What is the molar mass of Ba3(PO4)2
The Correct Answer and Explanation is:
To calculate the molar mass of barium phosphate, Ba₃(PO₄)₂, we add up the atomic masses of all the atoms in the formula.
Step 1: Break down the formula
- Ba₃(PO₄)₂ means:
- 3 atoms of barium (Ba)
- 2 phosphate groups (PO₄)
- Each PO₄ contains 1 phosphorus (P) and 4 oxygen (O) atoms
Step 2: Count the total atoms
- Barium (Ba): 3 atoms
- Phosphorus (P): 2 atoms (1 per phosphate group × 2)
- Oxygen (O): 8 atoms (4 per phosphate group × 2)
Step 3: Use atomic masses (in g/mol)
- Barium (Ba) = 137.33
- Phosphorus (P) = 30.97
- Oxygen (O) = 16.00
Step 4: Multiply and add
- Barium: 3 × 137.33 = 411.99
- Phosphorus: 2 × 30.97 = 61.94
- Oxygen: 8 × 16.00 = 128.00
Total molar mass = 411.99 + 61.94 + 128.00 = 601.93 g/mol
Explanation
Molar mass is the mass of one mole of a substance. It is measured in grams per mole and helps convert between the amount of a substance (in moles) and its mass (in grams). To find the molar mass of a compound like barium phosphate, Ba₃(PO₄)₂, it is important to understand the chemical formula and identify how many atoms of each element are present.
The formula Ba₃(PO₄)₂ shows that the compound contains three barium atoms and two phosphate ions. Each phosphate ion consists of one phosphorus atom and four oxygen atoms. So altogether, the compound has three barium atoms, two phosphorus atoms, and eight oxygen atoms.
Next, we use the periodic table to find the atomic masses of the individual elements. Barium has an atomic mass of 137.33 grams per mole, phosphorus is 30.97 grams per mole, and oxygen is 16.00 grams per mole. Multiplying these values by the number of atoms gives us the mass contribution from each element.
By summing all the contributions, we get the final molar mass. This process is critical in chemistry when calculating the amount of reactants or products in a chemical reaction. Knowing the molar mass allows chemists to relate masses of substances to the number of particles involved in a reaction. For barium phosphate, the calculated molar mass is 601.93 grams per mole. This means one mole of Ba₃(PO₄)₂ weighs 601.93 grams.
