Chemical Forums

Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: sqe on March 12, 2014, 09:40:54 PM

Title: Kp Equilibrium constant
Post by: sqe on March 12, 2014, 09:40:54 PM

Hi I'm having trouble figuring out the Kp with the given density and total pressure of the system.

"A flask contains only NO₂ and is heated to 375°C and reacts in the following equation:

2NO₂ (gas) <-> 2NO (gas) + O₂ (gas)

At equilibrium, the density of the gas mixture is 0.735 g/L and total pressure is 0.890 atm. What is the Kp for the reaction at 375°C?"

The possible answers are:
A) 8.32 x 10^-6
B) 7.45 x 10^-5
C) 2.24 x 10^-5
D) 3.78 x 10^-4
E) 1.3 x 10^-4

Anyone able to direct me how I would be able to achieve a Kp value?

Thanks!

Title: Re: Kp Equilibrium constant
Post by: sjb on March 13, 2014, 02:45:34 AM

Quote from: sqe on March 12, 2014, 09:40:54 PM

Hi I'm having trouble figuring out the Kp with the given density and total pressure of the system.

"A flask contains only NO₂ and is heated to 375°C and reacts in the following equation:

2NO₂ (gas) <-> 2NO (gas) + O₂ (gas)

At equilibrium, the density of the gas mixture is 0.735 g/L and total pressure is 0.890 atm. What is the Kp for the reaction at 375°C?"

The possible answers are:
A) 8.32 x 10^-6
B) 7.45 x 10^-5
C) 2.24 x 10^-5
D) 3.78 x 10^-4
E) 1.3 x 10^-4

Anyone able to direct me how I would be able to achieve a Kp value?

Thanks!

What is the definition of density?

Title: Re: Kp Equilibrium constant
Post by: sqe on March 15, 2014, 02:51:33 PM

Are you asking what density means or is this a way to initialize how to solve the problem?

Title: Re: Kp Equilibrium constant
Post by: Borek on March 15, 2014, 08:42:52 PM

Treat the question as a hint. How does the density depend on the AVERAGE molar mass of the gas?