Question

which compound is not a base? a nh₃ b naoh c hclo₄ d nh₄oh

Explanation:

A base is a substance that can accept protons (H⁺ ions) or release hydroxide (OH⁻) ions in solution. NH₃ is a weak base that can accept a proton. NaOH and NH₄OH are bases that release OH⁻ ions. HClO₄ is a strong acid as it donates a proton (H⁺) in solution.

Answer:

C. HClO₄