The molecular weight of potash alum, also known as potassium alum, is approximately 474.38 grams per mole (g/mol). This value represents the sum of the atomic masses of all the elements present in the compound.
Potash alum has the chemical formula KAl(SO4)2·12H2O. Breaking down the formula, we can calculate its molecular weight as follows:
- Atomic mass of potassium (K): 39.10 g/mol
- Atomic mass of aluminum (Al): 26.98 g/mol
- Atomic mass of sulfur (S): 32.07 g/mol
- Atomic mass of oxygen (O): 16.00 g/mol
- Atomic mass of hydrogen (H): 1.01 g/mol
Multiplying the respective atomic masses with the number of atoms in the formula and adding them up:
(1 × K) + (1 × Al) + (2 × S) + (8 × O) + (24 × H2O) = 39.10 + 26.98 + (2 × 32.07) + (8 × 16.00) + (24 × 1.01) = 474.38 g/mol
Therefore, the molecular weight of potash alum is approximately 474.38 g/mol.