1) In the reaction NaOH + H2O --> Na+ + OH-, sodium hydroxide is the:
A) Lewis acid
B) Brønsted-Lowry acid
C) Arrhenius base
D) Amphoteric substance
E) None of the above
(I think it's C)
2) The conjugate acid of the sulfide ion is:
A) S^2-
B) HS-
C) H2S
D) H3S+
E) None of the above
(I think it's C)
I think 1 is right and 2 is wrong.
The conjugate acid of S= is HS^-. The conjugate acid of HS^- is H2S.
I see my mistake now, thanks!
To determine the correct answers for these questions, we need to understand the definitions of Lewis acids, Brønsted-Lowry acids, Arrhenius bases, and conjugate acids.
1) Lewis acids are substances that can accept a pair of electrons to form a covalent bond. Brønsted-Lowry acids are substances that donate protons (H+ ions). Arrhenius bases are substances that produce hydroxide ions (OH-) in water. An amphoteric substance is one that can act as both an acid and a base, depending on the reaction conditions.
In the given reaction, NaOH + H2O --> Na+ + OH-, sodium hydroxide (NaOH) is dissociating in water to produce sodium ions (Na+) and hydroxide ions (OH-). Since NaOH is producing hydroxide ions, it fits the definition of an Arrhenius base. Therefore, the correct answer is C) Arrhenius base.
2) The sulfide ion (S^2-) has a negative charge and can act as a base by accepting a proton (H+). The conjugate acid of a base is formed by adding a proton (H+). In this case, the sulfide ion (S^2-) can accept a proton to form hydrogen sulfide (H2S) as its conjugate acid. Therefore, the correct answer is C) H2S.