homework problem

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Jane Burgan 1C
Posts: 73
Joined: Fri Sep 28, 2018 12:15 am

homework problem

Postby Jane Burgan 1C » Sun Jan 13, 2019 4:13 pm

For 11.43 in the 6th edition, the question says:
Consider the reaction 2 NO(g) -- ∆ N2(g) + O2(g). If the initial partial pressure of NO(g) is 1.0 bar, and x is the equilibrium concentration of N2(g), what is the correct equilibrium relation?

Why can't the answer be k = x^2/(1.0-x)^2, why is it k=x^2/(1.0-2x)^2? Is it because in the ice box since there's two moles of NO per each mole of N2 and O2 the change in concentration is now -2x instead of -x?

Matthew Tran 1H
Posts: 165
Joined: Fri Sep 28, 2018 12:16 am

Re: homework problem

Postby Matthew Tran 1H » Sun Jan 13, 2019 4:55 pm

You have to remember to use mole ratios! Since the change in N2 is x, then the change in NO is -2x because 2 NO's react to form 1 N2 and 1H2. You get this from the balanced chemical equation.

Andrew Bennecke
Posts: 62
Joined: Fri Sep 28, 2018 12:15 am

Re: homework problem

Postby Andrew Bennecke » Sun Jan 13, 2019 7:03 pm

In the reaction, we lose 2 moles of NO for every 1 mole of N2 and 1 mole of H2 produced. In the ICE box, the Change in Partial Pressure row would be -2x,+x,and +x. The Equilibrium of Partial Pressure row will be (1.0-2x), x, and x.

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