Problem 21 - Chemistry: An Atoms-Focused Approach

Question

Write a balanced chemical equation for each of the following reactions: a. Dinitrogen pentoxide reacts with sodium metal to produce sodium nitrate and nitrogen dioxide. b. A mixture of nitric acid and nitrous acid is formed when water reacts with dinitrogen tetroxide. c. At high pressure, nitrogen monoxide decomposes to dinitrogen monoxide and nitrogen dioxide.

Step-by-Step Solution

Answer

Question: Write the balanced chemical equations for the following reactions: a. Dinitrogen pentoxide reacts with sodium metal to produce sodium nitrate and nitrogen dioxide. b. A mixture of nitric acid and nitrous acid is formed when water reacts with dinitrogen tetroxide. c. At high pressure, nitrogen monoxide decomposes to dinitrogen monoxide and nitrogen dioxide. Answer: a. 2N2O5 + 10Na -> 5NaNO3 + 2NO2 b. N2O4 + 2H2O -> HNO3 + 3HNO2 c. 3NO -> N2O + 2NO2

Step 1: Write the unbalanced equation

First, identify the reactants and products and write their chemical formulas: Dinitrogen pentoxide (N2O5), Sodium metal (Na), Sodium nitrate (NaNO3), Nitrogen dioxide (NO2). Now, write the unbalanced equation: N2O5 + Na -> NaNO3 + NO2

Step 2: Balance the equation

To balance the equation, adjust the stoichiometric coefficients so that the number of atoms for each element is the same on both sides of the arrow: 2N2O5 + 10Na -> 5NaNO3 + 2NO2 So, the balanced chemical equation is: 2N2O5 + 10Na -> 5NaNO3 + 2NO2 #b. A mixture of nitric acid and nitrous acid is formed when water reacts with dinitrogen tetroxide.#

Step 3: Write the unbalanced equation

First, identify the reactants and products and write their chemical formulas: Dinitrogen tetroxide (N2O4), Water (H2O), Nitric acid (HNO3), Nitrous acid (HNO2). Now, write the unbalanced equation: N2O4 + H2O -> HNO3 + HNO2

Step 4: Balance the equation

To balance the equation, adjust the stoichiometric coefficients so that the number of atoms for each element is the same on both sides of the arrow: N2O4 + 2H2O -> HNO3 + 3HNO2 So, the balanced chemical equation is: N2O4 + 2H2O -> HNO3 + 3HNO2 #c. At high pressure, nitrogen monoxide decomposes to dinitrogen monoxide and nitrogen dioxide.#

Step 5: Write the unbalanced equation

First, identify the reactants and products and write their chemical formulas: Nitrogen monoxide (NO), Dinitrogen monoxide (N2O), Nitrogen dioxide (NO2). Now, write the unbalanced equation: NO -> N2O + NO2

Step 6: Balance the equation

To balance the equation, adjust the stoichiometric coefficients so that the number of atoms for each element is the same on both sides of the arrow: 3NO -> N2O + 2NO2 So, the balanced chemical equation is: 3NO -> N2O + 2NO2

Key Concepts

Stoichiometry

Stoichiometry is a cornerstone concept in chemistry, helping us understand the proportion of reactants and products in a chemical reaction. At its core, stoichiometry is about the quantified relationships between the amounts of reactants used and the products formed in a chemical reaction. This is founded on the principle that atoms are conserved in a chemical reaction, which means what goes into the reaction must come out. Consider the reaction: - In the process of decomposing nitrogen monoxide to produce dinitrogen monoxide and nitrogen dioxide, for every 3 molecules of nitrogen monoxide (NO) used, 1 molecule of dinitrogen monoxide ( N2O ) and 2 molecules of nitrogen dioxide ( NO2 ) are produced. Using stoichiometry, we not only keep track of that, but also help us calculate how much of each substance we would need or how much we can expect to get based on the molecular weights of the molecules involved. By multiplying the number of molecules by their molar mass, chemists can determine the exact mass of reactants needed and products formed.

Balancing Chemical Equations

Balancing chemical equations is fundamental in chemical reactions to ensure the law of conservation of mass is upheld. This means that atoms cannot simply appear or disappear; they need to be accounted for on both sides of the equation. To achieve this, stoichiometric coefficients are used, which are numbers placed in front of compounds.For example, consider the balancing of the equation involving dinitrogen pentoxide (N2O5) and sodium (Na):- Start with the unbalanced form: \( ext{N2O5 + Na} \to \text{NaNO3 + NO2} \)- Count the number of atoms for each element on both sides.- Adjust coefficients, aiming to equalize the number of each type of atom:\( 2 ext{N2O5 + 10 Na} \to \text{5 NaNO3 + 2 NO2} \) Successfully balancing the equation shows that 2 molecules of N2O5 react with 10 atoms of Na to yield 5 molecules of sodium nitrate (NaNO3) and 2 molecules of NO2. This meticulous process ensures the equation accurately reflects reality and is crucial for any further calculations or experimental planning.

Decomposition Reactions

In chemistry, decomposition reactions involve the breakdown of a compound into simpler components. They are starkly characterized by a single reactant forming two or more products. This type of reaction is often triggered under certain conditions, such as heating, applying pressure, or using catalysts.A perfect example is the decomposition of nitrogen monoxide (NO) under high pressure. Here, it's fascinating to see how one compound can break down to form a blend of new substances: - In the given reaction: \( 3 ext{NO} \to ext{N2O + 2NO2} \)- Nitrogen monoxide decomposes to form dinitrogen monoxide and nitrogen dioxide. This simple illustration underlines how powerful and significant decomposition reactions can be in chemistry. They are crucial processes in a variety of settings, such as creating new materials, recycling elements, and even in biological systems. Understanding how and why such reactions occur broadens our insight into chemical behavior under different environmental conditions.