Concentration of Solutions: Molarity, Molality, Normality

Concentration of Solutions

• Concentration refers to the amount of solute present in a given amount of solution.
• It can be expressed in various ways, including:
  • Molarity (M)
  • Molality (m)
  • Normality (N)
  • Percentage (%)
  • Parts per million (ppm)

Normality (N)

• Normality is the number of equivalents of solute per liter of solution.
• It is often used to express the concentration of acids and bases.
• Normality is related to molarity by the following equation:
  • N = n * M where n is the number of equivalents per mole of solute.

Percentage (%)

• Percentage concentration is the amount of solute present in a solution as a percentage of the total solution.
• It can be expressed as:
  • % (w/w) = (mass of solute / mass of solution) * 100
  • % (w/v) = (mass of solute / volume of solution) * 100

Molarity (M)

• Molarity is the number of moles of solute per liter of solution.
• It is defined as:
  • M = moles of solute / liters of solution

Molality (m)

• Molality is the number of moles of solute per kilogram of solvent.
• It is defined as:
  • m = moles of solute / kilograms of solvent

Henry's Law

• Henry's law states that the amount of a gas dissolved in a solution is directly proportional to the pressure of the gas above the solution.
• It is expressed mathematically as:
  • C = k * P where C is the concentration of the gas, k is the Henry's law constant, and P is the pressure of the gas.

Raoult's Law

• Raoult's law states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent.
• It is expressed mathematically as:
  • P = P° * X where P is the vapor pressure of the solution, P° is the vapor pressure of the pure solvent, and X is the mole fraction of the solvent.

Colligative Properties

• Colligative properties are properties of a solution that depend on the number of particles (molecules or ions) present, rather than their identity.
• Examples of colligative properties include:
  • Boiling point elevation
  • Freezing point depression
  • Osmotic pressure
  • Vapor pressure lowering

Concentration of Solutions

• Concentration is the amount of solute present in a given amount of solution.
• It can be expressed in various ways, including molarity, molality, normality, percentage, and parts per million.

Normality (N)

• Normality is the number of equivalents of solute per liter of solution.
• It is often used to express the concentration of acids and bases.
• Normality is related to molarity by the equation: N = n * M, where n is the number of equivalents per mole of solute.

Percentage (%)

• Percentage concentration is the amount of solute present in a solution as a percentage of the total solution.
• It can be expressed as % (w/w) = (mass of solute / mass of solution) * 100 or % (w/v) = (mass of solute / volume of solution) * 100.

Molarity (M)

• Molarity is the number of moles of solute per liter of solution.
• It is defined as: M = moles of solute / liters of solution.

Molality (m)

• Molality is the number of moles of solute per kilogram of solvent.
• It is defined as: m = moles of solute / kilograms of solvent.

Henry's Law

• Henry's law states that the amount of a gas dissolved in a solution is directly proportional to the pressure of the gas above the solution.
• It is expressed mathematically as: C = k * P, where C is the concentration of the gas, k is the Henry's law constant, and P is the pressure of the gas.

Raoult's Law

• Raoult's law states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent.
• It is expressed mathematically as: P = P° * X, where P is the vapor pressure of the solution, P° is the vapor pressure of the pure solvent, and X is the mole fraction of the solvent.

Colligative Properties

• Colligative properties are properties of a solution that depend on the number of particles (molecules or ions) present, rather than their identity.
• Examples of colligative properties include:
  • Boiling point elevation
  • Freezing point depression
  • Osmotic pressure
  • Vapor pressure lowering

Understand the different ways to express concentration of a solution, including molarity, molality, normality, percentage, and parts per million.