Question

Structure, pressure, temperature all have an effect on solubility. Discuss each of their effects. What is henry’s law? Why does henry law does not work for HCl? What do the terms hydrophobic and hydrophilic mean?

Short answer

Temperature and pressure has the direct effect on solubility for ionic solids.

The following factors have some effect on solubility-

The temperature has a direct effect on solubility for ionic solids, but solubility decreases as temperature increases in gases, Pressure affects a gas in a liquid not a solid in a liquid. Solubility increases with an increase in pressure. Structure as inverse effect on solubility. The greater difference in the structure lower is the solubility.

The henry law states that while the temperature is constant, the amount of gas dissolved in a liquid is directly proportional to the partial pressure of the gas above the liquid.

It is written as P= K_H . C

Where P is partial pressure, C denotes the concentration of dissolved gas, K_H is the henry constant.

It does not work for HCl(g) because HCl(g) dissociates into its ion H⁺and Cl^-.

Hydrophobic and hydrophilic are opposite terms. Hydrophobic means substances that are water fearing and do not mix with water whereas hydrophilic means water-loving and easily mixes with water.

Step-by-step solution

Step 1- Temperature affects solubility

Solubility increases with an increase in temperature as the particles of solid move faster which increases their chance to interact with solvent particles which results in the increasing rate at which a solution occurs.

Step 2- Pressure affect solubility

When pressure is applied to a gas that is above the solvent the gas will move into the solvent and occupy spaces between particles of the solvent. Example carbonates drink.

Step 3- Structure affects solubility.

Two molecules that have the same structure and same intermolecular forces will usually be soluble in each other. In general, it is the concept that polar solutes dissolve polar solvents.

Step 4- Henry’s law does not work for HCl.

HCl is a powerful acid that rapidly interacts with solvents and dissociates into its component ions.