Given the Kc value for the following reaction at a particular temperature:                         SO2 (g) + ½ O2 (g) ⇋ SO3 (g)                  Kc = 4.45 What is the value of Kc for the new equilibrium below at the same temperature?                         2 SO3 (g) ⇋ 2 SO2 (g) + O2 (g)

Consider the voltaic cell diagram:  Sn(s) | Sn2⁺(aq) || Ag⁺ (aq) | Ag (s) What is the standard cell potential, E°cell, (in V) for this voltaic cell? Hint: Refer to the table of standard reduction potentials provided. Half Reaction E° red (V) Ag+ (aq)  + e–  →  Ag (s)  +0.80 Fe3+ (aq)  +   e–  → Fe2+ (aq)   +0.77 Cu2+ (aq)  + 2 e–  → Cu (s)    +0.34 Sn4+ (aq) + 2 e–  → Sn2+ (aq)   +0.15 2H+ (aq) + 2 e–  →  H2 (g)  0.00 Pb2+ (aq) + 2 e –  → Pb (s)  –0.13 Sn2+ (aq)  +  2 e–  → Sn (s)  –0.14 Ni2+ (aq) + 2 e –  → Ni (s)   –0.28 Cd2+ (aq) + 2 e –  → Cd (s)   –0.40 Fe2+ (aq) + 2 e –  → Fe (s) –0.44 Cr3+ (aq) + 3 e– →  Cr (s)      –0.74 Zn2+ (aq) + 2 e –  → Zn (s)  –0.76 Al3+ (aq) + 3 e– →  Al (s) –1.66  

Consider the following aqueous reaction between ammonia (NH3) and formic acid (HCOOH): NH3 (aq)  +  HCOOH (aq)   ⇌  NH4+ (aq)  + HCOO─ (aq) Identify the stronger acid and predict whether the equilibrium lies to the left or to the right? Hint: The Ka of HCOOH is 1.8 x 10─4 Hint: The Ka of NH4+ is 5.5 x 10─10

Consider the reaction: A ⇋ B The equilibrium constant for this reaction is Kc = 1.0. Which of the following diagrams best represents this reaction at equilibrium? Hint:  grey spheres = A      green spheres = B

The element oxygen was prepared by Joseph Priestly in 1774 by heating mercury (II) oxide:  2 HgO (g) ⟶ 2 Hg (s)   +    O2(g)   For this reaction, ΔH° = 90.84 kJ/mol and ΔS° = 108.23 J/(mol∙K). True or False.  This reaction is spontaneous at 373°C.

Which of the following solutions will have the highest pH? Hint: This is not a calculation problem. Consider the type of acid and base (strong vs. weak acid and base).  

For the following equilibrium CH4(g)  +   2 H2S(g)   ⇌   CS2(g)   +    4 H2(g) the equilibrium constant, K = 4.28 x 10−34 at 280.0 °C. Which of the following best describes the reaction at equilibrium?

Methane gas can be produced by the reaction of solid carbon with hydrogen gas as follows                     C(s)   +   2 H2(g)  ⇌   CH4(g)         Kp =  0.50 A vessel containing carbon is sealed and injected initially with hydrogen to a partial pressure of 2.0 atm and with methane to a partial pressure of 2.0 atm. Is the reaction at equilibrium? If not, which way will the reaction proceed to reach equilibrium?

Phophorous-32 decays by beta emission to form sulfur-32.   (In case the picture does not show: The picture indicated that 24 P-32 decayed to 3 P-32 in 9min. )  What is the decay constant, k, for P-32?

What is the molar solubility (in M) of cadmium hydroxide, Cd(OH)2, in water? Hint:  Ksp of Cd(OH)₂ is 2.0 × 10-14