Question

How many moles of chlorine are present in 2.47 g of phosphorus pentachloride?

Answer 1

Hint: Mole is generally represented by the symbol mol. It is generally described as the unit of measurement for the amount of substance in SI where SI stands for International System of units. It is defined on the basis of Avogadro’s number.

Complete step-by-step answer: A mole of a substance or particle can be defined as containing exactly $6.02214076\times {{10}^{23}}$ particles which may be atoms, molecules or ions where $6.02214076\times {{10}^{23}}$ is known as the Avogadro’s number.
Now to calculate the number of moles in 2.47 grams of $PC{{l}_{5}}$ we first have to calculate the molecular weight of $PC{{l}_{5}}$. The molecular weight of substance is defined as the weight in atomic mass units of each of the atoms in a given formula where an atomic mass unit is described as 1/12^th the weight of the carbon-12 isotope. The molecular weight of a material is required to tell an individual how many grams there are in one mole of that chemical substance i.e. molecular weight of any substance contains 1 mole of that substance.
Molecular weight of $PC{{l}_{5}}$= 208.5 g
This defines that 208.5 g of $PC{{l}_{5}}$ contains = 1 mole of substance
Then 2.47 g of $PC{{l}_{5}}$ contains = 0.01185 moles of $PC{{l}_{5}}$.
With a ratio 5:1 of chlorine to compound which represents $0.01185\times 5=0.0592$ moles of chlorine.
Hence we can say that 0.0592 moles of chlorine are present in 2.47 g of $PC{{l}_{5}}$.

Note: Phosphorus pentachloride is one of the most important phosphorus chlorides which is used as a chlorinating agent. This is colorless in nature if it is contaminated with hydrogen chloride then it became pale yellow in color.