Question

questions 3,4,5

TICLE complete the following sentence. The vapor A) spontaneous at low temperature and nonspontane B) nonspontaneous at all temperatures honspontaneous at low temperature and spontaneous at high temperature D) spontaneous at all temperatures E) not enough information given to draw a conclusion 3) Given the following reaction at equilibrium, if Kp = 1.20 at 250.0°C, KC PC13 (8) + Cl2 (g) PCI (8) A) 429 B) 2.79 x 10-2 51.5 D) 1.20 E) 3.90 x 10-6 4) All of the following statements about steel are true except A) it is a monomer B) it can be made so it resists rust C) it is an alloy of iron D) it can have different percentages of carbon E) none of the above 5) ) What is the mole fraction of NH3 in a solution prepared by dissolving 12.0 g of NH3 in 250.0 g of water? The density of the resulting solution is 0.974 g/mL. A) 0.0484 B) 0.940 C) 0.0480 D) 16.8 E) 0.922 B-1

Answer 1

3. We have the relation: K_p = K_c * (RT)ⁿ , where R is ags constant, T is temperature in K and n is change in gaseous moles

Kc = 1.20 / (0.0821 * 523)¹ = 2.79 * 10^-2 M

4. E) non eof the above

5. Moles of NH₃ = mass / molar mass = 12 / 17 = 0.706 mol

Moles of water = mass / molar mass = 250 / 18 = 13.889 mol

Mole fraction of NH₃ = Moles of NH₃ / total moles = 0.706 / (0.706 + 13.889) = 0.0480