## equilibrium concentration with gases

Hannah_1G
Posts: 100
Joined: Wed Sep 18, 2019 12:22 am

### equilibrium concentration with gases

If the reaction is homogeneous with gas phase but the question is in terms of concentration and gives the moles of the reactants and products, is pressure ignored?

vpena_1I
Posts: 109
Joined: Sat Aug 24, 2019 12:15 am

### Re: equilibrium concentration with gases

Yes, given moles of reactants and products, you will find molarity of each and use it to calculate Kc of the equation, not Kp. Only answer in Kp if the reactants and products are given in terms of bar or atm.

ELu 1J
Posts: 51
Joined: Thu Jul 25, 2019 12:16 am

### Re: equilibrium concentration with gases

Yes, because the context of the problem is moles, that is what leads you to calculate Kc instead of Kp even though all substances are in gas phase.

Posts: 113
Joined: Thu Jul 11, 2019 12:16 am

### Re: equilibrium concentration with gases

Yes, because what you’re given corresponds to solving for Kc.

cassidysong 1K
Posts: 100
Joined: Fri Aug 30, 2019 12:15 am

### Re: equilibrium concentration with gases

Yes. Pressure isn't involved in Kc

Ariel Davydov 1C
Posts: 110
Joined: Thu Jul 11, 2019 12:16 am
Been upvoted: 1 time

### Re: equilibrium concentration with gases

Yes, but if asked to solve for partial pressures or Kp, you can use the Ideal Gas Law (PV=nRT) to solve for individual partial pressures and plug them into the Kp expression to solve for Kp.

BCaballero_4F
Posts: 94
Joined: Wed Nov 14, 2018 12:22 am

### Re: equilibrium concentration with gases

Yes in this case you can ignore pressure

Eunice Nguyen 4I
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

### Re: equilibrium concentration with gases

If moles of the reactants and products are included in the problem, then you'll just assume that pressure is ignored. You'd know partial pressure if the unit given is atm.