Which of the following is most acidic :–A HNO3 B H2CO3 C H3BO3 D None of these

The acidity of a substance is determined by its ability to donate a proton (H+ ion). The more readily a substance donates a proton, the more acidic it is.

1. HNO3 (Nitric acid) is a strong acid, which means it completely ionizes in water and donates a proton very readily.

2. H2CO3 (Carbonic acid) is a weak acid, which means it does not ionize completely in water and does not donate a proton as readily as a strong acid.

3. H3BO3 (Boric acid) is a weak acid, even weaker than carbonic acid.

Therefore, out of the given options, HNO3 (Nitric acid) is the most acidic. So, the answer is A. HNO3.

The acidity of a substance is determined by its ability to donate a proton (H+ ion). The more readily a substance donates a proton, the more acidic it is.

1. HNO3 (Nitric acid) is a strong acid, which means it completely ionizes in water. It readily donates a proton, making it highly acidic.

2. H2CO3 (Carbonic acid) is a weak acid, which means it does not completely ionize in water. It does not donate protons as readily as HNO3.

3. H3BO3 (Boric acid) is a weak acid, even weaker than H2CO3. It does not donate protons as readily as HNO3 or H2CO3.

Therefore, out of the given options, HNO3 (Nitric acid) is the most acidic.