Given the following equilibrium constants at \(427^{\circ} \mathrm{C}\) $$\begin{array}{ll}\mathrm{Na}_{2} \mathrm{O}(s) \rightleftharpoons 2 \mathrm{Na}(l)+\frac{1}{2} \mathrm{O}_{2}(g) & K_{1}=2 \times 10^{-25} \\\\\mathrm{NaO}(g) \rightleftharpoons \mathrm{Na}(l)+\frac{1}{2} \mathrm{O}_{2}(g) & K_{2}=2 \times 10^{-5} \\\\\mathrm{Na}_{2} \mathrm{O}_{2}(s) \rightleftharpoons 2 \mathrm{Na}(l)+\mathrm{O}_{2}(g) & K_{3}=5 \times 10^{-29} \\\\\mathrm{NaO}_{2}(s) \rightleftharpoons \mathrm{Na}(l)+\mathrm{O}_{2}(g) & K_{4}=3 \times 10^{-14}\end{array}$$,determine the values for the equilibrium constants for the following reactions: a. \(\mathrm{Na}_{2} \mathrm{O}(s)+\frac{1}{2} \mathrm{O}_{2}(g) \rightleftharpoons \mathrm{Na}_{2} \mathrm{O}_{2}(s)\) b. \(\mathrm{NaO}(g)+\mathrm{Na}_{2} \mathrm{O}(s) \rightleftharpoons \mathrm{Na}_{2} \mathrm{O}_{2}(s)+\mathrm{Na}(l)\) c. \(2 \mathrm{NaO}(g) \rightleftharpoons \mathrm{Na}_{2} \mathrm{O}_{2}(s)\) (Hint: When reaction equations are added, the equilibrium expressions are multiplied.)

Short Answer

Expert verified
The equilibrium constants for the new reactions are: a. \(Ka = 2.5 \times 10^{-4}\) b. \(Kb = 4 \times 10^{-30}\) c. \(Kc = 1.6 \times 10^{-9}\)

Step by step solution

01

Identify the given reactions and their equilibrium constants

We are given the following reactions with their respective equilibrium constants: 1. Na2O(s) <=> 2Na(l) + 0.5O2(g) with K1 = 2 x 10^-25 2. NaO(g) <=> Na(l) + 0.5O2(g) with K2 = 2 x 10^-5 3. Na2O2(s) <=> 2Na(l) + O2(g) with K3 = 5 x 10^-29 4. NaO2(s) <=> Na(l) + O2(g) with K4 = 3 x 10^-14
02

Manipulate the given reactions to obtain the desired reactions

We need to obtain the new reactions: a. Na2O(s) + 0.5O2(g) <=> Na2O2(s) b. NaO(g) + Na2O(s) <=> Na2O2(s) + Na(l) c. 2NaO(g) <=> Na2O2(s) Now, let's manipulate the given reactions: For (a), subtract Reaction 1 from Reaction 3: Na2O2(s) + 2Na(l) + O2(g) - (Na2O(s) + 2Na(l) + 0.5O2(g)) = Na2O(s) + 0.5O2(g) <=> Na2O2(s) For (b) add Reaction 1 and Reaction 2: Na2O(s) + 2Na(l) + 0.5O2(g) + NaO(g) <=> Na(l) + 0.5O2(g) + Na2O2(s) + Na(l) For (c), double Reaction 2 and subtract Reaction 3: (2)(NaO(g) <=> Na(l) + 0.5O2(g)) - (Na2O2(s) <=> 2Na(l) + O2(g)) = 2NaO(g) <=> Na2O2(s)
03

Apply rules for combining equilibrium constants

For (a), when we subtract equilibrium expressions (Reaction 3 - Reaction 1), we divide the equilibrium constants (K3 / K1): Ka = K3 / K1 = (5 x 10^-29) / (2 x 10^-25) = 2.5 x 10^-4 For (b), when we add equilibrium expressions (Reaction 1 + Reaction 2), we multiply the equilibrium constants (K1 * K2): Kb = K1 * K2 = (2 x 10^-25) * (2 x 10^-5) = 4 x 10^-30 For (c), when we double Reaction 2 and subtract Reaction 3, first we square the equilibrium constant of Reaction 2 (K2^2) and then divide it by the equilibrium constant of Reaction 3 (K2^2 / K3): Kc = (K2^2) / K3 = (2 x 10^-5)^2 / (5 x 10^-29) = 1.6 x 10^-9 So, the equilibrium constants for the new reactions are: a. Ka = 2.5 x 10^-4 b. Kb = 4 x 10^-30 c. Kc = 1.6 x 10^-9

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Most popular questions from this chapter

"Old-fashioned "smelling salts" consist of ammonium carbon=ate, \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3} .\) The reaction for the decomposition of ammomium carbonate $$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}(s) \rightleftharpoons 2 \mathrm{NH}_{3}(g)+\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)$$,is endothermic. Would the smell of ammonia increase or decrease as the temperature is increased?

For a typical equilibrium problem, the value of \(K\) and the initial reaction conditions are given for a specific reaction, and you are asked to calculate the equilibrium concentrations. Many of these calculations involve solving a quadratic or cubic equation. What can you do to avoid solving a quadratic or cubic equation and still come up with reasonable equilibrium concentrations?

A sample of solid ammonium chloride was placed in an evacuated container and then heated so that it decomposed to ammonia gas and hydrogen chloride gas. After heating, the total pressure in the container was found to be 4.4 atm. Calculate \(K_{\mathrm{p}}\) at this temperature for the decomposition reaction $$\mathrm{NH}_{4} \mathrm{Cl}(s) \rightleftharpoons \mathrm{NH}_{3}(g)+\mathrm{HCl}(g)$$,

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