In 3 Moles of Ethane Calculate The Following

This guide explains how to calculate various properties of 3 moles of ethane, including mass, volume, and energy content. Ethane (C₂H₆) is a common hydrocarbon with important applications in industry and energy production.

Calculations for 3 moles of ethane

Ethane is a colorless, odorless gas at room temperature with the chemical formula C₂H₆. When calculating properties of ethane, we typically work with molar quantities because the molar mass provides a consistent reference point.

Key Properties of Ethane

Molar mass: 30.07 g/mol
Standard molar volume at STP: 22.414 L/mol
Standard enthalpy of combustion: -1560 kJ/mol

Using these properties, we can calculate several important quantities for 3 moles of ethane:

Mass of ethane
Volume of ethane at standard temperature and pressure (STP)
Energy content from combustion

Calculating mass of ethane

The mass of a substance can be calculated using the formula:

Mass Calculation Formula

Mass = Number of moles × Molar mass

For 3 moles of ethane with a molar mass of 30.07 g/mol:

Example Calculation

Mass = 3 moles × 30.07 g/mol = 90.21 g

This means 3 moles of ethane weigh approximately 90.21 grams.

Calculating volume of ethane

The volume of a gas at standard temperature and pressure (STP) can be calculated using the formula:

Volume Calculation Formula

Volume = Number of moles × Standard molar volume

At STP, the standard molar volume is 22.414 liters per mole. For 3 moles of ethane:

Example Calculation

Volume = 3 moles × 22.414 L/mol = 67.242 L

This means 3 moles of ethane would occupy approximately 67.242 liters at STP.

Note about STP

Standard Temperature and Pressure (STP) is defined as 0°C (273.15 K) and 1 atmosphere (101.325 kPa). These conditions are used as a reference point for gas volume calculations.

Calculating energy content

The energy content of ethane can be calculated from its standard enthalpy of combustion. The formula is:

Energy Calculation Formula

Energy = Number of moles × Standard enthalpy of combustion

The standard enthalpy of combustion for ethane is -1560 kJ/mol. For 3 moles of ethane:

Example Calculation

Energy = 3 moles × 1560 kJ/mol = 4680 kJ

This means 3 moles of ethane would release approximately 4680 kilojoules of energy when completely combusted.

Energy Units

1 kJ (kilojoule) = 1000 joules. For comparison, 1 kJ is roughly the energy needed to lift a small apple (about 100 grams) 1 meter against gravity.

Frequently Asked Questions

What is the molar mass of ethane?

The molar mass of ethane (C₂H₆) is 30.07 grams per mole. This is calculated by summing the atomic masses of two carbon atoms and six hydrogen atoms.

How do I calculate the volume of ethane at STP?

At standard temperature and pressure (STP), one mole of any gas occupies approximately 22.414 liters. Multiply this by the number of moles to get the total volume.

What is the energy content of ethane?

Ethane has a standard enthalpy of combustion of -1560 kJ/mol, meaning it releases 1560 kilojoules of energy per mole when burned completely.

Is ethane flammable?

Yes, ethane is highly flammable. It forms explosive mixtures with air at concentrations between 3% and 12.5% by volume.