Question

Diethyl ether, used as an anesthetic, is synthesized by heating ethanol with concentrated sulfuric acid. Write the equilibrium constant expression for Kc.

Answer 1

Answer:

THE EQUILIBRIUM CONSTANT EXPRESSION Kc = $\frac{[C2H5OH]}{[C2H5OC2H5]}$

Explanation:

The equilibrium constant, Kc is an expression given by the ratio of the concentrations of the products over the reactants. TN.B: the activities of pure solids and liquids are equal to 1.

Kc = $\frac{[products]^n}{[reactants]^n}$ where n= no of moles

Reaction equation:

2C2H5OH  $\frac{conc H2SO4, 140^o}{}$→ C2H5OC2H5

⇒ Kc = $\frac{[C2H5OC2H5] [H2)]}{[C2H5OH]^2}$ but [H20] = 1

∴ Kc = $\frac{[C2H5OH]}{[C2H5OC2H5]}$

Answer 2

Answer:

The expression for the Kc is as follows:

Kc = Kp/(RT)^Δn

Explanation:

To calculate the expression of Kc, we need to first find the constant Kp and establish the relationship between them. Kp describes the relationship between the concentrations of the products and the concentration of the reagents in the equilibrium in terms of the partial pressures. Having the balanced equation, we have:

2C2H5OH + H2SO4 = (C2H5)2O + H2SO4H2O

Taking a = C2H5OH, b = H2SO4, c = (C2H5) 2O, d = H2SO4H2O

Kp = ((Pc)^1)*(Pd) ^ 1))/((Pa)^2)*(Pb)^1))

Kp can be related to the equilibrium constant in terms of the concentration of moles, Kc, by means of the equation:

Kp = Kc(RT)^Δn

Clearing Kc:

Kc = Kp/(RT)^Δn

Where Δn is the difference in moles of the products minus the moles of the reagents.