Molecular Mass and Mole Concept The molecular mass of an element or compound is the weighted average mass of all the atoms in a molecule. It is determine...
The molecular mass of an element or compound is the weighted average mass of all the atoms in a molecule. It is determined by adding the atomic masses of all the atoms in the molecule, taking into account their relative proportions.
For example, consider the compound water (H2O). The molecular mass of water is the average mass of two hydrogen atoms and one oxygen atom. The atomic mass of hydrogen is 1 and the atomic mass of oxygen is 16. Therefore, the molecular mass of water is:
The mole is a more familiar unit of measure for mass. A mole is a quantity of a substance that contains exactly 6.022 x 10^23 particles of that substance.
For example, 1 mole of water contains 6.022 x 10^23 molecules of water. This means that 1 gram of water contains this same number of molecules as 1 mole of water.
The molecular mass and mole concept are used to understand a variety of properties of substances, such as their melting point, boiling point, and chemical reactivity