physical chemistry

The system N2O4 <--->2NO2 maintained in a closed vessel at 60º C & a pressure of 5 atm has an average (i.e. observed) molecular weight of 69, calculate Kp.
At what pressure at the same temperature would the observed molecular weight be (230/3)

  1. 👍 8
  2. 👎 1
  3. 👁 2,248
  1. I would do this.
    Let x = fraction of gas that is NO2
    The 1-x = fraction that is N2O4
    molar mass NO2 = 46
    molar mass N2O4 = 92

    46(x) + (92(1-x) = 69
    Solve for x and I get 0.5 which is the mole fraction of these gases.
    Then pNO2 = XNO2*Ptotal
    and pN2O4 = XN2O4*Ptotal

    Finally, Kp = p^2NO2/pN2O4
    I think Kp = 2.5 but you need to confirm that.

    Part 2 is similar.
    46(x) + 92(1-x) = 230/3 = 76.67
    x = about 0.333 = fraction NO2 = XNO2
    1-x = about 0.666 = XN2O4
    Then pNO2 = XNO2*Ptotal
    and pN2O4 = XN2O4*Ptotal

    Substitute pNO2 and pN2O4 into Kp and solve for Ptotal
    Kp = p^2NO2/pN2O4 = (0.333P)^2/(0.667P)
    and I solved for Ptotal as 1.5 atm. You should confirm that.

    1. 👍 15
    2. 👎 12
  2. I believe that is 15 atm for Ptotal and not 1.5.

    1. 👍 14
    2. 👎 4

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Consider the following chemical equation: 2NO2-->N2O4 If 25.0mL of NO2 gas is completely converted to N2O4 gas under the same conditions, what volume will the N2O4 occupy?

  2. Chemistry

    What is the process to calculate ΔH° for the reaction? O2(g) + 2NO(g) --> N2O4(g) O2(g) + 2NO(g) --> 2NO2(g) ΔH°1 N2O4(g) --> 2NO2(g) ΔH°2 a) ΔH°1 + ΔH°2 b) ΔH°1 - ΔH°2 c) ΔH°2 - ΔH°1 d) ΔH°1 - 2ΔH°2 I know

  3. chemistry

    For 2SO2(g)+O2(g)⇌2SO3(g), Kp=3.0×104 at 700 K. In a 2.00-L vessel the equilibrium mixture contains 1.15 g of SO3 and 0.107 g of O2. 1) How many grams of SO2 are in the vessel? ---------------------------- A flask is charged

  4. Chemistry

    How do i figure out if 2NO2 -> N2O4 is a redox reaction

  1. chemistry

    A 1.00 mol sample of N2O4 (g) is placed in a 10.0 L vessel and allowed to reach equilibrium accourding to the equation N2O4(g) 2NO2(g) K = .0004 Calculate the equilibrium concentrations of N2O4(g) and NO2(g)

  2. chemistry

    2NO2(g)⇌N2O4(g). ΔH∘f for N2O4(g) is 9.16 kJ/mol.

  3. Chemistry

    Consider the following chemical equation : 2NO2(g)=N2O4(g). If 25.0mL of NO2 gas is completely converted to N2O4 gas under the same conditions, what volume will the N2O4 occupy?

  4. Chemistry

    Dinitrogen tetroxide decomposes to nitrogen dioxide: N2O4(g)→2NO2(g)ΔHorxn=55.3kJ At 298 K, a reaction vessel initially contains 0.100 atm of N2O4. When equilibrium is reached, 58% of the N2O4 has decomposed to NO2. What

  1. AP Chemistry

    Calculate the standard entropy change for the dimerization of NO2: 2NO2(g)→N2O4(g)at 298 K, if S◦ ∆H◦f J/K·mol NO2(g) 240.06 33.18 N2O4(g) 304.29 9.16 Answer in units of J/K·mol

  2. chemistry

    Given Kc values: N2(g)+1/2 O2(g)N2O(g) Kc=2.7* 10^-18 N2O4(g)2NO2(g) Kc=4.6*10^-3 1/2N2(g)+O2(g)NO2(g) kc=4.1*10^-9 What is the Kc value for: 2N2O(g)+3O2(g)2N2O4(g)

  3. Chemistry

    Having some confusion with this question....I have the answers, just not able to reach them. A flask of volume 5L is evacuated and 43.8 g of solid N2O4 is introduced at 77K. The sample is then warmed to 298K during which the N2O4

  4. physics

    A closed inexpansible vessel contains air saturated with water vapour at 77 degree Celsius.The total pressure in the vessel is 1007mmHg.Calculate the new pressure if the temperature is reduced at 27 degree Celsius (S.V.P of water

You can view more similar questions or ask a new question.