Explain the concept of molar mass.

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol).

In more detail, molar mass is a fundamental concept in chemistry that links the microscopic world of atoms and molecules to the macroscopic world of grams and kilograms. It is defined as the mass of one mole of a substance. A mole is a unit of measurement in chemistry, representing 6.02 x 10^23 particles (atoms, molecules, ions, etc.). This number is known as Avogadro's number.

The molar mass of an element is numerically equal to the element's relative atomic mass in g/mol. For example, the relative atomic mass of hydrogen (H) is approximately 1, therefore, the molar mass of hydrogen is approximately 1 g/mol. Similarly, the molar mass of oxygen (O) with a relative atomic mass of 16 is 16 g/mol.

For compounds, the molar mass is calculated by adding up the molar masses of all the atoms in the compound. For instance, water (H2O) has a molar mass of approximately 18 g/mol, calculated by adding the molar masses of two hydrogen atoms (2 x 1 g/mol) and one oxygen atom (16 g/mol).

Molar mass is a crucial concept in many chemical calculations, including stoichiometry, gas laws, and solution concentration. It allows chemists to convert between the mass of a substance and the number of moles, providing a bridge between the atomic and macroscopic worlds. Understanding and being able to calculate molar mass is a fundamental skill in chemistry.