Dinitrogen pentoxide (N2O5) decomposes in chloroform as a solvent to yield NO2 a
ID: 495029 • Letter: D
Question
Dinitrogen pentoxide (N2O5) decomposes in chloroform as a solvent to yield NO2 and O2. The decomposition is first order with a rate constant at 45 C of 1.0×105s1.
Part A
Calculate the partial pressure of O2 produced from 1.44 L of 0.543 M N2O5 solution at 45 C over a period of 15.0 h if the gas is collected in a 12.6-L container. (Assume that the products do not dissolve in chloroform.)
Dinitrogen pentoxide (N2O5) decomposes in chloroform as a solvent to yield NO2 and O2. The decomposition is first order with a rate constant at 45 C of 1.0×105s1.
Part A
Calculate the partial pressure of O2 produced from 1.44 L of 0.543 M N2O5 solution at 45 C over a period of 15.0 h if the gas is collected in a 12.6-L container. (Assume that the products do not dissolve in chloroform.)
Explanation / Answer
N2O5---à 2NO2 +1/2O2
-d[N2O5]/dt= K[N2O5] = 1*10-5[N2O5]
When integrated [N2O5] = [N2O5]0* exp(-1*10-5*t)
[N2O5]0 = concentration of N2O5 at zero time and [N2O5] is concentration of N2O4 at time t
After 16 hrs,= 15*60*60 second = 54000
[N2O5] = 0.543* exp(-54000* 1*10-5) =0.32 M
Moles of N2O5 reacted= (0.543-0.32)*1.44 =0.32 moles
From the reaction, moles of oxygen formed = 0.32/2= 0.16 moles
From PV= nRT, P= nRT/V= 0.16*0.0821*(45+273)/12.6 =0.3315 atm, partial pressure of oxygen