Calculate the molar mass for each of the following:
a. Al₂(SO₄)₃, antiperspirant

Verified step by step guidance

1. Step 1: Identify the elements in the compound Al₂(SO₄)₃ and their respective quantities. The formula indicates 2 aluminum (Al) atoms, 3 sulfur (S) atoms, and 12 oxygen (O) atoms (since each sulfate ion, SO₄, contains 4 oxygen atoms and there are 3 sulfate ions).
2. Step 2: Look up the atomic masses of each element from the periodic table. For example, the approximate atomic masses are: Al = 26.98 g/mol, S = 32.07 g/mol, and O = 16.00 g/mol.
3. Step 3: Multiply the atomic mass of each element by the number of atoms of that element in the compound. For aluminum: 2 × 26.98 g/mol. For sulfur: 3 × 32.07 g/mol. For oxygen: 12 × 16.00 g/mol.
4. Step 4: Add the contributions of all the elements together to calculate the total molar mass of Al₂(SO₄)₃. This is done by summing the results from Step 3.
5. Step 5: Express the final molar mass in units of g/mol, which represents the mass of one mole of Al₂(SO₄)₃.

Key Concepts

Molar Mass

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 all the atoms in a chemical formula. Understanding molar mass is essential for converting between grams and moles, which is crucial in stoichiometry and chemical reactions.

Chemical Formula

A chemical formula represents the composition of a compound, indicating the types and numbers of atoms present. For example, Al₂(SO₄)₃ shows that the compound contains 2 aluminum (Al) atoms, 3 sulfate (SO₄) groups, and helps in determining the molar mass by identifying each element's contribution.

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It involves using molar mass to calculate the amounts of substances consumed or produced, making it essential for understanding how to balance equations and perform calculations in chemical processes.