At-14.4 °C the concentration equilibrium constant K, -9.3x10 for a certain reaction. Here are some facts about the reaction: . Some of the reactants are liquids and solids. •The constant pressure molar heat capacity C,- 1.63 J-mol ¹-K¹. . If the reaction is run at constant pressure, 52.0 kl/mol of heat are released. Using these facts, can you calculate K, at -31. "C? If you said yes, then enter your answer at right. Round it to 2 significant digits. If you said no, can you at least decide whether Kat -31. "C will be bigger or smaller than Kat-14.4 °C? O Yes. O No. 0 Yes, and K will be bigger. Yes, and K, will be smaller. No. X

For the reaction 2CH,(g) =C,H2(g) + 3H2(g) Ke = 0.155 at 1611 °C. What is K, for the reaction at this temperature? Express your answer numerically. • View Available Hint(s) ? Kp =

2

Ammonia (NH3) decomposes to form nitrogen gas and hydrogen gas with an enthalpy of 89.4kJ/mol. Aclosed container is charged with 6.0 atm ammonia and heated to 25.0°C. At equilibrium the pressure of H2 is3.60atm. a. Write the balanced reaction.

Nitric oxide reacts with chlorine to form NOCI. 2NO(g) + Cl2g) → 2NOCI(g) The equilibrium constant K at 298K is x 107. (R = 8.314 J/K • mol) Substance: NO(g) Cl2g) NOCIG) AH°F (k]/mol) at 298 K 90.29 51.71 S°U/K• mol) at 298 K 210.65 223.0 261.60

At -5.92 °C the pressure equilibrium constant K = 5.9 for a certain reaction. P Here are some facts about the reaction: • If the reaction is run at constant pressure, 127. kJ/mol of heat are released. • The constant pressure molar heat capacity C • The net change in moles of gases is -1. = 2.41 J mol -1. K¹. -1 р Yes. ☐ x10 Using these facts, can you calculate K at -27. °C? ○ No. If you said yes, then enter your answer at right. Round it to 2 significant digits. Р If you said no, can you at least decide whether K at -27. °C will be bigger or smaller than K, at −5.92 °C? П Yes, and K, will be р bigger. Yes, and K smaller. will be No. ☑

Consider the reaction: PbCl2(s) → Pb2*(aq) + 2 Cl (aq) AH° = 23.30 kJ/mol and AS° = -12.5 J/K-mol a) When solid PbCl2 is dissolved in water at 25°C, what are the concentrations of Pb2* and Cl at equilibrium? (Hint: Do your ICE chart and Law of Mass Action.) Concentration of Pb2+: mol/L and Concentration of Cl = mol/L (Do not use superscripts, subscripts, or carets. Write 1.2 x 10-3 as 1.2x10-3 or 1.2e-3.) b) At 25°C, This reaction is (reactant or product) favored. Justify your answer with the appropriate calculation on the separate sheet of paper. c) The Gibbs free energy at 25°C, when both the concentrations of the lead ion and chloride ion are 1.2 x 10-³M is kJ/mol. Show your calculations on the separate sheet of paper.

[Review Topics] [References] Use the References to access important values if needed for this question. Consider the following system at equilibrium where AH° = -111 kJ/mol, and K. = 0.159 , at 723 K. N2 (g) + 3 H, (g)=2 NH3 (g) When 0.21 moles of NH, (g) are added to the equilibrium system at constant temperature: The value of K The value of Qe K. The reaction must O run in the forward direction to restablish cquilibrium. O run in the reverse direction to restablish coquilibrium. O remain the same. It is already at cquilibrium. The concentration of H, will Submit Answer Retry Entire Group 1 more group attempt remaining

Consider the following equilibrium: N₂ (g) + 3H₂(g)2NH₂ (g) AG = -34. KJ 2 Now suppose a reaction vessel is filled with 3.70 atm of hydrogen (H₂) and 8.46 atm of ammonia (NH3) at 1099. °C. Answer the following questions about this system: rise Under these conditions, will the pressure of H ₂ tend to rise or fall? x10 fall Is it possible to reverse this tendency by adding N₂? x Ś ? In other words, if you said the pressure of H₂ will tend to rise, can that be changed to a tendency to fall by adding N₂? Similarly, if you said the yes no pressure of H₂ will tend to fall, can that be changed to a tendency to rise 2 by adding N₂? If you said the tendency can be reversed in the second question, calculate the minimum pressure of N₂ needed to reverse it. atm Round your answer to 2 significant digits. ● O

Consider the following system at equilibrium where K. = 34.5 and AH° = -198 kJ/mol at 1150 K. 2 So, (g) + 02 (g) =2 S03 (g) The production of S03 (g) is favored by: Indicate True (T) or False (F) for each of the following: ]1. decreasing the temperature. v 2. increasing the pressure (by changing the volume). | 3. decreasing the volume. 4. removing SO3 . 5. removing O2 -