Concept explainers
Peroxyacetyl nitrate (PAN) undergoes thermal decomposition as follows:
The rate constant is
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Chemistry
- Be sure to answer all parts. Nitric oxide occurs in the tropospheric nitrogen cycle, but it destroys ozone in the stratosphere. (a) Write equations for its reaction with ozone and for the reverse reaction. Include the physical states of the reactants and products. Forward reaction: Reverse reaction: (b) Given that the forward and reverse steps are first order in each component, write general rate laws for them. Let kç be the rate constant of the forward reaction and k. the rate constant of the reverse reaction. Forward rate law: Rate= kf Reverse rate law: Rate, = k, (c) Calculate AG for the forward reaction at 280. K, the average temperature in the stratosphere. (Assume that the AH and S values do not change with temperature.) kJarrow_forward4) Hydrogen peroxide decomposes spontaneously slowly to form water and oxygen gas according to the following chemical equation: 2 H,0, () — 2 Н,0 ()+ Oz (g) 2 H2O (I)+ O2 (g) This decomposition can be sped up with the addition of a catalyst. If 198 mL of H2O2 decomposes and the amount of oxygen gas collected over water is 72.5 L at 756 mmHg and 23°C, calculate the gas constant, R. (assume: PH,0, = 1.0 mL -9-)arrow_forwardO3 is produced in the troposphere through the photochemical oxidation of NO2. The photolytically formed O3 reacts with NO to regenerate NO2through the following reaction:O3(g) + NO(g) → NO2(g) + O2(g) Calculate the equilibrium constant (K) of the reaction at 100 °C and 1 atm.arrow_forward
- Assume that the formation of nitrogen dioxide: 2NO(g) + O2(g) 2NO2(g) is an elementary reaction. (a) Write the rate law for this reaction. (b) A sample of air at a certain temperature is contaminated with 2.0 ppm of NO by volume. Under these conditions, can the rate law be simplified? If so, write the simplified rate law. (c) Under the conditions described in part (b), the half-life of the reaction has been estimated to be 6.4 × 103 min. What would the half-life be if the initial concentration of NO were 10 ppm?arrow_forwardAverage ozone concentrations in Jakarta, Indonesia have been reported to be 0.015 mg m^-3 and in Tokyo, Japan are 20 ppbv. What is the approximate ratio of these two values when expressed in the same units?arrow_forwardExplain the relevance of the 1987 Montreal Protocol and its 2016 Kigali Amendment on regulating ozone depletion.arrow_forward
- (a) What is the difference between chlorofluorocarbonsand hydrofluorocarbons? (b) Why are hydrofluorocarbonspotentially less harmful to the ozone layer than CFCs?arrow_forwardExplain the different mechanisms by which ozone is formed in the troposphere as a pollutant and in the stratosphere as a protective shield.arrow_forwardThe solid rocket propellant for the Space Shuttle (and Tomahawk Missiles) contain ammonium perchlorate, NH,CIO4(s) , and aluminum powder, Als) bound together with polymer (rubber) compound. The reaction that provides the thrust for these engines is given below: 6 NH4CIO4(s) + 10 Al(s) → 4 Al203(s) + 2 AlCl3(s) + 12 H2O(g) + 3 N2(9) ; AHº, rxn ΔΗΡ -289 kJ/mol 0.0 kJ/mol -1675.5 kJ/mol -705.6 kJ/mol -241.8 kJ/mol 0.0 kJ/mol Use the enthalpies of formation (AHº;) to calculate the change in enthalpy, AH® x, for this reaction (~ 6 mols of NH4CIO4(s). AH°, [ Select ] kJ/ 6 mol NH4CIO4(5) rxnarrow_forward
- Chemistry for Engineering StudentsChemistryISBN:9781285199023Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning