** copy and paste error, Could someone walk me through this please! For the decomposition of phosphorous pentachloride to phosphorous trichloride and chlorine at 400K the KC is 1.1x10-2. Given that

asked by @jadec9 • about 1 year ago • Chemistry • 5 pts

1.0g of phosphorous pentachloride is added to a 250mL reaction flask, find the percent decomposition after the system has reached equilibrium.....the equation given is PCl5(g) <-->PCl3(g)+Cl2(g) Kc=1.1x10^2

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Hey Jadec9! I am going to start you off on this problem and have you finish it yourself. In the attached picture you will see how to properly do an ICE table for this problem. The question is asking to find % decomposition, that means your goal is to find how much was decomposed. You need to solve for x variable since that is how much is decomposed of PCl5. Because here when we divide initial concentration by Kc, we get a smaller than 500 number, that means we can not ignore the minus x on the denominator. You need to do a quadratic :( to solve for x.

Because you have two different Kc that you wrote in here, one is to the negative 2, the other to the positive, I'm not going to solve for x. Just make sure to use the correct Kc that the problem gives. When you solve for x, use the percent decomposition equation to calculate the final answer. You should be good from here. Let us know if you are not sure about something in my explanation.

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answered by @dashab2 • about 1 year ago