Chapter 1 Notes | Chemistry 1st Year

“Basic Concepts”

Index:

1. Atom
2. Relative Atomic Mass
3. Isotopes
4. Analysis of a Compound – Empirical And Molecular Formulas
5. Concept of Mole
6. Stoichiometry
7. Limiting Reaction
8. Yield

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Key Points:

1. Atoms are the building blocks of matter. Atoms can combine to form molecules. Covalent compounds mostly exist in the form of molecules. Atoms and molecules can either gain or lose electrons, forming charged particles called ions.
2. The atomic mass of an element is determined with reference to the mass of carbon as a standard element and is expressed in amu. The fractional atomic masses can be calculated from the relative abundance of isotopes.
3. The composition of a substance is given by its chemical formula. A molecular substance can be represented by its empirical or a molecular formulas.
4. Combustion and molecular formulas are related through a simple integer. and then the molecular formula of a substance by knowing its molar mass.
5. A mole of any substance is the Avogadro’s number of atoms or molecules or formula units of that substance.
6. The study of quantitative relationship b/w the reactants and the products in a balanced chemical equation is known as stiochiometry.
7. The concept of molar volume of gases helps to relate solids and liquids gases in a quantitative manner.
8. A limiting reactant is completely consumed in a reaction and controls quantity of products formed.