Q1: With increase in temperature, the surface tension of water

ANS:B - decreases

With an increase in temperature, the surface tension of water generally decreases. This phenomenon occurs because as the temperature rises, the average kinetic energy of water molecules also increases. At higher temperatures, water molecules have greater thermal energy, which weakens the cohesive forces between them at the surface. As a result, the surface tension decreases. So, the correct option is: decreases.