Problem 22 - Chemistry: An Atoms-Focused Approach

Question

Write a balanced chemical equation for each of the following reactions: a. Hydrazine, \(\mathrm{N}_{2} \mathrm{H}_{4},\) reacts with oxygen to produce water and the element nitrogen. b. Ammonia (NH_) burns in oxygen to produce elemental nitrogen and water. c. Silicon dioxide reacts with carbon to produce the element silicon and carbon monoxide.

Step-by-Step Solution

Answer

Question: Write the balanced chemical equations for the following reactions: a. Reaction between hydrazine and oxygen, producing water and nitrogen. b. Reaction between ammonia and oxygen, producing nitrogen and water. c. Reaction between silicon dioxide and carbon, producing silicon and carbon monoxide. Answer: a. N₂H₄ + O₂ → 2H₂O + N₂ b. 4NH₃ + 3O₂ → 2N₂ + 6H₂O c. SiO₂ + 2C → Si + 2CO

Step 1: Write the unbalanced equation

First, write the unbalanced chemical equation for the reaction between hydrazine and oxygen. \(__ \mathrm{N}_{2} \mathrm{H}_{4} + \_\mathrm{O}_{2} \rightarrow \_\mathrm{H}_{2}\mathrm{O} + \_\mathrm{N}_{2}\)

Step 2: Balance the equation

Now balance the equation by finding the appropriate coefficients for the reactants and products such that the number of atoms is the same on both sides of the equation. \(1 \mathrm{N}_{2} \mathrm{H}_{4} + 1\mathrm{O}_{2} \rightarrow 2\mathrm{H}_{2}\mathrm{O} + 1\mathrm{N}_{2}\) So, the balanced chemical equation for this reaction is: \(\mathrm{N}_{2} \mathrm{H}_{4} + \mathrm{O}_{2} \rightarrow 2\mathrm{H}_{2}\mathrm{O} + \mathrm{N}_{2}\) #b. Reaction between ammonia and oxygen, producing nitrogen and water#

Step 3: Write the unbalanced equation

First, write the unbalanced chemical equation for the reaction between ammonia and oxygen. \(__ \mathrm{NH}_{3} + \_\mathrm{O}_{2} \rightarrow \_\mathrm{N}_{2} + \_\mathrm{H}_{2}\mathrm{O}\)

Step 4: Balance the equation

Now balance the equation by finding the appropriate coefficients for the reactants and products such that the number of atoms is the same on both sides of the equation. \(4 \mathrm{NH}_{3} + 3\mathrm{O}_{2} \rightarrow 2\mathrm{N}_{2} + 6\mathrm{H}_{2}\mathrm{O}\) So, the balanced chemical equation for this reaction is: \(4\mathrm{NH}_{3} + 3\mathrm{O}_{2} \rightarrow 2\mathrm{N}_{2} + 6\mathrm{H}_{2}\mathrm{O}\) #c. Reaction between silicon dioxide and carbon, producing silicon and carbon monoxide#

Step 5: Write the unbalanced equation

First, write the unbalanced chemical equation for the reaction between silicon dioxide and carbon. \(__ \mathrm{SiO}_{2} + \_\mathrm{C} \rightarrow \_\mathrm{Si} + \_\mathrm{CO}\)

Step 6: Balance the equation

Now balance the equation by finding the appropriate coefficients for the reactants and products such that the number of atoms is the same on both sides of the equation. \(1 \mathrm{SiO}_{2} + 2\mathrm{C} \rightarrow 1\mathrm{Si} + 2\mathrm{CO}\) So, the balanced chemical equation for this reaction is: \(\mathrm{SiO}_{2} + 2\mathrm{C} \rightarrow \mathrm{Si} + 2\mathrm{CO}\)

Key Concepts

Chemical Reactions

Chemical reactions are processes where substances, known as reactants, transform into different substances, known as products. These reactions involve the making and breaking of chemical bonds and can be observed in everyday life, such as when metal rusts or when food is cooked. When writing chemical equations to represent these reactions, it's crucial to indicate the reactants and the products clearly while also showing the number of atoms involved. A chemical equation uses symbols and formulas to show what happens at the molecular level in a reaction. Each element present in the reaction is represented by its chemical symbol, and the number of each type of atom is indicated using coefficients. Understanding chemical reactions is fundamental in chemistry as it helps predict the behavior of substances under different conditions.

• Reactants are the starting materials in a chemical reaction.
• Products are the substances formed as a result of the reaction.
• Coefficients in a chemical equation represent the number of units of each substance involved.

With this understanding, we can better appreciate how different substances interact and transform into new materials.

Stoichiometry

Stoichiometry is a concept that revolves around the quantitative relationships between the reactants and products in a chemical reaction. It comes from the Greek words "stoicheion" (meaning "element") and "metron" (meaning "measure"), and is essential for calculating the amounts of substances consumed and produced in reactions. By using stoichiometry, chemists can predict the masses, volumes, and number of particles consumed and produced. For each balanced equation, the coefficients provide the ratio between the different substances involved in the reaction. This ratio is used to calculate the amount of any reactant needed or product formed.

• It helps in determining the exact amounts of reactants required to produce a desired amount of product.
• It allows chemists to ensure reactions proceed with minimal waste by predicting the limiting reactant.
• Conversion of units like moles to grams is a common application in stoichiometry.

Using stoichiometry effectively is key to controlling and optimizing chemical reactions in the lab or industry.

Reaction Balancing

Balancing chemical equations is an essential skill in chemistry, ensuring the conservation of mass and the correct proportions of reactants and products. When equations are balanced, they reflect the laws of conservation, particularly the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, the number of atoms of each element must be the same on both sides of the equation. To achieve this, we adjust the coefficients placed before each compound without altering the chemical formulas of the reactants or products.

Balancing involves the following steps:

• Start by writing the unbalanced equation, listing all reactants and products.
• Adjust the coefficients to make sure the number of atoms for each element is equal on both sides.
• Prioritize balancing elements that appear in only one reactant and one product first, then move to more complex molecules.

While balancing equations can be challenging at first, practice helps in mastering this skill and understanding both the nature and quantity of substances involved in chemical reactions.