## 11.7 Part C

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rileygilbertson
Posts: 17
Joined: Mon Oct 02, 2017 7:18 am

### 11.7 Part C

I don't understand where the equation (((Mole fraction of Px)Pi)^2)/(Mole Fraction of Px2)pi came from. After reading the section, I couldn't find this either. how did they derive it, or is it just common sense and I'm missing something?

Katie Lam 1B
Posts: 52
Joined: Fri Sep 29, 2017 7:06 am

### Re: 11.7 Part C

They only gave the overall pressure of the flask so in order to determine the partial pressures of X2 and X, you need to figure out the percentage of the total pressure for X2 and X. This is done by counting the number of molecules of X2 and X. Out of the 17 molecules in the flask, 12 were X and 5 were X2 so you use those fractions (12/17 and 5/17) and multiply them by the total pressure to get the partial pressures.

Rana YT 2L
Posts: 49
Joined: Thu Jul 27, 2017 3:01 am

### Re: 11.7 Part C

they use that equation because in order to determine partial pressures, you need to look at the number of moles of each gas atom or molecule within the closed volume since the number of moles of gas will determine how the reaction changes as it approaches equilibrium or how the reaction will react if there is a change to the system when it's originally at equilibrium