Which of the following is a chemical property of H2O?

• A. H2O is colorless in its liquid state.
• B. H2O has a boiling point of 100°C at 1 atm.
• C. H2O reacts with sodium to produce hydrogen gas.
• D. H2O has a density of approximately 1 g/cm^3 at room temperature.

Answer: (C)

Verified step by step guidance

1. Understand the difference between physical and chemical properties: Physical properties can be observed or measured without changing the substance's identity, while chemical properties describe a substance's ability to undergo chemical changes and form new substances.
2. Examine each option to determine if it describes a physical or chemical property:
3. Option 1: 'H2O is colorless in its liquid state' describes a physical property because it relates to appearance without changing the substance.
4. Option 2: 'H2O has a boiling point of 100°C at 1 atm' is a physical property since boiling point is a physical characteristic.
5. Option 3: 'H2O reacts with sodium to produce hydrogen gas' describes a chemical property because it involves a chemical reaction and formation of new substances.
6. Option 4: 'H2O has a density of approximately 1 g/cm^3 at room temperature' is a physical property related to mass and volume.