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Postby Maria1E » Tue Nov 21, 2017 10:42 am

A reactor for the production of ammonia by the Haber process is found to be at equilibrium with P(N2) = 3.11 bar, P(H2) = 1.64 bar, and P(NH3) = 23.72 bar. If the partial pressure of N2 is increased by 1.57 bar, what will the partial pressure of each gas be once the equilibrium is reestablished?

I filled out a table and got the correct equation for the equilibrium constant. However, the solution manual says the equation can be solved using a graphing calculator. My question is, how would we go about solving this equation only using a scientific calculator?

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Re: 11.79

Postby Chem_Mod » Tue Nov 21, 2017 4:11 pm

Hi, Maria,
Cubic equations are usually solved in two ways: either by plotting a graph and finding intercepts or by trial and error, meaning that you try to approximate the number that x must take to get the overall value to be very close to 0. So, you can try any of these two ways to solve 11.79, however, you are not responsible for cubic equations as they are usually very difficult to solve. Also, there is a formula to solve cubic equation, however, it is extremely long and complicated, so there is no way to actually memorize it.

Jennie Fox 1D
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Re: 11.79

Postby Jennie Fox 1D » Tue Nov 21, 2017 5:23 pm

For this problem, we would need to use a graphing calculator in order to solve for "x". We shouldn't get a problem like this on a test unless we are allowed to use a graphing calculator.

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