Use the following acid ionization constants to identify the correct decreasing order of base strengths for the conjugate bases.
HF $\quad$ $\quad$ $\quad$ K_a = 7.2 $\times$ 10^-4
HNO₂ $\quad$ $\quad$ K_a = 4.5 $\times$ 10^-4
HCN $\quad$ $\quad$ K_a = 6.2 $\times$ 10^-10

Question

Use the following acid ionization constants to identify the correct decreasing order of base strengths for the conjugate bases.
HF

\quad

\quad

\quad

K_a = 7.2

\times

10^-4
HNO₂

\quad

\quad

K_a = 4.5

\times

10^-4
HCN

\quad

\quad

K_a = 6.2

\times

10^-10

Quizplus · Accepted Answer

In order to determine the decreasing order of base strengths for the conjugate bases of HF, HNO2, and HCN, we need to look at the respective acid ionization constants, specifically the K values for the conjugate bases. The higher the K value, the stronger the conjugate base.

Comparing the K values for the conjugate bases of HF (F-), HNO2 (NO2-), and HCN (CN-), we can see that the order from highest to lowest is: F- > NO2- > CN-. Therefore, the correct decreasing order of base strengths for the conjugate bases is CN- > NO2- > F-.

Looking at the choices given, we can see that only option A lists the conjugate bases in the correct decreasing order of base strength: CN-, NO2-, F-. Therefore, the answer is A.

Use the Following Acid Ionization Constants to Identify the Correct \quad

Use the Following Acid Ionization Constants to Identify the Correct $\quad$