What is the molar mass of bromine liquid?
The correct answer and explanation is:
Answer:
The molar mass of liquid bromine (Br₂) is approximately 159.8 g/mol.
Explanation:
1. What is Molar Mass?
Molar mass is the mass of one mole of a substance, usually expressed in grams per mole (g/mol). It tells you how much one mole of molecules or atoms weighs. For elements, the molar mass is numerically equal to the atomic mass found on the periodic table but expressed in g/mol.
2. Bromine in Elemental Form:
Bromine (Br) is a halogen element with an atomic number of 35. In its elemental form at room temperature, bromine exists as a diatomic molecule (Br₂), meaning two bromine atoms are bonded together. This is important because the molar mass must be calculated for the molecule, not just a single atom.
3. Atomic Mass of Bromine:
The atomic mass of a single bromine atom is about 79.9 atomic mass units (amu), which corresponds to 79.9 g/mol when considering molar mass.
4. Calculating Molar Mass of Br₂:
Since bromine naturally exists as Br₂ molecules, the molar mass is: Molar mass of Br2=2×79.9 g/mol=159.8 g/mol\text{Molar mass of Br}_2 = 2 \times 79.9 \, \text{g/mol} = 159.8 \, \text{g/mol}
This means one mole of bromine molecules (Br₂) weighs 159.8 grams.
5. Physical State and Molar Mass:
The physical state (solid, liquid, gas) of bromine at room temperature does not change its molar mass. Liquid bromine is simply bromine molecules in the liquid phase, so the molar mass remains the same as for Br₂ gas.
6. Why Molar Mass Matters:
Molar mass is a fundamental concept in chemistry used to convert between mass and moles. For example, if you have 159.8 grams of bromine, you have exactly one mole of Br₂ molecules. This is essential for stoichiometric calculations in chemical reactions, determining concentrations in solutions, and understanding material properties.
Summary:
- Bromine exists as Br₂ molecules.
- Atomic mass of Br ≈ 79.9 g/mol.
- Molar mass of Br₂ = 2 × 79.9 = 159.8 g/mol.
- The molar mass is independent of bromine’s physical state (solid, liquid, gas).
Thus, the molar mass of liquid bromine is 159.8 g/mol.