To determine which of the given substances is an acid, we need to understand the definitions and properties of acids and bases.
1. LiOH (Lithium hydroxide): This compound contains a hydroxide (OH⁻) ion and is classified as a base, not an acid.
2. KOH (Potassium hydroxide): Similar to LiOH, this compound also contains a hydroxide (OH⁻) ion, indicating that it is a base.
3. [tex]\( NH_3 \)[/tex] (Ammonia): Ammonia is a compound that typically acts as a base. It does not donate protons (H⁺) but instead tends to accept them, forming [tex]\( NH_4^+ \)[/tex].
4. [tex]\( H_2SO_4 \)[/tex] (Sulfuric acid): This compound is well-known as a strong acid. It can donate two protons (H⁺) in a solution, making it a diprotic acid.
Given the properties of these substances, the one that fits the criteria of being an acid is [tex]\( H_2SO_4 \)[/tex] (Sulfuric acid).
Therefore, the correct answer is:
D. [tex]\( H_2SO_4 \)[/tex] (Sulfuric acid)
