What property of pure water is indicative of its purity when tested?

Pure water is known for being tasteless, which is a fundamental characteristic that can indicate its purity. The absence of taste suggests that there are no dissolved substances or impurities present in the water. When water contains salts, minerals, or organic compounds, it can acquire a distinct taste, which is a clear indication of contamination or impurity. Therefore, the tasteless nature of pure water acts as a straightforward yet effective test of its purity.

In contrast, changing color can signify the presence of impurities or contaminants, which are not characteristic of pure water. Boiling at 90°C is also not a property of pure water, as pure water typically boils at 100°C at standard atmospheric pressure, and any deviation suggests the presence of impurities affecting its boiling point. While evaporation rates can vary due to temperature and environmental conditions, they do not specifically indicate purity, as other factors can also influence how quickly a liquid evaporates. Therefore, the tasteless property of pure water is a reliable indicator of its purity.