What is a solute of rainwater?

The solute of rainwater primarily consists of dissolved gases and minerals that the water collects as it falls through the atmosphere and interacts with surfaces. Common solutes include carbon dioxide, which forms carbonic acid, and various ions like sodium, chloride, calcium, and sulfate from dust and aerosols. Additionally, pollutants such as nitrates and phosphates can also be present, depending on environmental factors. Overall, these solutes contribute to the natural acidity and mineral content of rainwater.