Chem II

The equilibrium constant, Kp for the reaction PCl5 <---> PCl3 + Cl2 is 1.05 at 250 degrees C. The reaction is started with PCl5, PCL3 and Cl2 at 0.177, 0.223, and 0.111 atm at 250 degrees C. When the reaction comes to equilibrium, the pressure of _________

PCl3 must have decreased
Cl2 must have decreased
PCl5 must have decreased
PCl5 must have increased

I am not sure how to do this problem. I have tried subing 1.05 into the Kp formula and leaving one of the pressures out, but the answers that I would get when plugged back into the formula would not give 1.05 as an answer

  1. 👍 0
  2. 👎 1
  3. 👁 1,187
  1. This is about reaction quotient. Here is a site to give you some background.
    http://elchem.kaist.ac.kr/vt/chem-ed/courses/equil/intro/reactquo.htm

    Write the Kp expression.
    Kp = pPCl3 x pCl2/pPCl5 = 1.05
    Of course, substituting the values you won't get 1.05 but substitute anyway. Like this.
    Reaction quotient = Qp = (0.223)(0.111)/0.177 = about 0.14 if I punched my calculator correctly. So look at the value of Qp. It is LESS THAN Kp (which is 1.05). That means the numerator (products) is too small and the denominator (reactants) is too large. So you know the reaction will go to the right as it reaches equilibrium. That means PCl5 will decrease, PCl3 will increase, Cl2 will increase. Now you only need to pick out the correct answer from your choices.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    The equilibrium constant (Kp) for the interconversion of PCl5 and PCl3 is 0.0121: PCl5 (g) ↔ PCl3 (g) + Cl2 (g) A vessel is charged with PCl5, giving an initial pressure of 0.123 atm. At equilibrium, the partial pressure of PCl3

  2. chemistry

    What is the percent yield for the reaction PCl3(g) + Cl2(g) --> PCl5(g) if 119.3 g of PCl5 are formed when 61.3 g of Cl2 react with excess PCl3? I don't understand how to set this up?

  3. Chemistry

    You wish to know the enthalpy change for the formation of liquid PCl3 from the elements shown below. P4(s) + 6 Cl2(g)--> 4 PCl3(l) ΔH°f = ? The enthalpy change for the formation of PCl5 from the elements can be determined

  4. Chemistry

    Consider the following equilibrium: PCl3 (g) + Cl2 (g) yields PCl5 (g) delta H= -92KJ The concentration of PCl3 at equilibrium may be increased by: decreasing the temp (think this is it) adding Cl2 to the system the addition of

  1. Chemistry

    1.5 mole of PCl5 are heated at constant temperature in a closed vessel of 4 litres capacity.At the equilibrium,PCl5 is 35percent dissociated into PCl3 and Cl2.calculate the equilibrium constant.

  2. chemistry

    Phosphorus pentachloride decomposes according to the chemical equation PCl5(g) -----> PCl3 (g)+ Cl2(g) Kc= 1.80 at 250 degrees C A 0.463 mol sample of PCl5(g) is injected into an empty 4.80 L reaction vessel held at 250 °C.

  3. AP Chemistry

    2 Questions (Multi-choice and T/F, though not sure if they're right, and these 2 questions have no correspondence to each other) 1.) a.) Consider the following system at equilibrium where Kc = 1.20E-2 and H° = 87.9 kJ/mol at 500

  4. chemistry

    For the exothermic reaction PCl3(g)+Cl2(g)⇌PCl5(g) K = 0.160 at a certain temperature. A flask is charged with 0.507 bar PCl3 , 0.507 bar Cl2, and 0.304 bar PCl5 at this temperature. What are the equilibrium partial pressures of

  1. chem

    You are given the following data. P4(s) + 6 Cl2(g) 4 PCl3(g) H = -1225.6 kJ P4(s) + 5 O2(g) P4O10(s) H = -2967.3 kJ PCl3(g) + Cl2(g) PCl5(g) H = -84.2 kJ PCl3(g) + 1/2 O2(g) Cl3PO(g) H = -285.7 kJ Calculate H for the following

  2. Chemistry - Answer Check

    The two common chlorides of Phosphorus, PCl3 and PCl5, both important in the production of other phosphorous compounds, coexist in equilibrium as shown in the balanced chemical reaction below: PCl3 (g) + Cl2 (g) PCl5 (g) At 250 C,

  3. Chemistry

    PCl3 (s) + Cl2 (g) -> PCl5 (s) 1. WHAT VOLUME OF Cl2 would react with 1.4g of PCl3 to make PCl5? 2. IF YOU WANTED to make 10g of PCl5, what volume of Cl2 would you need? 3. WHAT IS THE MAXIMUM MASS of PCl5 that could be made from

  4. Chemistry

    Consider the reaction: PCl3(g) + Cl2(g) PCl5(g). If [PCl3] = 0.78 M, [Cl2] = 0.44 M, and [PCl5] = 0.88 at equilibrium, what is the value of K? A.0.39 B.1.4 C.2.6 D.0.72 Thanks!

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