Question

At 74.0 °C, what is the maximum value of the reaction

quotient, Q, needed to produce a non-negative E value for the
reaction SO4 (aq) + 4H+ (aq) + 2Br (aq) = Br2 (aq) + SO2(g) +
2H₂O(1) In other wo

Answer 1

The student seeks to understand how to calculate the equilibrium concentrations of H₂ and HBr in a reaction involving these species and Br₂ given the equilibrium constant and the concentration of Br₂ at equilibrium.

Step-by-step explanation:

The student's question pertains to the concept of reaction quotients (Q) and equilibrium constants (Keq) in chemical reactions, specifically oxidation-reduction reactions.

The value of Q provides information on the direction in which a reaction will proceed to reach equilibrium. Given the equilibrium constant for the reaction involving H₂, Br₂, and HBr, we can use the concentration of Br₂ at equilibrium to determine the concentrations of the other species.

To find the concentration of HBr at equilibrium, we apply the equation

Keq = [HBr]² / [Br₂][H₂].

As described, we know Keq and the concentration of Br₂, so we can solve for the concentration of HBr and subsequently, using the stoichiometry of the reaction, determine the concentration of H₂.