Question

Write the chemical equations for the complete combustion of ethane, ethene, and ethyne into carbon dioxide and water. (Chapter 9)

Short answer

The balanced chemical equations for the complete combustion of ethane, ethene, and ethyne into carbon dioxide and water are: 1. Ethane (C2H6) combustion: \(C2H6 + \frac{7}{2}O2 \rightarrow 2CO2 + 3H2O\) 2. Ethene (C2H4) combustion: \(C2H4 + 3O2 \rightarrow 2CO2 + 2H2O\) 3. Ethyne (C2H2) combustion: \(C2H2 + \frac{5}{2}O2 \rightarrow 2CO2 + H2O\)

Step-by-step solution

Write the unbalanced chemical equations for the combustion of ethane, ethene and ethyne.

Begin by writing the chemical formulas for each hydrocarbon and then combining it with oxygen (O2) to form carbon dioxide (CO2) and water (H2O). The combustion reactions for each of the hydrocarbons are as follows: 1. Ethane (C2H6) combustion: C2H6 + O2 ⟶ CO2 + H2O 2. Ethene (C2H4) combustion: C2H4 + O2 ⟶ CO2 + H2O 3. Ethyne (C2H2) combustion: C2H2 + O2 ⟶ CO2 + H2O Note that these equations are not yet balanced.

Balance the chemical equations for the combustion of ethane, ethene, and ethyne.

We'll need to balance the carbon, hydrogen, and oxygen atoms in the reactants and products for each equation. Here's how to do it: 1. Ethane (C2H6) combustion: C2H6 + \(\frac{7}{2}\)O2 ⟶ 2CO2 + 3H2O 2. Ethene (C2H4) combustion: C2H4 + 3O2 ⟶ 2CO2 + 2H2O 3. Ethyne (C2H2) combustion: C2H2 + \(\frac{5}{2}\)O2 ⟶ 2CO2 + H2O Now, all three combustion reactions are balanced with the correct atoms on both sides of each equation.

Key concepts

Chemical Equations

Chemical equations are symbolic representations of chemical reactions, where the reactants are shown on the left side and the products on the right, separated by an arrow indicating the direction of the reaction. To illustrate, consider the combustion reactions for three different hydrocarbons: ethane, ethene, and ethyne.

A simple chemical equation for the combustion of ethane is written as:
\[ C_2H_6 + O_2 \longrightarrow CO_2 + H_2O \]
However, this equation is yet to be balanced, meaning the number of atoms of each element on the reactant side does not yet match the number on the product side. Writing chemical equations correctly is crucial in chemistry as it ensures the law of conservation of mass is upheld, meaning all atoms are accounted for. When drafting these symbolic glyphs, it's essential to be familiar with the chemical formulas of compounds and the physical states of reactants and products.

Hydrocarbon Combustion

Hydrocarbon combustion is a type of chemical reaction where a hydrocarbon reacts with oxygen to yield carbon dioxide and water as products, releasing energy in the form of heat and light. It is a highly exothermic process that is fundamental to many energy-producing systems, such as engines and power plants.

For instance, the combustion of ethane, a simple hydrocarbon, is expressed by the chemical equation:
\[ C_2H_6 + O_2 \longrightarrow CO_2 + H_2O \]
During the combustion process, the carbon in the hydrocarbon oxidizes to form carbon dioxide, while the hydrogen oxidizes to form water. This process is ubiquitous and is the bedrock of energy release in fossil fuels. Ethene and ethyne, similarly, undergo combustion to yield the same types of products, carbon dioxide, and water, but in different ratios based on their individual molecular structures.

Balancing Chemical Equations

Balancing chemical equations is a critical step in the study of chemistry, as it ensures that the same number of atoms for each element is present on both sides of the equation, in line with the law of conservation of mass.

To balance the equation for the combustion of ethane, you'd proceed as follows:
\[ C_2H_6 + \frac{7}{2}O_2 \longrightarrow 2CO_2 + 3H_2O \]
This means for every molecule of ethane, you'll need three and a half molecules of oxygen to yield two molecules of carbon dioxide and three molecules of water. Balancing these equations requires patience and attention to detail, ensuring that for every atom entering a reaction, an identical atom exits. A balanced equation provides a clear picture of the stoichiometry, which is the quantitative relationship between reactants and products in a chemical reaction, enabling accurate predictions in chemical processes.