Calculate Moles of Chlorine Atoms in 0.822 Gram of C2h4cl2

Introduction

Chlorine is a common element in organic chemistry, often found in compounds like C2H4Cl2 (dichloroethane). Calculating the moles of chlorine atoms in a given mass of C2H4Cl2 helps chemists understand the amount of substance present, which is crucial for reaction stoichiometry and solution preparation.

This guide explains how to calculate the moles of chlorine atoms in 0.822 grams of C2H4Cl2 using the compound's molar mass and stoichiometric relationships.

Formula

The number of moles of chlorine atoms in a sample of C2H4Cl2 can be calculated using the following formula:

Where:

• Mass of sample is the given mass of C2H4Cl2 (0.822 grams in this case).
• Number of chlorine atoms per molecule is 2 for C2H4Cl2.
• Molar mass of C2H4Cl2 is calculated by summing the atomic masses of all atoms in the molecule.

Calculation

To calculate the moles of chlorine atoms in 0.822 grams of C2H4Cl2:

1. Determine the molar mass of C2H4Cl2:
   • Carbon (C): 12.01 g/mol × 2 = 24.02 g/mol
   • Hydrogen (H): 1.01 g/mol × 4 = 4.04 g/mol
   • Chlorine (Cl): 35.45 g/mol × 2 = 70.90 g/mol
   • Total molar mass = 24.02 + 4.04 + 70.90 = 98.96 g/mol
2. Use the formula:

   Moles of chlorine = (0.822 g × 2) / 98.96 g/mol ≈ 0.0166 moles

The calculation shows that 0.822 grams of C2H4Cl2 contains approximately 0.0166 moles of chlorine atoms.

Interpretation

The result of 0.0166 moles of chlorine atoms means that there are about 0.0166 × 6.022 × 10²³ ≈ 9.99 × 10²⁰ chlorine atoms in the sample. This interpretation helps in understanding the quantity of chlorine atoms at the molecular level.

In practical terms, this calculation is useful for:

• Determining the amount of chlorine in chemical reactions.
• Preparing solutions with precise chlorine concentrations.
• Understanding stoichiometric relationships in organic chemistry.