What is the molar mass of PCL3
The correct answer and explanation is:
The molar mass of PCl₃ (phosphorus trichloride) is 137.33 g/mol.
To calculate the molar mass of PCl₃, begin by identifying the atomic masses of its constituent elements:
- Phosphorus (P): 30.97 g/mol
- Chlorine (Cl): 35.45 g/mol
Phosphorus trichloride contains one atom of phosphorus and three atoms of chlorine. Multiply the atomic mass of each element by the number of atoms and add the values together:
- 1 × 30.97 g/mol = 30.97 g/mol
- 3 × 35.45 g/mol = 106.35 g/mol
Now, sum the two values:
30.97 g/mol + 106.35 g/mol = 137.32 g/mol
Rounded to two decimal places, the molar mass is 137.33 g/mol.
Understanding molar mass is important because it allows conversion between grams and moles in chemical calculations. Molar mass acts as a bridge in stoichiometry. If given a mass of PCl₃, dividing by its molar mass gives the number of moles. This is essential in reactions where quantities of substances must be calculated based on balanced chemical equations.
For example, in a chemical reaction involving PCl₃, determining how much is needed or produced requires converting between grams and moles. This ensures the correct proportions of reactants and products.
PCl₃ is a covalent compound and commonly used in the synthesis of organophosphorus compounds. Knowing its molar mass helps in preparing solutions, analyzing yields, and balancing chemical reactions. It also plays a role in thermodynamic and kinetic calculations, such as determining enthalpy changes or reaction rates.
Overall, the molar mass is a foundational concept in chemistry that supports both theoretical and practical applications, from lab work to industrial processes.