Complex ___ of ETC, which mediates transfer of electrons from succinate (FADH2) to UQ, is not a proton pump.

Complex II

Explanation:

Complex II does not directly pump protons but rather sends two protons on to Complex III in the form of the reduced UQ known as ubiquinol.

Thus, the correct answer is Complex II

[PCl₃] = 0.031M

[Cl₂] = 0.031M

[PCl₅] = 0.969M

Explanation:

Based on the reaction:

PCl₅(g) ⇄ PCl₃(g) + Cl₂(g)

Keq is defined as:

Keq = 1.0x10⁻³ = [PCl₃] [Cl₂] / [PCl₅]

Where [] are equilibrium concentrations of each species

Inital [PCl₅] = 2.0mol / 2.0L = 1M.

In equilibrium:

[PCl₃] = X

[Cl₂] = X

[PCl₅] = 1M-X

Where X is reaction coordinate

Solving for X in Keq:

1.0x10⁻³ = [X] [X] / [1-X]

1.0x10⁻³ - 1.0x10⁻³X = X²

1.0x10⁻³ - 1.0x10⁻³X - X² = 0

X:

X = -0.032M. False solution, there is no negative concentration

X = 0.031M

That means equlibrium concentrations are:

[PCl₃] = 0.031M

[Cl₂] = 0.031M

[PCl₅] = 1-0.031M = 0.969M