The number of atoms, molecules, formula units or ions in one gram atom, one gram molecule, one gram formula unit or one gram ion, respectively is called Avogadro’s number. OR The number of atoms, molecules, formula units or ions in one mole of the substance is called Avogadro’s number. Representation of Avogadro’s Number: It is…
Below are some important points to get clear mole concept, definition of mole chemistry and mole units. Mole can be define as, The atomic mass, molecular mass, ionic mass or formula mass of a substance expressed in grams is called mole of that substance. OR The amount of a substance, which contains 6.02 x 1023…
An analytical procedure in which an organic compound is burnt to determine the percentage of each element present in the compound is called combustion analysis. In combustion analysis, weighed amount of an organic compound is burnt in the stream of oxygen in a closed tube known as combustion tube. At the end of this tube…
A formula which tells the relative number of atoms present in a compound is known as empirical formula. Examples: NaCl, HO and CH2O are the empirical formulas of sodium chloride, hydrogen peroxide and glucose respectively. Determination of Empirical Formula for Organic Compounds: To determine empirical formula percentage of each element present in a compound is…
A formula which tells the actual number of atoms present in a molecule of a substance is known as molecular formula. Examples: H2O2 and C6H12O6 are the molecular formulas of hydrogen peroxide and glucose respectively.
Many elements exist as a mixture of their isotopes. The atomic masses of such elements depend upon the number of their isotopes and their natural abundances. This is why their atomic masses are in fraction. This can be explained through following example, EXAMPLE: A sample of neon is found to consist of 20Ne, 21Ne and…