1. If the surface tension of water is 72.8 mN/m, calculate the energy required to wing one molecule of water iro.1 the _ulx to the surface. The area of a wate. mo. ecure is about .1 nm . _. At room temperature 25 .C, a water drop of 4 mul radius is split up into 100 tiny c.ops. Find the increase in su.face energy. 3. Derive the equation for the capillary ise Letween parallel plates, including the correction team for meniscus weight. Assume zero contact angle, a cylindrical meniscus, and neglect end effects. 4. In a rotating drop measurement, what is the interfacial tension if the two liquids differ in density by 0.2 g/cm , the speed of rotation is -0 rpm, the volume of the drop is 0.4 cms, and the length of the extended drop is 6.5 cm? 5. The surface tension of a liquid is to be determined at 293 K employing the drop-weight method using water as the reference liquid The weight of 100 drops of water and the sample liquid were measured, and these values were 3.393 10-s kg and 1.876*10 kg, respectively. From these data, determine the surface tension of the sample liquid. Comment on the accuracy of the measurement. J. Calculate the pressures inside air bubbles having 1, 10 and 100 nm radii in water at 298 K and atmospheric pressure. Comment on your results. Given' saturated vapour pressure of water at 298 K is 3.1 / kva