What is the boiling point of water when the atmospheric pressure exerted on the water is 81 kpa ?

The boiling point of water at 81 kPa will be 298.17 K.

Explanation:

The boiling point of water is 373 K at atmospheric pressure. So, to calculate the boiling point at 81 kPa, we use the law given by Gay-Lussac.

Gay-Lussac Law states that pressure is directly proportional to the temperature when volume and moles remain constant.

Mathematically,

where,

= Initial pressure and temperature

= Final pressure and temperature

We are given:

Putting values in above equation, we get:

Hence, the boiling point of water at 81 kPa will be 298.17 K.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.