What is the molar mass of PbCl2
The Correct Answer and Explanation is :
The molar mass of lead(II) chloride (PbCl₂) can be calculated by adding the atomic masses of its constituent elements: lead (Pb) and chlorine (Cl).
- Atomic Mass of Lead (Pb): The atomic mass of lead is approximately 207.2 g/mol.
- Atomic Mass of Chlorine (Cl): The atomic mass of chlorine is approximately 35.5 g/mol. Since there are two chlorine atoms in lead(II) chloride, we multiply this value by 2.
Now, we calculate the molar mass of PbCl₂:
[
\text{Molar mass of PbCl}_2 = (\text{Atomic mass of Pb}) + 2 \times (\text{Atomic mass of Cl})
]
Substituting the values:
[
\text{Molar mass of PbCl}_2 = 207.2 \, \text{g/mol} + 2 \times 35.5 \, \text{g/mol}
]
[
= 207.2 \, \text{g/mol} + 71.0 \, \text{g/mol}
]
[
= 278.2 \, \text{g/mol}
]
Thus, the molar mass of lead(II) chloride (PbCl₂) is approximately 278.2 g/mol.
Explanation
Molar mass is a fundamental concept in chemistry that allows us to relate the mass of a substance to the amount of substance (in moles). It is particularly important for stoichiometric calculations in chemical reactions. For compounds like lead(II) chloride, which consist of more than one element, the molar mass is the sum of the atomic masses of all atoms present in the formula.
Understanding molar mass is crucial when preparing solutions, conducting reactions, or determining yields. For example, if you wanted to prepare a specific molarity of PbCl₂ solution, knowing its molar mass enables accurate calculations of the mass needed for a given volume.
In practical applications, PbCl₂ is often used in various chemical processes, including organic synthesis and as a precursor for other lead compounds. Knowing its molar mass helps chemists to measure and mix reagents precisely, ensuring proper reaction conditions and yields.