Hydrogen bromide decomposes when heated to 437C according to the equation: 2HBr(g) H2(g) Br2(g). If the reaction starts with 2.15 mol of hydrogen bromide in 1.0 liter, and decomposes to 36.7%, what is the equilibrium constant of the decomposition of hydrogen bromide

Explanation:

Amount of HBr dissociated

                                  2HBr(g)        ⇆          H2(g)           +          Br2(g)

Initial Changes          2.15                             0                                0  (mol)

                                - 0.789                      + 0.395                     + 0.395 (mol)

At equilibrium        1.361                            0.395                         0.395 (mole)

Concentration        1.361 / 1                   0.395 / 1                      0.395 / 1

at equilibrium (mole/L)

i'm assuming that the correct answer is indeed the first one/ "a"..

the ratio of the conjugate base to the acid required to attain the desired ph.