Concentration and Types of Solutions

Jun 28, 2024

Chemistry Solutions: Pollution and Concentration

Introduction

  • First video in a series of two
  • First video: Concentration of Solutions
  • Second video: Solubility
  • Lecture by: Roshni

Definition of Solutions

  • Homogeneous mixture of two or more components
  • Example: Solution of salt and water
    • Uniform composition of the solution
  • Non-homogeneous mixture
    • Example: Mixture of peanuts and chickpeas

Types of Solutions

  • Air: Uniform mixture of nitrogen, oxygen, etc.
  • Liquid Solutions: Tea, coffee, fruit juice, etc.
  • Gaseous Solutions: Air
  • Solid-solid Solutions: Alloys (e.g., bronze)

e.g., Salt+Water = Salt Solution

  • Water [Solvent], Salt [Solute]

Solutions in Different Situations

  • Liquid in Solid
    • Example: Dissolving sugar in water
  • Solid in Solid
    • Example: Alloys
  • Liquid in Liquid
    • Example: Alcohol dissolving in water
  • Gas in Gas
    • Example: Air
  • Liquid in Gas
    • Example: Chloroform and nitrogen
  • Solid in Gas
    • Example: Hydrides

Concentration of Solutions

  1. Mass Percentage
    • Mass of Solute / Mass of Solution × 100
    • Example: 10% glucose in water = 10 grams of glucose in 100 grams of solution
  2. Volume Percentage
    • Volume of Solute / Volume of Solution × 100
    • Common in medical and pharmaceutical industries
  3. Parts per Million (PPM)
    • (Number of parts of the solute / Number of parts of the solution) × 1000000
    • Example: Concentration of different gases in oxygen
  4. Mole Fraction
    • Number of moles of component / Total moles of solution
  5. Molarity (M)
    • Number of moles of solute / Volume of solution in liters
    • Example: 0.25M NaOH = 0.25 moles of NaOH in 1 liter of solution
  6. Molality (m)
    • Number of moles of solute / Mass of solvent in kilograms
    • Temperature independent

Comparison: Molarity vs Molality

  • Molarity is temperature dependent
  • Molality is temperature independent
  • Examples and problems on molarity and molality

Conclusion

  • Types of solutions, methods of concentration, and their examples
  • Various ways of quantitative measurement of solution concentration

Problem Solving

  • Problems based on different concentration methods
    • Based on mass percentage, volume percentage, mole fraction, etc.

Next Video

  • Solutions Part-2: Solubility