What is the molar mass for MgO?
The correct answer and explanation is:
Molar Mass of MgO:
The molar mass of magnesium oxide (MgO) is 40.30 g/mol.
Explanation (Approx. 300 Words)
Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of the elements in a compound, based on their proportions in the chemical formula.
Magnesium oxide (MgO) is a binary ionic compound made of magnesium (Mg) and oxygen (O). Each formula unit of MgO contains one magnesium atom and one oxygen atom. To determine its molar mass, we refer to the atomic masses from the periodic table:
- Atomic mass of magnesium (Mg) ≈ 24.31 g/mol
- Atomic mass of oxygen (O) ≈ 16.00 g/mol
Now, add these values together: Molar mass of MgO=24.31 g/mol (Mg)+16.00 g/mol (O)=40.31 g/mol\text{Molar mass of MgO} = 24.31\, \text{g/mol (Mg)} + 16.00\, \text{g/mol (O)} = 40.31\, \text{g/mol}
Due to rounding conventions and significant figures, this is often written as 40.30 g/mol in many textbooks and chemical references.
Why Molar Mass is Important
Molar mass is essential in chemistry because it acts as a bridge between the microscopic world of atoms and the macroscopic world of grams and liters in the laboratory. For example, if you need to prepare a reaction involving 1 mole of MgO, you would weigh out 40.30 grams.
MgO is an important compound used in various industrial and biological processes. It is a basic oxide and reacts with acids, forming salts and water. It also has applications in refractory materials due to its high melting point.
Understanding the molar mass allows chemists to perform stoichiometric calculations, balance chemical equations, and convert between grams, moles, and atoms accurately.