What is a solution?

A solution is a homogeneous mixture of two or more substances. The solvent is present in a larger amount and dissolves the solute.

What are the different types of solutions?

Based on Physical States:

What is concentration of a solution?

Concentration is the amount of solute present in a given amount of solvent or solution.

What are the different ways to express concentration?

What is solubility?

Solubility is the maximum amount of solute that can be dissolved in a given amount of solvent at a specific temperature and pressure.

What factors affect solubility?

• Nature of solute and solvent – "Like dissolves like" (Polar solutes dissolve in polar solvents).
• Temperature – Solubility of solids increases with temperature, while gases decrease.
• Pressure (For gases in liquids) – Henry’s Law states that solubility of a gas is directly proportional to the pressure above the solution.

What is Henry’s Law?

Henry’s Law states that at constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid.

What is the mathematical equation for Henry’s Law?

p=K_Hx

where:

• p = Partial pressure of the gas,
• x = Mole fraction of the gas in the solution,
• K_H = Henry’s law constant.

What are applications of Henry’s Law?

Used to increase CO₂ solubility in soft drinks by applying high pressure.

Scuba divers experience decompression sickness (bends) due to nitrogen gas bubbles forming in blood at low pressures.

What is Raoult’s Law?

Raoult’s Law states that the partial vapor pressure of a volatile component in a solution is directly proportional to its mole fraction in the solution.

What is the mathematical equation for Raoult’s Law?

For a component A in a solution:
where:

p_A = Partial vapor pressure of component A,

x_A = Mole fraction of A,

p_A0 = Vapor pressure of pure A.

How does Raoult’s Law relate to Henry’s Law?

Raoult’s Law is a special case of Henry’s Law when the proportionality constant (K_H) = vapor pressure of pure solvent.

What are colligative properties?

Colligative properties are properties of solutions that depend only on the number of solute particles, not their nature.

What are the four colligative properties?

What is the van’t Hoff factor (i)?

The van’t Hoff factor (i) accounts for dissociation or association of solutes in solutions.

What is the formula for van't Hoff factor?

What is the significance of van’t Hoff factor?

i > 1 for solutes that dissociate (e.g., NaCl → Na⁺ + Cl⁻, i = 2).

i < 1 for solutes that associate (e.g., Acetic acid dimerizes in benzene).

What is reverse osmosis?

Reverse osmosis (RO) is the process of forcing solvent molecules through a semi-permeable membrane by applying pressure greater than the osmotic pressure.

What are applications of reverse osmosis?

• Desalination of seawater to produce drinking water.
• Purification of water in households and industries.