Answer: The equilibrium concentration of H2O(g) is 12.52 x [tex]10^{-3}[/tex]
Explanation: The given equilibrium reaction is -
[tex]C_{2}H_{4}(g) + H_{2}O(g) \rightleftharpoons C_{2}H_{5}OH(g)[/tex]
Equilibrium constant is the ratio of concentration of the products to the reactants.
Mathematically, it can be written as-
Kc = [tex][C_{2}H_{5}OH(g)][/tex] / [tex][C_{2}H_{4}][/tex] [tex] [H_{2}O][/tex]
Given values are -
Kc = 9.0 x [tex]10^{3}[/tex]
[tex][C_{2}H_{5}OH(g)][/tex] = 1.69M
[tex][C_{2}H_{4}][/tex] = 0.015M
Susbtituting these values in the equation we get
9.0 x [tex]10^{3}[/tex] = 1.69M / 0.015M [tex] [H_{2}O][/tex]
[tex] [H_{2}O][/tex] = 1.69M / 0.015M x 9.0 x [tex]10^{3}[/tex]
[tex] [H_{2}O][/tex] = 12.52 x [tex]10^{-3}[/tex]