Which statement correctly describes natural water?

Which statement correctly describes natural water?

• A. Dissolved gases are present in natural water
• B. Natural water contains no dissolved gases
• C. Natural water is pure H2O with no other components
• D. Dissolved solids are present but not gases

Answer: (A)

Natural water is not just pure H2O; it contains other things dissolved from the atmosphere, minerals, and organisms. Gases such as oxygen and carbon dioxide readily dissolve in water, and the amount that can dissolve depends on temperature and pressure. This dissolved gas content supports aquatic life and drives certain chemical equilibria (for example, CO2 forming carbonic acid in water). So the statement that dissolved gases are present in natural water accurately describes what you would expect to find.

Natural water is not just pure H2O; it contains other things dissolved from the atmosphere, minerals, and organisms. Gases such as oxygen and carbon dioxide readily dissolve in water, and the amount that can dissolve depends on temperature and pressure. This dissolved gas content supports aquatic life and drives certain chemical equilibria (for example, CO2 forming carbonic acid in water). So the statement that dissolved gases are present in natural water accurately describes what you would expect to find.