Aquantity of an ideal gas is collected in a graduated tube over the mercury in a barometer type arrangement. the volume of gas at 20°c is 50ml and the level of mercury is 100mm above the outside of the mercury level. the atmospheric pressure is 750mm. the volume of gas at stp is

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.