Four monoprotic weak acids are listed below at 25 °C
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Four monoprotic weak acids are listed below at 25 °C.
• Acid W: Ka=3.5×10−6
• Acid X: Ka=1.2×10−4
• Acid Y: Ka=7.9×10−8
• Acid Z: Ka=4.6×10−5
All solutions discussed are prepared at a concentration of 0.10 M. Assume activity coefficients are unity.
(a) Rank the four acids from strongest to weakest. Clearly indicate any ties.
(b) Write the formula of the conjugate base of each acid and rank the conjugate bases from strongest to weakest.
(c) For Acid X and Acid Y, compare the relative magnitudes of [HA] and [A−] at equilibrium in their 0.10 M solutions, and explain how the numerical values of the equilibrium constants support your comparison.