Determining the Volume of Oxygen Gas at STP

Introduction to Gas Volume Calculation

Understanding and calculating the volume of a gas at standard temperature and pressure (STP) are crucial concepts in chemistry. This guide will help you determine the volume of a 11.8 g sample of oxygen gas (O2) at STP, guiding you through the process step-by-step. We will follow the logical sequence of finding the molar mass, calculating the number of moles, and then determining the volume of gas a mole occupies at STP.

Step 1: Identifying the Chemical Compound

Firstly, you need to identify the chemical compound you are working with. Based on the question, it seems you are interested in either oxygen (O2) or methane (CH4). Since the question asks about a sample of oxygen gas, we will proceed with oxygen (O2) for this calculation.

Step 2: Finding the Molar Mass

To begin the calculation, you need to determine the molar mass of the chosen gas. The molar mass is the mass of one mole of the substance, expressed in grams per mole.

For Oxygen (O2): The atomic mass of oxygen (O) is approximately 16 g/mol. Since oxygen gas is O2, you need to account for the two atoms of oxygen. Therefore, the molar mass of O2 is:

Molar Mass of O2 2 x 16 g/mol 32 g/mol

Step 3: Calculating the Number of Moles

The next step is to calculate the number of moles of oxygen gas in the 11.8 g sample. This can be done using the formula:

Number of Moles Given Mass / Molar Mass

Plugging in the numbers:

Number of Moles of O2 11.8 g / 32 g/mol 0.37 moles

Step 4: Determining the Volume of Gas at STP

At STP (Standard Temperature and Pressure), one mole of an ideal gas occupies 22.4 liters (or 22.414 L). This value is a constant and can be used to find the volume of gas at STP. To find the volume of the 0.37 moles of O2, use the formula:

Volume of Gas Number of Moles x 22.4 L/mol

Substituting the values:

Volume of O2 at STP 0.37 moles x 22.4 L/mol 8.384 L

Conclusion: Mastering Gas Volume Calculations

Through the above steps, you can calculate the volume of a 11.8 g sample of oxygen gas at STP. Understanding these calculations is essential for mastering gas laws and their applications in various scientific and engineering fields. Always remember, practice is key to mastering these concepts. Don't hesitate to work through similar problems to solidify your understanding and skills.

Keywords: Molar Mass, STP, Gas Volume Calculation