Given the hypothetical reaction 2 A (s) + ? B (g) ⇌ 3 C (g), Kp = 0.0105 and Kc = 0.45 at 250 degrees Celsius. What is the value of the coefficient of B? 

CH₄ (g) + 2 H₂S (g) ⇆ CS₂ (g) + 4 H₂ (g)

Methane (CH₄) reacts with hydrogen sulfide to yield hydrogen gas and carbon disulfide, a solvent used in the manufacturing rayon and cellophane. What is the value of K_c at 1000 K if the partial pressures in an equilibrium mixture at 1000 K are 0.20 atm methane, 0.15 atm hydrogen sulfide, 0.30 atm carbon disulfide and 0.10 atm hydrogen gas? 

CH₄ (g) + 2 H₂S (g) ⇌ 4 H₂ (g) + CS₂ (g)

Which of the following does not represent a heterogenous equilibrium?  

I) CH₄(g) + 2 O₂(g) ⇌ CO₂(g) + 2 H₂O(g)                  
II) CO₂(g) + C(s) ⇌ 2 CO(g)
III) 2 H₂O(l) ⇌ 2 H₂(g) + O₂(g)
IV) CH₃COOH(aq) + H₂O(l) ⇌ CH₃COO^–(aq) + H₃O⁺(aq)

The following diagrams represent a hypothetical reaction A ¡ B, with A represented by red spheres and B represented by blue spheres. The sequence from left to right represents the system as time passes. Does the system reach equilibrium? If so, in which diagram(s) is the system in equilibrium? [Sections 15.1 and 15.2]