Some_Basic_Concepts_of_Chemistry_Shobhit_Nirwan

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• Title: Shobhit Nirwan's Designed Some Basic Concepts of Chemistry

• Type: New Notes for Class 11, 2022 Exams

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• Overview of Chapter Topics:

  • Importance of Chemistry

  • Nature of Matter

    • Solid, Liquid, Gas

    • Mixtures

      • Homogeneous Mixtures

      • Heterogeneous Mixtures

    • Pure Substances

      • Elements

      • Compounds

  • Properties of Matter and Measurements

    • Physical Properties

    • Chemical Properties

    • SI Units: mass, volume, density, temperature

  • Uncertainty in Measurement

    • Scientific Notation

    • Operations with Significant Figures

    • Dimensional Analysis

  • Laws of Chemical Combination

    • Conservation of Mass

    • Definite Proportions

    • Multiple Proportions

    • Gay Lussac’s Law

    • Avogadro's Law

  • Dalton's Atomic Theory

  • Atomic & Molecular Masses

  • Mole Concept & Molar Masses

  • Percentage Composition

  • Stoichiometry and Calculations

  • Reactions in Solutions

    • Mass Percent

    • Mole Fraction

    • Molarity

    • Molality

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1. Importance of Chemistry:

   • Vital for weather patterns, brain function, and chemical industries (fertilizers, drugs).

   • Life-saving drugs: Cisplatin, Taxol for cancer; AZT for AIDS.

2. Nature of Matter:

   • Solids: Particles closely packed, definite shape and volume.

   • Liquids: Particles close but can move, definite volume, shape of container.

   • Gases: Particles far apart, easy movement, no definite volume or shape.

   • Mixtures: Combination of 2+ substances.

     • Homogeneous: uniform composition (e.g., air).

     • Heterogeneous: non-uniform composition (e.g., salt and sugar).

   • Pure Substances: Fixed composition, can be elements or compounds.

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3. Properties of Matter & Measurements:

   • Physical Properties: Measured without changing substance (e.g., color, density).

   • Chemical Properties: Changes identity (e.g., acidity, combustibility).

   • SI Units:

     • Mass: kg

     • Volume: m3 (commonly cm3 or dm3)

     • Temperature: K, °C, °F

     • Density: mass/volume

4. Uncertainty in Measurement:

   • Scientific Notation: Expressing numbers in powers of 10.

   • Operations (addition, multiplication) must consider significant figures.

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• Significant Figures: Determine based on reliability and uncertainty in measurement. Rules include:

  • Non-zero digits are significant.

  • Leading zeros are not significant.

  • Zeros between significant digits are significant.

  • Trailing zeros in decimal numbers are significant.

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6. Laws of Chemical Combination:

   • Conservation of Mass: Matter cannot be created or destroyed.

   • Definite Proportions: Fixed proportions by weight in compounds (Proust).

   • Multiple Proportions: Ratios of masses of elements in compounds are small whole numbers (Dalton).

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• Gay Lussac's Law: Gases react in simple ratios by volume.

• Avogadro's Law: Equal volumes of gases contain equal molecules (at same temperature and pressure).

• Dalton’s Atomic Theory: Atoms are indivisible; compounds form from fixed ratios.

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7. Atomic & Molecular Masses:

   • Atomic mass unit (amu) based on carbon-12 standard.

   • Average atomic masses and molecular mass calculations based on atomic contributions.

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8. Mole Concept & Molar Masses:

   • One mole equals 6.022 x 10²³ particles.

   • Molar mass: mass of one mole of a substance in grams.

9. Percentage Composition:

   • Mass % = (mass of element in compound / molar mass of compound) × 100.

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10. Empirical & Molecular Formulas:

• Empirical: simplified ratio of elements.

• Molecular: exact number of atoms in the molecule.

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11. Balancing Chemical Equations:

• Must follow conservation of mass with equal number of atoms on both sides.

• Example balancing with metals and non-metals reactions.

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12. Stoichiometry:

• Relationships between quantities of reactants and products in chemical reactions.

• Balanced equations describe mole relationships.

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Limiting Reagent:

• Reactant that is fully consumed and limits product formation.

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Reactions in Solutions:

• Mass Percent:

  • = (mass of solute / mass of solution) × 100.

• Mole Fraction: Ratio of moles of component to total moles.

• Molarity: Moles of solute in one liter of solution.

• Molality: Moles of solute per kg of solvent.