CBSE Class 11-science Chemistry Some Basic Concepts of Chemistry
Importance and Scope of Chemistry
Significant Figures are numbers that are known with certainty.
Whenever we add or subtract numbers with significant figures the result cannot have more figures to the right of the decimal point than either of the original numbers.
In case of multiplication and division, the answer cannot have more significant figures than any of the original numbersLaws of Chemical Combination
Laws of Chemical CombinationFormulation and Calculation
Mass percentage gives the mass of each element expressed as the percentage of total mass
Molecular formula gives the actual no. of atoms of various elements present in 1 molecule of the compound
Empirical formula gives the simple whole no. ratio of the atoms of various elements present in 1 molecule of the compoundMole Concept
Mole fraction of a component in a solution is equal to the ratio of no. of moles of that component to the total no. of moles.
The molarity of a substance in solution is defined as the number of moles of solute per litre of solution.
Molality is defined as the no. of moles of the solute in 1kg of solventMass and Stoichiometry
One mole is the amount of a substance that contains as many particles as there are atoms in exactly 12 g of the c-12 isotope
The mass of one mole of a substance in grams is called its molar mass.
A reactant that is completely consumed in a chemical reaction is called limiting reagent.
