What Mass Of Carbon Dioxide Is Formed In The Combustion Of 78. 7 G Of Acetone?.

What Mass Of Carbon Dioxide Is Formed In The Combustion Of 78. 7 G Of Acetone?

Understanding the combustion of organic compounds such as acetone is fundamental in chemistry, especially when calculating the amount of gases produced during combustion reactions. In this comprehensive guide, we will explore the process of determining the mass of carbon dioxide (CO₂) generated when 78.7 grams of acetone (C₃H₆O) undergoes complete combustion. This analysis involves understanding the chemical reaction, mole calculations, and applying stoichiometry principles to arrive at an accurate result.

Introduction to Acetone and Its Combustion

What Is Acetone?

Acetone, with the chemical formula C₃H₆O, is a common organic solvent used in various industrial and household applications. It is a colorless, volatile, and flammable liquid that belongs to the ketone family. Due to its widespread use, understanding its combustion is important for safety and environmental considerations.

The Combustion Reaction of Acetone

The complete combustion of acetone involves its reaction with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O). The general reaction can be written as:

C₃H₆O + O₂ → CO₂ + H₂O

However, to balance this reaction properly, we need to determine the coefficients that satisfy the law of conservation of mass.

Balancing the Combustion Equation

Step-by-Step Balancing

Let's balance the combustion of acetone:

1. Write the unbalanced equation:

C₃H₆O + O₂ → CO₂ + H₂O

1. Balance the carbon atoms:

C₃H₆O + O₂ → 3 CO₂ + H₂O

1. Balance the hydrogen atoms:

C₃H₆O + O₂ → 3 CO₂ + 3 H₂O

1. Balance the oxygen atoms:

• Left side: C₃H₆O has 1 oxygen atom.
• Right side: 3 CO₂ has 3×2=6 oxygen atoms, and 3 H₂O has 3 oxygen atoms, totaling 9 oxygen atoms.
• Total oxygen atoms on the right: 9
• On the left: 1 (from C₃H₆O) + x (from O₂ molecules)

To balance oxygen:

1 + 2x = 9

2x = 8

x = 4

Thus, the balanced chemical equation is:

C₃H₆O + 4 O₂ → 3 CO₂ + 3 H₂O

Calculating the Moles of Acetone

Determining Molar Mass of Acetone

To convert grams to moles, we need the molar mass of acetone:

• Carbon (C): 12.01 g/mol
• Hydrogen (H): 1.008 g/mol
• Oxygen (O): 16.00 g/mol

Calculating:

(3 × 12.01) + (6 × 1.008) + (1 × 16.00) = 36.03 + 6.048 + 16.00 = 58.078 g/mol

Converting Grams to Moles

Given mass: 78.7 g

Number of moles of acetone:

\[
\text{Moles of C}3\text{H}6\text{O} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{78.7\, \text{g}}{58.078\, \text{g/mol}} \approx 1.355\, \text{mol}
\]

Using Stoichiometry to Find CO₂ Produced

The Stoichiometric Relationship

From the balanced chemical equation:

C₃H₆O + 4 O₂ → 3 CO₂ + 3 H₂O

• 1 mol of acetone produces 3 mol of CO₂.

Therefore, the moles of CO₂ produced from 1.355 mol of acetone:

\[
\text{Moles of CO}_2 = 1.355\, \text{mol} \times 3 = 4.065\, \text{mol}
\]

Calculating the Mass of CO₂

The molar mass of CO₂:

• Carbon: 12.01 g/mol
• Oxygen: 16.00 g/mol (×2)

Total:

12.01 + (2 × 16.00) = 12.01 + 32.00 = 44.01 g/mol

Now, the mass of CO₂ formed:

\[
\text{Mass of CO}_2 = 4.065\, \text{mol} \times 44.01\, \text{g/mol} \approx 178.8\, \text{g}
\]

Final Result and Interpretation

Based on the calculations, when 78.7 grams of acetone undergoes complete combustion, approximately 178.8 grams of carbon dioxide are produced.

Key Takeaways:

• The combustion of acetone results in the formation of CO₂ and H₂O, following a balanced chemical reaction.
• Stoichiometric calculations involve converting grams to moles, applying mole ratios, and converting moles back to grams.
• The amount of CO₂ produced is roughly 2.27 times the initial mass of acetone, highlighting the significant increase in gas volume and mass during combustion.

Factors Affecting the Accuracy of the Calculation

While the above calculation provides a theoretical value, several practical factors can influence the actual amount of CO₂ produced:

Purity of Acetone

Impurities in acetone may reduce the amount of combustion products formed.

Complete Combustion Assumption

This calculation assumes complete combustion; in real-world scenarios, incomplete combustion may occur, producing CO and other byproducts.

Environmental Conditions

Temperature and pressure can affect gas volumes, especially if considering gaseous measurements rather than mass.

Applications and Environmental Implications

Understanding how much CO₂ is produced during acetone combustion is essential for:

• Environmental impact assessments, especially regarding greenhouse gas emissions.
• Industrial safety planning for processes involving acetone burning.
• Designing better combustion systems to minimize CO₂ and other pollutants.

Conclusion

In summary, the combustion of 78.7 grams of acetone results in approximately 178.8 grams of carbon dioxide, assuming complete combustion. This calculation underscores the importance of stoichiometry in chemical reactions and illustrates the significant environmental considerations associated with organic solvent combustion. Mastery of these calculations is vital for chemists, environmental scientists, and engineers working towards safer and greener chemical processes.

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References:

• Zumdahl, S. S., & Zumdahl, S. A. (2014). Chemistry: An Atoms First Approach. Cengage Learning.


• Petrucci, R. H., Herring, F. G., Madura, J. D., & Bissonnette, C. (2017). General Chemistry: Principles & Modern Applications. Pearson.


• Lide, D. R. (Ed.). (2004). CRC Handbook of Chemistry and Physics. CRC Press.

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Note: Always double-check calculations and consider real-world variables when applying theoretical results to practical scenarios.