Question

Balance each of the following equations that describe synthesis reactions. a. \(\operatorname{FeO}(s)+\mathrm{O}_{2}(g) \rightarrow \mathrm{Fe}_{2} \mathrm{O}_{3}(s)\) b. \(\operatorname{CO}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{CO}_{2}(g)\) c. \(\mathrm{H}_{2}(g)+\mathrm{Cl}_{2}(g) \rightarrow \mathrm{HCl}(g)\) d. \(\mathrm{K}(s)+\mathrm{S}_{8}(s) \rightarrow \mathrm{K}_{2} \mathrm{S}(s)\) e. \(\mathrm{Na}(s)+\mathrm{N}_{2}(g) \rightarrow \mathrm{Na}_{3} \mathrm{N}(s)\)

Short answer

The balanced equations are: a. \(2\mathrm{FeO}(s) + \mathrm{O}_{2}(g) \rightarrow \mathrm{Fe}_{2}\mathrm{O}_{3}(s)\) b. \(2\mathrm{CO}(g) + \mathrm{O}_{2}(g) \rightarrow 2\mathrm{CO}_{2}(g)\) c. \(\mathrm{H}_{2}(g) + \mathrm{Cl}_{2}(g) \rightarrow 2\mathrm{HCl}(g)\) d. \(2\mathrm{K}(s) + \frac{1}{8}\mathrm{S}_{8}(s) \rightarrow \mathrm{K}_{2}\mathrm{S}(s)\) e. \(6\mathrm{Na}(s) + \mathrm{N}_{2}(g) \rightarrow 2\mathrm{Na}_{3}\mathrm{N}(s)\)

Step-by-step solution

List each element found in the equation.

Fe, O

Count the number of each element on both sides of the equation.

Fe: 1 on left, 2 on the right O: 3 on the left, 3 on the right

Balance the equation.

Adjust the coefficients: 2FeO + O2 → Fe2O3 Now we have: Fe: 2 on both sides O: 4 on both sides b. Balancing the carbon monoxide and oxygen reaction:

List each element found in the equation.

C, O

Count the number of each element on both sides of the equation.

C: 1 on left, 1 on right O: 3 on left, 2 on right

Balance the equation.

Adjust the coefficients: 2CO + O2 → 2CO2 Now we have: C: 2 on both sides O: 4 on both sides c. Balancing the hydrogen and chlorine reaction:

List each element found in the equation.

H, Cl

Count the number of each element on both sides of the equation.

H: 2 on left, 1 on right Cl: 2 on left, 1 on right

Balance the equation.

Adjust the coefficients: H2 + Cl2 → 2HCl Now we have: H: 2 on both sides Cl: 2 on both sides d. Balancing the potassium and sulfur reaction:

List each element found in the equation.

K, S

Count the number of each element on both sides of the equation.

K: 1 on left, 2 on right S: 8 on left, 1 on right

Balance the equation.

Adjust the coefficients: 2K + (1/8)S8 → K2S Now we have: K: 2 on both sides S: 1 on both sides e. Balancing the sodium and nitrogen reaction:

List each element found in the equation.

Na, N

Count the number of each element on both sides of the equation.

Na: 1 on left, 3 on right N: 2 on left, 1 on right

Balance the equation.

Adjust the coefficients: 6Na + N2 → 2Na3N Now we have: Na: 6 on both sides N: 2 on both sides

Key concepts

Synthesis Reactions

In chemistry, synthesis reactions are a fundamental type of chemical reactions where two or more simple substances combine to form a more complex product. This process can be visualized as A + B → AB, where A and B represent reactants and AB is the compound formed as the product.

For instance, when iron (III) oxide is formed from iron oxide and oxygen gas, it’s a synthesis reaction represented by the chemical equation 2FeO + O₂ → Fe₂O₃. Here, a solid and a gas react to form a new compound through the process of chemical synthesis. Synthesis reactions are crucial and are utilized for various applications, from forming new materials to energy production in biological systems.

Stoichiometry

Stoichiometry is the aspect of chemistry that involves the calculation of reactants and products in chemical reactions. It is based on the conservation of mass where the mass of the reactants equals the mass of the products. This concept necessitates that the amount of each element has to be the same on both sides of a chemical equation.

To understand stoichiometry, consider a simple chemical reaction like 2CO + O₂ → 2CO₂. Here, the reaction between carbon monoxide (CO) and oxygen (O₂) forms carbon dioxide (CO₂). This balanced equation shows the stoichiometry of the reaction, specifying that two molecules of CO react with one molecule of O₂ to produce two molecules of CO₂. Stoichiometry is not only about balancing elements, but also understanding the ratios and proportions in which chemicals react.

Chemical Reaction Balancing

Chemical reaction balancing is essential for stoichiometry, as it ensures that the law of conservation of mass is obeyed in a given chemical reaction. To balance a chemical equation, one must make sure that the number of atoms for each element is the same on both sides of the equation.

For example, when balancing the reaction of hydrogen and chlorine to form hydrogen chloride, H₂ + Cl₂ → 2HCl, we adjust coefficients to ensure the same number of hydrogen and chlorine atoms are on both sides. Balancing chemical equations often requires trial and error, and understanding the relationship between reactants and products helps to balance complex equations in a methodical way. The completed balanced equation allows us to predict the amount of reactants needed and products formed.

Chemical Formulas

Chemical formulas represent the composition of a substance using atomic symbols and numerical subscripts. They provide information about the type and number of atoms that make up a molecule or compound.

For instance, the chemical formula for sodium nitride is Na₃N, indicating that there are three sodium (Na) atoms for every nitrogen (N) atom in the compound. Understanding chemical formulas is integral when balancing chemical equations since these formulas directly indicate the proportions of the elements involved. They help in visualizing the molecules and in applying the stoichiometry of the reaction, especially in synthesis reactions where new compounds are formed from simpler substances.