or entropy driven? Explain.arrow_forwardAmoxicillin is an antibiotic packaged as a powder. When it is used to treat babies and small animals, the pharmacist or veterinarian must suspend it in water, so that it can be administered orally with a medicine dropper. The label says to dispose of unused suspension after 14 days. It also points out that refrigeration is required. In the context of this chapter, what is implied in the latter two statements?arrow_forwardGive practical applications of chemical kinetics-related concepts in real life.arrow_forward
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- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning