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What is the surface tension of water at room temperature and atmospheric pressure, and how can it be experimentally measured using the capillary rise method?

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The surface tension of water at room temperature  around 20-25C  and atmospheric pressure is approximately 72 mN/m  millinewtons per meter .The capillary rise method is a common technique used to experimentally measure the surface tension of a liquid. In this method, a small diameter tube  capillary  is immersed in the liquid, and the liquid rises in the tube due to the surface tension. The height of the liquid column in the tube is related to the surface tension of the liquid.Here's a step-by-step procedure for measuring surface tension using the capillary rise method:1. Choose a clean, uniform capillary tube with a small diameter  e.g., a few millimeters . The inner diameter of the tube should be known or measured accurately.2. Immerse the capillary tube vertically into the water, ensuring that the water is at room temperature and atmospheric pressure.3. Observe the rise of the water column in the capillary tube. The water will rise until the force due to surface tension is balanced by the weight of the liquid column.4. Measure the height  h  of the liquid column above the water's surface outside the tube.5. Determine the density    of the water at the given temperature. For water at room temperature, the density is approximately 1000 kg/m.6. Measure the acceleration due to gravity  g , which is approximately 9.81 m/s.7. Calculate the surface tension    using the Jurin's Law formula:    =  ghr  / 2   where r is the radius of the capillary tube.By following these steps and using the capillary rise method, you can experimentally measure the surface tension of water at room temperature and atmospheric pressure.
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