Which substances are acids? Check all that apply.

1; AgOH

2; HF

3; NiOOH

4; NH4OH

5; HMnO4

6; Zn (OH) 2

Only HF and HMnO₄ are acids and all others are base.

When the given substances are put in water, they break apart to give H⁺ or OH⁻ ions. Only HF and HMnO₄ will give H⁺ ions and others will give OH⁻ ions. It is these ions which give a substance its acidic or basic nature. All the substances that give H⁺ ions are acidic in nature. The others that give OH⁻ ions are basic in nature.