In 3 Moles of Ethane C2h6 Calculate The Following

This guide explains how to calculate various properties of 3 moles of ethane (C2H6), including mass, volume, and other important chemical quantities. Ethane is a hydrocarbon with the chemical formula C2H6, consisting of two carbon atoms and six hydrogen atoms. Understanding these calculations is essential for chemistry students and professionals working with hydrocarbons.

Introduction

Ethane (C2H6) is a common hydrocarbon with important applications in industry, energy production, and chemical synthesis. When dealing with chemical calculations, knowing how to work with moles is fundamental. One mole of any substance contains Avogadro's number (6.022 × 10²³) of particles. For ethane, this means 3 moles contain 18.066 × 10²³ molecules.

Calculating properties of ethane involves understanding molar mass, gas laws, and other chemical principles. This guide will walk you through the key calculations you can perform with 3 moles of ethane.

Calculations

Mass Calculation

The mass of 3 moles of ethane can be calculated using the molar mass of ethane. The molar mass of C2H6 is approximately 30.07 g/mol. The formula for mass is:

Mass = Moles × Molar Mass

For 3 moles of ethane:

Mass = 3 mol × 30.07 g/mol = 90.21 g

This means 3 moles of ethane weigh approximately 90.21 grams.

Volume Calculation

For gases, the volume can be calculated using the ideal gas law, assuming standard temperature and pressure (STP). The formula is:

Volume = (Moles × R × Temperature) / Pressure

Where:

R = 0.0821 L·atm/(mol·K)
Temperature = 273.15 K (0°C at STP)
Pressure = 1 atm (STP)

For 3 moles of ethane at STP:

Volume = (3 × 0.0821 × 273.15) / 1 = 65.57 L

This means 3 moles of ethane gas occupy approximately 65.57 liters at standard conditions.

Molar Volume

The molar volume of a gas at STP is approximately 22.4 L/mol. For 3 moles:

Volume = Moles × Molar Volume

Volume = 3 × 22.4 L/mol = 67.2 L

This is a simplified calculation that assumes ideal behavior.

Formulas

The key formulas used in these calculations are:

Mass = Moles × Molar Mass

Volume (gas) = (Moles × R × Temperature) / Pressure

Molar Volume (STP) = 22.4 L/mol

These formulas are fundamental to chemical calculations and apply to many substances beyond just ethane.

Examples

Example 1: Mass Calculation

If you have 3 moles of ethane with a molar mass of 30.07 g/mol:

Mass = 3 × 30.07 = 90.21 g

So, 3 moles of ethane weigh 90.21 grams.

Example 2: Volume Calculation

For 3 moles of ethane gas at STP:

Volume = (3 × 0.0821 × 273.15) / 1 = 65.57 L

The gas occupies 65.57 liters under standard conditions.

FAQ

What is the molar mass of ethane?: The molar mass of ethane (C2H6) is approximately 30.07 g/mol, calculated by summing the atomic masses of two carbon atoms and six hydrogen atoms.
How do I calculate the mass of 3 moles of ethane?: Multiply the number of moles (3) by the molar mass of ethane (30.07 g/mol) to get the mass: 3 × 30.07 = 90.21 g.
What is the volume of 3 moles of ethane gas at STP?: Using the ideal gas law, the volume is approximately 65.57 liters. The simplified molar volume at STP is 22.4 L/mol, so 3 × 22.4 = 67.2 L.
Can I use these calculations for other hydrocarbons?: Yes, the same principles apply to other hydrocarbons. You just need to know the molar mass of the specific compound you're working with.
What assumptions are made in these calculations?: The volume calculations assume ideal gas behavior and standard temperature and pressure (STP). Real gases may deviate from these assumptions.