The surface tension of distilled water varies depending on its purity and temperature; however, based on the provided reference, the surface tension values for distilled water with some impurities ranged between 59.48 dyn/cm and 60.16 dyn/cm at a given temperature.
While the reference doesn't provide a definitive value for the surface tension of perfectly pure distilled water at a standard temperature like 20°C or 25°C, it implies that the accepted value for pure water at 100°C should be increased by around 2.5% based on these measurements. The reference focuses on water at a higher temperature but suggests that using a value of roughly 60 dyn/cm is a reasonable estimate at lower temperatures for real-world samples of distilled water.
Here’s a breakdown of how surface tension is affected by temperature, according to common scientific knowledge:
- Temperature and Surface Tension:
- Surface tension typically decreases as temperature increases. Molecules move more vigorously at higher temperatures, reducing the intermolecular forces at the surface that create surface tension.
- Standard Measurement Temperatures:
- Surface tension of water is often measured at 20°C or 25°C.
- The reference indicates results at different temperatures, and it's important to note that using values from different temperatures might cause a discrepancy.
- Impurities and Surface Tension:
- Impurities in water can affect surface tension. As demonstrated in the text, small amounts of impurities decreased the surface tension in the samples compared to the expected value of pure water.
Given this information, we can infer that the surface tension of perfectly pure distilled water at room temperature (20-25 °C) is typically cited as around 72 dyn/cm, while the imperfect samples of distilled water used in the reference yielded surface tension measurements between 59.48 dyn/cm and 60.16 dyn/cm. These values show that even small impurities in water can reduce its surface tension.
| Water Sample | Surface Tension (dyn/cm) |
|---|---|
| Distilled (Impure) | 59.48 - 60.16 |
| Pure Water (approx. at Room Temperature) | ~72 |
It's important to note that surface tension varies with temperature, and the reference mainly addresses surface tension at higher temperatures while noting that accepted values at 100 °C should be increased by ~2.5%.
