Question

Write balanced chemical equations to correspond to each of the following descriptions: (a) When sulfur trioxide gas reacts with water, a solution of sulfuric acid forms. (b) Boron sulfide, \(\mathrm{B}_{2} \mathrm{~S}_{3}(s)\), reacts violently with water to form dissolved boric acid, \(\mathrm{H}_{3} \mathrm{BO}_{3}\), and hydrogen sulfide gas. (c) When an aqueous solution of lead(II) nitrate is mixed with an aqueous solution of sodium iodide, an aqueous solution of sodium nitrate and a yellow solid, lead iodide, are formed. (d) When solid mercury(II) nitrate is heated, it decomposes to form solid mercury(II) oxide, gaseous nitrogen dioxide, and oxygen. (e) Copper metal reacts with hot concentrated sulfuric acid solution to form aqueous copper(II) sulfate, sulfur dioxide gas, and water.

Short answer

(a) \(SO_3 (g) + H_2O (l) \rightarrow H_2SO_4 (aq)\) (b) \(B_2S_3 (s) + 6 H_2O (l) \rightarrow 2 H_3BO_3 (aq) + 3 H_2S (g)\) (c) \(Pb(NO_3)_2 (aq) + 2 NaI (aq) \rightarrow 2 NaNO_3 (aq) + PbI_2 (s)\) (d) \(2 Hg(NO_3)_2 (s) \rightarrow 2 HgO (s) + 4 NO_2 (g) + O_2 (g)\) (e) \(Cu (s) + 2 H_2SO_4 (aq) \rightarrow CuSO_4 (aq) + 2 H_2O (l) + SO_2 (g)\)

Step-by-step solution

Identify reactants and products

In this reaction, the reactants are sulfur trioxide (SO3) gas and water (H2O), while the product is sulfuric acid (H2SO4).

Write and balance the equation

The balanced equation will be: \[SO_3 (g) + H_2O (l) \rightarrow H_2SO_4 (aq)\] (b) Reaction of boron sulfide with water to form dissolved boric acid and hydrogen sulfide gas

Identify reactants and products

In this reaction, the reactants are boron sulfide (B2S3), water (H2O), while the products are dissolved boric acid (H3BO3), and hydrogen sulfide gas (H2S).

Write and balance the equation

The balanced equation will be: \[B_2S_3 (s) + 6 H_2O (l) \rightarrow 2 H_3BO_3 (aq) + 3 H_2S (g)\] (c) Reaction of an aqueous solution of lead(II) nitrate and sodium iodide to form sodium nitrate and lead iodide

Identify reactants and products

In this reaction, the reactants are lead(II) nitrate (Pb(NO3)2) and sodium iodide (NaI), while the products are sodium nitrate (NaNO3) and lead iodide (PbI2).

Write and balance the equation

The balanced equation will be: \[Pb(NO_3)_2 (aq) + 2 NaI (aq) \rightarrow 2 NaNO_3 (aq) + PbI_2 (s)\] (d) Decomposition of solid mercury(II) nitrate to form solid mercury(II) oxide, nitrogen dioxide, and oxygen

Identify reactants and products

In this reaction, the reactant is mercury(II) nitrate (Hg(NO3)2), while the products are mercury(II) oxide (HgO), nitrogen dioxide (NO2), and oxygen (O2).

Write and balance the equation

The balanced equation will be: \[2 Hg(NO_3)_2 (s) \rightarrow 2 HgO (s) + 4 NO_2 (g) + O_2 (g)\] (e) Reaction of copper metal with hot concentrated sulfuric acid to form aqueous copper(II) sulfate, sulfur dioxide gas, and water

Identify reactants and products

In this reaction, the reactants are copper metal (Cu) and sulfuric acid (H2SO4), while the products are copper(II) sulfate (CuSO4), sulfur dioxide gas (SO2), and water (H2O).

Write and balance the equation

The balanced equation will be: \[Cu (s) + 2 H_2SO_4 (aq) \rightarrow CuSO_4 (aq) + 2 H_2O (l) + SO_2 (g)\]

Key concepts

Balancing Equations

Balancing chemical equations is a fundamental skill in chemistry that ensures we respect the law of conservation of mass. This law states that matter is neither created nor destroyed in a chemical reaction, so each element must have the same number of atoms on both sides of the equation. To balance an equation, follow these simple steps:

Identify all the reactants and products in the reaction. Write down their chemical formulas.
Count the number of atoms of each element in both reactants and products.
Adjust coefficients, the numbers in front of the chemical formulas, to balance the atoms on both sides.
Leave compounds containing only one element for last, as adjusting them is easier.
Balancing is achieved when you have equal numbers of each type of atom on both the reactant and product sides. For example, in the reaction forming sulfuric acid from sulfur trioxide and water, the balanced equation is:

\[ SO_3 (g) + H_2O (l) \rightarrow H_2SO_4 (aq) \]
This indicates that one molecule of sulfur trioxide reacts with one molecule of water to produce one molecule of sulfuric acid, illustrating balanced atoms for each element.

Sulfuric Acid Formation

Sulfuric acid is an important compound with numerous industrial applications. It is commonly produced through the reaction between sulfur trioxide gas and water. This process is straightforward and occurs according to the following equation:

\[ SO_3 (g) + H_2O (l) \rightarrow H_2SO_4 (aq) \]
Here, sulfur trioxide (SO_3) is combined with water (H_2O) to form sulfuric acid (H_2SO_4), a strong acid frequently used in fertilizers, battery acid, and various chemical manufacturing processes.

Acids like sulfuric acid play critical roles in chemical reactions because they donate protons (H extsuperscript{+} ions) and accept electrons. Understanding the production of sulfuric acid is vital due to its wide range of applications in industries and its importance in the chemical reactions necessary for those applications.

Lead(II) Nitrate Reaction

Reactions often involve the exchange of ions between two solutes. A classic example is the reaction between lead(II) nitrate and sodium iodide, resulting in the formation of lead iodide and sodium nitrate.

This reaction can be represented by the balanced chemical equation:
\[ Pb(NO_3)_2 (aq) + 2 NaI (aq) \rightarrow 2 NaNO_3 (aq) + PbI_2 (s) \]
Here, the mixing of aqueous lead(II) nitrate and sodium iodide results in the formation of a yellow precipitate, lead iodide (PbI_2), and aqueous sodium nitrate (NaNO_3). This is a precipitation reaction where a solid is formed from two aqueous solutions.

Such reactions are vital in laboratory settings to isolate certain compounds and in various industries for the production or refinement of materials, showcasing the practical application of chemical principles in everyday processes.

Mercury(II) Nitrate Decomposition

The decomposition of mercury(II) nitrate involves breaking down a solid compound when heated, producing new substances. This decomposition can be expressed as follows:

\[ 2 Hg(NO_3)_2 (s) \rightarrow 2 HgO (s) + 4 NO_2 (g) + O_2 (g) \]
In this reaction, mercury(II) nitrate decomposes upon heating to form solid mercury(II) oxide, nitrogen dioxide gas, and oxygen gas. Decomposition reactions involve the breakdown of a compound into simpler compounds or elements. They often require energy, commonly in the form of heat, to occur.

This specific reaction is an example of a thermal decomposition, which is important in processes such as metal extraction and the production of specific chemicals. Understanding these kinds of reactions is crucial for both academic studies in chemistry and practical applications in various manufacturing industries.