The surface tension of water at room temperature around 20C or 68F is approximately 72.8 millinewtons per meter mN/m .The capillary rise method is a common technique used to measure surface tension. It is based on the principle that a liquid will rise or fall in a small diameter tube capillary due to the balance between the surface tension force and the gravitational force acting on the liquid. The method involves the following steps:1. Choose a clean, uniform capillary tube with a known inner diameter d . The diameter should be small enough to allow a significant rise of the liquid in the tube.2. Immerse the capillary tube vertically into the liquid water in this case and allow the liquid to rise or fall until it reaches equilibrium.3. Measure the height h of the liquid column in the capillary tube above or below the liquid's initial level.4. Determine the density of the liquid at the given temperature. For water at room temperature, the density is approximately 1000 kg/m.5. Measure the acceleration due to gravity g at your location. On Earth, it is approximately 9.81 m/s.6. Apply the Jurin's Law formula to calculate the surface tension of the liquid: = g h d/2 / cos where is the contact angle between the liquid and the capillary tube. For water and a clean glass tube, the contact angle is close to 0, so the cosine of the angle is approximately 1.7. Plug in the measured values for the height h , diameter d , density , and acceleration due to gravity g into the formula and calculate the surface tension .By following these steps and using accurate measurements, you can determine the surface tension of water at room temperature using the capillary rise method.