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Some Basic Concept Of Chemistry - Coggle Diagram
Some Basic Concept Of Chemistry
Importance of Chemistry
In daily life:
Fertilisers, drugs, detergents, alloys.
In economy:
Contributes to industries & employment.
In environment:
Alternatives to CFCs, tackling greenhouse gases
In future:
New materials (superconductors, polymers, optical fibres).
Matter & Nature of Matter
Definition:
Anything that has mass and occupies space.
States
Solid
(definite shape & volume)
Liquid
(definite volume, no definite shape)
Gas
(no definite shape/volume)
Classification
Mixtures
(homogeneous, heterogeneous)
Pure Substances
(elements, compounds)
Properties of Matter & Measurement
Physical Properties
: Colour, odour, melting/boiling point, density.
Chemical Properties
: Reactivity, combustibility.
Measurement:
Length, mass, time, etc.
SI Units & Measurements
Seven Base Quantities
: m, kg, s, A, K, mol, cd.
Derived Quantities
: Volume, density, speed.
Prefixes
: milli, micro, nano, etc.
Uncertainty in Measurement
Significant Figures:
Rules for accuracy & precision.
Scientific Notation
: Expressing very large/small numbers.
Dimensional Analysis:
Unit conversions.
Laws of Chemical Combination
Law of Conservation of Mass
– Lavoisier.
Law of Definite Proportions
– Proust.
Law of Multiple Proportions
– Dalton.
Gay Lussac’s Law of Gaseous Volumes.
Avogadro’s Law
– Equal volumes of gases → equal molecules
Dalton’s Atomic Theory
Postulates
Atoms indivisible.
Atoms of same element identical.
Compounds = fixed ratios.
Atoms rearrange in reactions.
Atomic & Molecular Masses
Atomic Mass (u):
Based on C-12 standard.
Average Atomic Mass
: Weighted mean of isotopes.
Molecular Mass
: Sum of atomic masses.
Formula Mass
: For ionic compounds.
Mole Concept & Molar Masses
Mole
= 6.022x 10^23 entities
Molar Mass
= mass of 1 mole (g/mol).
Used in quantitative calculations.
Percentage Composition
Used to check purity & derive formulas.
% Mass of element
=( Mass of element / Molar mass of compound) x 100
Empirical & Molecular Formula
Empirical
= simplest ratio.
Molecular
= actual number of atoms.
Stoichiometry & Calculations
Yield
% Yield =
(Actual/Theoretical) × 100.
Actual yield =
obtained.
Theoretical yield
= expected
Limiting Reagent:
Determines the extent of reaction.
Relations between moles, mass, and volume.
Based on balanced equations.
BY YUVASSREE