Question

H_2S+SO_4^2− ⇌ ______ ⇌ HS^− +HSO_4^−

Which of the above chemical species is the conjugate base according to the Brønsted-Lowry definition?

A. HS^−
B. H_2S
C. SO_4^2−
D. HSO_4^−

Answer 1

The conjugate base in the given reaction is HS−, option A, which is formed when H2S donates a proton.

Step-by-step explanation:

According to the Brønsted-Lowry definition of acids and bases, an acid is a substance that donates a proton (H+), and a base is a substance that accepts a proton. In the reaction H2S + SO42− ⇌, we can identify the conjugate base by looking at the species formed after a proton is donated. From the options given:

• A. HS− is the conjugate base of H2S.
• B. H2S is the original acid, not a conjugate base.
• C. SO42− is not directly involved in the proton transfer of the given reaction.
• D. HSO4− is a conjugate acid resulting from the donation of a proton by H2SO4.

Therefore, the correct answer is A: HS− is the conjugate base that forms when H2S loses a proton.