Why is distilled water preferred over tap water in practical chemistry?

Distilled water is preferred in practical chemistry primarily because it contains fewer impurities compared to tap water. When water is distilled, it undergoes a process of boiling and condensation that removes most salts, minerals, organic compounds, and other contaminants. This high level of purity is crucial in laboratory settings where the presence of impurities could interfere with experiments, alter reactions, or lead to inconsistent results.

For many chemical analyses and reactions, the introduction of foreign substances can significantly affect the outcome. Using distilled water helps ensure that experimental conditions remain controlled and replicable, which is a fundamental aspect of scientific inquiry.

In contrast, tap water may contain chlorine, minerals like calcium and magnesium, and other organic or inorganic compounds that could impact chemical reactions. Therefore, the attribute of having fewer impurities solidifies distilled water's status as the preferred choice for accuracy and reliability in chemistry.