The acidity constant,K_a,differs from the equilibrium constant,K_eq,for the dissociation of the same acid in water at the same temperature and concentration in what way? A)K_a can be determined experimentally with less accuracy than K_eq. B)The two terms are identical numerically. C)K_a is used for strong acids only; K_eq for weak acids. D)K_a is the reciprocal of K_eq. E)K_eq = K_a/[H₂O].

Question

Quizplus · Accepted Answer

The acidity constant (K_a) is the equilibrium constant for the dissociation of an acid in water, while the equilibrium constant (K_eq) is the equilibrium constant for the acid-base reaction between the acid and water. The two constants are related by the equation: K_a = K_eq/[H₂O] This equation shows that the acidity constant is always smaller than the equilibrium constant, and that the difference between the two constants depends on the concentration of hydronium ions in the solution. Therefore, choice E is the best choice. Choices A, B, and D are incorrect because they do not accurately describe the relationship between the two constants. Choice C is incorrect because both the acidity and equilibrium constants can be used to describe the dissociation of weak and strong acids in water.

The Acidity Constant,Ka,differs from the Equilibrium Constant,Keq,for the Dissociation of the Same

The Acidity Constant,K_a,differs from the Equilibrium Constant,K_eq,for the Dissociation of the Same