Molecular weight, also known as relative molecular mass, is the average mass of a molecule in a substance. It is calculated by adding up the atomic weights of all the atoms present in the molecule.
Molecular weight can be measured experimentally using techniques such as mass spectrometry or gel permeation chromatography. It can also be calculated using the atomic weights of each element and the number of atoms in the molecule.
Molecular weight is important in chemistry because it helps determine the physical and chemical properties of a substance. It is also used to calculate the concentration of a solution and to determine the amount of a substance needed for a reaction.
Molecular weight and molar mass are often used interchangeably, but they are not exactly the same. Molecular weight refers to the mass of a single molecule, while molar mass refers to the mass of one mole of a substance. Molar mass is calculated by multiplying the molecular weight by Avogadro's number (6.022 x 10^23).
The number and types of atoms present in a molecule can affect its molecular weight. Isotopes of elements can also affect the molecular weight. Additionally, the structure and arrangement of atoms in a molecule can also impact its molecular weight.