Problem 23 - Chemistry: An Atoms-Focused Approach

Question

Nitrogen and oxygen can combine to form different nitrogen oxides that play a minor role in the chemistry of smog. Write balanced chemical equations for the reactions of \(\mathrm{N}_{2}\) and \(\mathrm{O}_{2}\) that produce (a) \(\mathrm{N}_{2} \mathrm{O}\) and (b) \(\mathrm{N}_{2} \mathrm{O}_{5}\).

Step-by-Step Solution

Answer

Question: Write the balanced chemical equations for the following reactions: (a) The reaction between nitrogen (N2) and oxygen (O2) to form nitrous oxide (N2O). (b) The reaction between nitrogen (N2) and oxygen (O2) to form dinitrogen pentoxide (N2O5). Answer: (a) N2 + O2 → 2N2O (b) 2N2 + 5O2 → 2N2O5

Step 1: (a) Writing the unbalanced equation for N2 + O2 → N2O

Start by combining the reactants (N2 and O2) and products (N2O) as follows: N2 + O2 → N2O

Step 2: (a) Balancing the chemical equation for N2 + O2 → N2O

To balance the equation, adjust the coefficients so that the same number of each atom appears on both sides of the arrow: N2 + O2 → 2N2O Now, the equation is balanced, with 2 nitrogen atoms and 2 oxygen atoms on each side.

Step 3: (b) Writing the unbalanced equation for N2 + O2 → N2O5

Start by combining the reactants (N2 and O2) and products (N2O5) as follows: N2 + O2 → N2O5

Step 4: (b) Balancing the chemical equation for N2 + O2 → N2O5

To balance the equation, adjust the coefficients so that the same number of each atom appears on both sides of the arrow: N2 + 2.5O2 → N2O5 However, we cannot have fractional coefficients in a balanced equation. To get whole number coefficients, multiply the entire equation by 2: 2N2 + 5O2 → 2N2O5 Now, the equation is balanced, with 4 nitrogen atoms and 10 oxygen atoms on each side.

Key Concepts

Nitrogen Oxides

Nitrogen oxides, commonly known as NOx, are compounds formed by the reaction between nitrogen and oxygen in various proportions. One of the key players in the chemistry surrounding smog, nitrogen oxides include various species such as - nitric oxide (\( ext{NO} \))- nitrogen dioxide (\( ext{NO}_2 \))- and nitrous oxide (\( ext{N}_2 ext{O} \))The formation of these compounds often occurs via combustion processes, like those in car engines, where high temperatures enable the reaction between nitrogen and oxygen from the air.
One of the exercises involves balancing reactions that form nitrous oxide (\( ext{N}_2 ext{O} \)) and nitrogen pentoxide (\( ext{N}_2 ext{O}_5 \)). These oxides not only contribute to air pollution but also have various applications, such as in anesthesia and as precursors to other chemical compounds. Understanding the formation and balancing of nitrogen oxide chemical equations help us gauge their impact on the environment and industry.

Chemical Equations

Chemical equations are symbolic representations of chemical reactions. They show the transformation of reactants into products.
Each equation involves reactants on the left side and products on the right, separated by an arrow pointing toward the products. In the context of nitrogen oxides, the reactants are \( ext{N}_2 \) (nitrogen) and \( ext{O}_2 \) (oxygen).
When writing unbalanced chemical equations, the formula only reflects the substances involved and not the quantities. Balancing a chemical equation is crucial because it ensures that no atoms are lost or gained in the reaction, respecting the law of conservation of mass.

- For example, the unbalanced reaction for producing nitrous oxide is \( ext{N}_2 + ext{O}_2 ightarrow ext{N}_2 ext{O} \).
- And after balancing, it becomes \( ext{N}_2 + ext{O}_2 ightarrow 2 ext{N}_2 ext{O} \), ensuring the same number of nitrogen and oxygen atoms on each side.
Balancing chemical equations requires adjusting coefficients to align the number of each kind of atom equivalent on both sides, providing insight into the proportions required for the reaction.

Stoichiometry

Stoichiometry is the study of the quantitative relationships or ratios between reactants and products in a chemical reaction. It uses balanced chemical equations to connect the proportions of molecules or moles necessary for the reaction. For reactions involving nitrogen oxides, stoichiometry helps determine the exact amounts of nitrogen and oxygen needed to form a given amount of product, like \( ext{N}_2 ext{O}_5 \).
In the balanced equation \( 2 ext{N}_2 + 5 ext{O}_2 ightarrow 2 ext{N}_2 ext{O}_5 \), the coefficients indicate

- 2 moles of \( ext{N}_2 \) require 5 moles of \( ext{O}_2 \) to form 2 moles of \( ext{N}_2 ext{O}_5 \).

This information isn't just academic; it is essential in laboratory and industrial chemistry to ensure efficient use of reagents minimizing waste and optimizing reactions for desired yields.
Understanding stoichiometry allows you to

- predict quantities,- plan reactions,- and optimize conditions for desirable chemical syntheses.

This mix of chemistry and math is foundational for anyone working with chemical reactions.