Consider the reaction.
PCl$_5$(g) $
ightleftharpoons$ PCl$_3$(g) + Cl$_2$(g)
K$_c$ = 0.0420
The concentrations of the products at equilibrium are [PCl$_3$] = 0.140 M and [Cl$_2$] = 0.190 M. What is the concentration of the
reactant, PCl$_5$, at equilibrium?
[PCl$_5$] =
M