posted by Anonymous .
how would you begin this question?
An empty 15.0 L cylinder, .500 moles of gaseous PCl5 are added and allowed to reach equilibrium. The concentration of PCl3 is found to be .0220M. (Temp at 375K)
PCl3(g) + Cl2(g) --> PCl5(g)
i need to fine how many moles of PCl5 remain at equilibrium
That is pretty easy. You started with .5moles PCl5, and it made .022*15 moles of PCl3. So looking at the balanced equation, it took .022*15 moles of PCl5 to do this.
So subtract the amount used from the initial amount.
so is it .17 moles of PCl5 remaining?
.5 - (.022 * 15) = 0.17
so, same question, we have to find the value of k..is my work right?
the equilibrium conc. of PCl5 = .01133 M
PCl3 = .022 M
Cl2 = .022 M
K = [PCl5]/[PCl3][Cl2}
K = [.01133]/[.022][.022]
K = 23.4
The set up is correct. I didn't check the calc work.