What is the correct chemical formula for carbonic acid?

• A. H2SO3
• B. H3PO4
• C. HCOOH
• D. H2CO3

Answer: (D)

Verified step by step guidance

1. Identify the components of carbonic acid: it is an acid formed from carbon dioxide and water, containing hydrogen (H), carbon (C), and oxygen (O).
2. Recall that carbonic acid is formed when carbon dioxide dissolves in water, producing H2CO3, which consists of 2 hydrogen atoms, 1 carbon atom, and 3 oxygen atoms.
3. Compare the given formulas to the known formula of carbonic acid: H2SO3 is sulfurous acid, H3PO4 is phosphoric acid, and HCOOH is formic acid.
4. Confirm that the formula H2CO3 matches the composition of carbonic acid, with the correct number of hydrogen, carbon, and oxygen atoms.
5. Conclude that the correct chemical formula for carbonic acid is H2CO3.