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Ch.15 - Chemical Equilibrium
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All textbooksMcMurry 8th EditionCh.15 - Chemical EquilibriumProblem 144

Chapter 15, Problem 144

Vinegar contains acetic acid, a weak acid that is partially dissociated in aqueous solution: CH3CO2H1aq2 ∆ H+ 1aq2 + CH3CO-1aq2 (b) What is the value of Kc if the extent of dissociation in 1.0 M CH3CO2H is 0.42%?

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Hello everyone today. We are being given the following problem. Hydrofluoric acid is a weak acid in solution, calculate the K. C. Value Or the equilibrium constant. If the% 1.5 molar Hydrofluoric acid is 2.21%. So first we need to draw an ice table. So we're gonna have our Hydrofluoric acid and a quick solution associate in a reversible reaction to protons or H. Plus and full ride ions. Of course we'll have our I. C. E. I. For initial concentrations C. For the change and E. For the total. So our initial concentrations for a Hydrofluoric acid was 1. molar. Of course we're not going to have any for our products and we are essentially dissociating this entire thing. So we're gonna say minus X. And then positive X. For both of our products. And so the total is going to be 1.5 molar minus R. X. Then we're just gonna have X. And X. For our products. That was our step one step 2. We're going to solve for the percent organization And then it's going to be our concentration of our fluoride divided by our concentration of our Hydrofluoric acid Time is 100%. Or we are solving for X. We have our personal organization which was 2. percent. Wriggling that two X. Which is the concentration of our fluoride divided by the concentration of Hydrofluoric acid which was 1.5 Moeller minus X. Times 100% In solving for X. We are going to get the X. is equal to 0.032. We're just gonna use equal the concentration of our fluoride, which is gonna equal our concentration of protons since they both represent X. And so lastly, we're going to solve for our equilibrium constant, which is going to be products divided by reactant, insofar products. We have our hydrogen concentration and we also have our fluoride and for our reactions, we just have our Hydrofluoric acid there. So since we said that these both represent X, our products, we can just take X and square it. So we have 0.32 Squared divided by are concentrated on Hydrofluoric acid, which is 1.5 -1, which would be 0.03, two. And we are going to get a final answer of 7.17 times 10 to the negative fourth. And with that we have solved the problem overall, I do hope this helped. And until next time.
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