Increase in temperature increases the kinetic energy of the molecules and effectiveness of intermolecular attraction decreases, so surface tension decreases as the temperature is raised.
Soap decreases the surface tension of water by weakening the hydrogen bonds.
Stalagmometer means a device used to measure the surface tension of a solution.
Intermolecular forces present in a liquid is a factor which affects its viscosity. Higher the intermolecular forces, higher will be the viscosity.