Question

Conjugate base for Brönsted acids \(H_2O\) and \( HF\) are

• A. \(OH^-\) and \(H_2F{+}\), respectively
• B. \(H_3O^+\) and \(F^-\), respectively
• C. \(OH^-\) and \(F^-\), respectively
• D. \(H_3O^+\) and \(H_2F^+\), respectively

Answer 1

The Correct Option is C

To determine the conjugate bases for the Brønsted acids \(H_2O\) and \(HF\), we first need to understand the concept of Brønsted-Lowry acid-base theory.

Brønsted Acids and Bases: According to the Brønsted-Lowry theory, an acid is a species that donates a proton (H⁺ ion), and a base is a species that accepts a proton.

Formation of Conjugate Base: When an acid donates a proton, the species that remains is its conjugate base.

1. Conjugate Base of \(H_2O\):
   • Water (\(H_2O\)) acts as a Brønsted acid by donating a proton to form \(OH^-\).
   • The reaction can be shown as:
     \( H_2O \to H^+ + OH^- \)
   • Thus, the conjugate base of \(H_2O\) is \(OH^-\).
2. Conjugate Base of \(HF\):
   • Hydrofluoric acid (\(HF\)) donates a proton to form \(F^-\).
   • The reaction can be shown as:
     \( HF \to H^+ + F^- \)
   • Thus, the conjugate base of \(HF\) is \(F^-\).

Comparing these with the given options, we find that the correct option is \(OH^-\) and \(F^-\), respectively.