Question

Which of the following compounds has the highest evaporation rate and vapor pressure?

He, H2O, NH3, HF

Answer 1

Answer:

H2O has the highest evaporation rate and vapor pressure

Answer 2

Among the following compounds, H2O has the highest evaporation rate and vapour pressure.

• Higher electronegativity suggests elevated polarity in the molecule including such an atom. This further improves the intermolecular forces of temptation between the molecules which enhances the boiling point of the compound.
• Vapour pressure also relies on the pressure induced by the evaporation of liquids. Three mutual components that affect vapour press are surface area, intermolecular forces and temperature. The vapour pressure of a molecule fluctuates at various temperatures.
• Fluorine is more electronegative than Oxygen, so technically, HF should immerse in more hydrogen bonding than water. But the problem is different. Each HF molecule maintains three lone pairs of fluorine and one hydrogen. HF molecules on normal make two hydrogen bonds. Each H2O molecule maintains two lone pairs of oxygen. H2O molecules are thus eligible to form an average of four hydrogen bonds. Hence, water molecules carry a portion in more hydrogen bonding than Hydrofluoric acid. Water molecules form heavy molecules and it is very difficult to smash their bonds. To break all its bonds, a huge quantity of energy is expected.
• Thus, H2O has an elevated boiling point than HF.