Ammonia is among the top ten synthesized compounds. Its many uses include the manufacture of ammonium nitrate and other fertilizers. Ammonia decomposes at high temperatures. In an experiment to explore this behavior, 2.00 moles of gaseous NH3 are sealed in a rigid 1-liter vessel. The vessel is heated at 800 K and some of the NH3 decomposes in the following reaction: 2 NH3 (g) <-> N2 (g) + 3 H2 (g)The system eventualky reaches equilibrium and is found to contain 1.740 mole of NH3. What are the values of Kp and Kc for the decomposition reaction at 800k?

Kc = 2.55x10⁻³

Kp = 10.97

Explanation:

Based on the reaction:

2 NH₃(g) ⇄ N₂(g) + 3H₂(g)

2 moles of ammonia produce 1 mole of nitrogen and 3 of hydrogen.

Kc is defined as:

Kc = [N₂] [H₂]³ / [NH₃]²

When 2.00 moles of NH₃ are added in a vessel and the reaction occurs, when the reaction is in equilibrium the moles of each specie is:

NH₃: 2.00moles - 2X

N₂: X

H₂: 3X

Where X represents reaction coordinate.

As moles in equilibrium of NH₃ are 1.740moles:

1.740 mol = 2.00 - 2X

0.13moles = X

That means moles of N₂ are 0.13 and H₂ 0.39

Replacing in Kc formula:

Kc = [0.13] [0.39]³ / [1.74]²

To obtain Kp from Kc you need to use the formula:

Kp = Kc (RT)^Δn

Where R is 0.082atmL/molK, T is temperature in Kelvin (800K) and Δn is change in moles of gas, that is moles of products - moles of reactants ( 4 - 2 = 2)

Replacing:

Kp = 2.55x10⁻³(0.082atmL/molKₓ800K)²7

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.