Question

In: Chemistry

NO2 (g) + OH• (g)à HNO3 (g) The rate constant for this reaction is 1.2x10-11 cm3...

NO₂ (g) + OH• (g)à HNO₃ (g)

The rate constant for this reaction is 1.2x10^-11 cm³ molecule^-1s^-1.

Write the rate law for this reaction.
hydroxyl radical concentration in atmosphere is 2.0 x10⁶ molecules cm^-3 at 25 ^oC, find the atmospheric lifetime of NO₂ at 25 ^oC (in hours)
Use the information from first second , determine the concentration of hydroxyl radicals in ppbv at 25 ^oC and 1.0 atm.

Expert Solution

NO₂ (g) + OH^•(g) ==> HNO₃ (g)

The rate constant for this reaction is 1.2x10^-11 cm³ molecule^-1s^-1.

the rate law for this reaction : it is 2nd order reaction ( as also evident from unit of rate constant)

rate = K₂ [NO₂ ][OH^•]

[OH^•] in atmosphere = 2.0 x10⁶ molecules cm^-3 at 25 ^oC,

find the atmospheric lifetime of NO₂ at 25 ^oC:

from 2nd order kinetics , (^T(NO₂)) lifetime of NO₂ can be calculated :

^T(NO₂) = 1/K₂ [NO₂ ][OH^•] = 1/ ((1.2x10^-11 cm³ molecule^-1s^-1)(2.0 x10⁶ molecule cm^-3 ))

^T(NO₂) = 41666.7 sec = 11.57 Hrs.

concentration of hydroxyl radicals in ppbv at 25 ^oC and 1.0 atm:

[OH^•] in atmosphere = 2.0 x10⁶ molecules cm^-3 at 25 ^oC

or in molar terms : 2.0 x10⁶ molecules cm^-3 / 6.023*10²³ molecule/mol = 3.32*10^-18 moles cm^-3

amount of OH^• = 17 g/mol *3.32*10^-18 moles cm^-3 = 5.65 *10^-17 g cm^-3 = 5.65 *10^-11 ug cm^-3

( 1g = 10⁶ microgram (ug))

since 1 ppbv = 1 ug/L ; 1 cm3 = 0.001 L

thus

concentration of hydroxyl radicals in ppbv : 5.65 *10^-8 (ppbv)

queen_honey_blossom answered 2 years ago

The following reaction is first order in N2O5: N2O5(g)→NO3(g)+NO2(g) The rate constant for the reaction at...

The following reaction is first order in N2O5: N2O5(g)→NO3(g)+NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. A. Calculate the rate of the reaction when [N2O5]= 5.9×10−2 M. B. What would the rate of the reaction be at the same concentration as in Part A if the reaction were second order? (Assume the same numerical value for the rate constant with the appropriate units.) C. What would the rate of the reaction be at the same...

The following reaction is first order in N2O5: N2O5(g)?NO3(g)+NO2(g) The rate constant for the reaction at...

The following reaction is first order in N2O5: N2O5(g)?NO3(g)+NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. A) Calculate the rate of the reaction when [N2O5]= 5.4

The equilibrium constant for the reaction SO2(g)+NO2(g)⇌SO3(g)+NO(g) is 3.0. Find the amount of NO2 that must...

The equilibrium constant for the reaction SO2(g)+NO2(g)⇌SO3(g)+NO(g) is 3.0. Find the amount of NO2 that must be added to 2.3 mol of SO2 in order to form 1.1 mol of SO3 at equilibrium.

At a certain temperature, the equilibrium constant, Kc, for this reaction is 2.60 SO2(g) + NO2(g)...

At a certain temperature, the equilibrium constant, Kc, for this reaction is 2.60 SO2(g) + NO2(g) <--> SO3(g) + NO(g) At this temperature, calculate the number of moles of NO2(g) that must be added to 3.12 mol of SO2(g) in order to form 1.30 mol of SO3(g) equilibrium

The reaction: N2O5 (g)  NO3 (g) + NO2 (g) a. Determine the rate order by plotting...

The reaction: N2O5 (g)  NO3 (g) + NO2 (g) a. Determine the rate order by plotting the data. (Hint: Which plot gives a straight line? Conc vs time, ln(conc) vs time, or 1/conc vs time) b. Predict the concentration of N2O5 at 250 seconds. Time (s) [N2O5] 0 1.00 25 0.822 50 0.677 100 0.557 125 0.458 150 0.377

For the reaction NO + O3 → NO2 + O2 the second order rate constant has...

For the reaction NO + O3 → NO2 + O2 the second order rate constant has a value of 1.8x10^-14 molecule-1 cm3 s-1 at 25°C. The concentration of NO in a relatively clean atmosphere is 0.10 ppbv (parts per billion by volume) and that of O3 is 15 ppbv. Calculate these two concentrations in units of molecule cm-3. Calculate the rate of the NO oxidation using concentration units of molecule cm-3. Show how the rate law may be expressed in...

) Consider the reaction A à products. The rate law for this reaction is rate =...

) Consider the reaction A à products. The rate law for this reaction is rate = k[A] where k=7.02 ´ 10-3 M-1 s-1 at a particular temperature. If the initial [A] = 0.0500 M, what is the initial rate? What is the value of the half-life for this initial concentration of A? What will be the half-life if the initial [A] = 0.0250 M What will be the half-life if the initial [A] = 0.100 M What will be the...

Consider this reaction: H2(g) + O2 (g) à H2O (g) &nbsp

Consider this reaction: H2(g) + O2 (g) à H2O (g) dHo = __________ Balance the equation and put the correct number of moles in the equation above. (1 point) Classify the forward reaction as (1) Combustion, (2) Decomposition, (3) Single replacement, (4) Double replacement, (5) Neutralization, (6) Synthesis. Circle the correct answer. (1 point) In this reaction did Hydrogen get oxidized or reduced? Circle the correct answer. (1 point) Based on your answer above is Hydrogen an...

Consider the reaction: 2 NO2 (g) ⇌ N2O4 (g) The ΔGf° for NO2 (g) = 52...

Consider the reaction: 2 NO2 (g) ⇌ N2O4 (g) The ΔGf° for NO2 (g) = 52 kJ/mol and for N2O4 (g) = 98 kJ/mol at 298 K. Calculate the ΔG at the following values. 0.8 M NO2 (g) & 3.0 M N2O4 (g) 4.0 M NO2 (g) & 0.9 M N2O4 (g) 2.2 M NO2 (g) & 2.4 M N2O4 (g) 2.4 M NO2 (g) & 2.2 M N2O4 (g)

The reaction NO(g) + O3 -> NO2(g) + O2(g

The reaction NO(g) + O3 -> NO2(g) + O2(g) was studied in 2 experiments under pseudo-first order conditions. a) [O3] = 1x1014 molecules/cc in excess the [NO] varied as follows {Note, time is in msec (1 msec = 1x10-3 s)!} time (msec) NO (molecules/cc) 0 6x108 100 5x108 500 2.4x108 700 1.7x108 1000 9.9x107 b) [NO] = 2x1014 molecules/cc in excess time (msec) O3 (molecules/cc) 0 1x1010 50 8.4x109 ...