Question

Write a balanced equation for each of the following reactions: (a) Hydrogen cyanide is formed commercially by passing a mixture of methane, ammonia, and air over catalyst at \(800^{\circ} \mathrm{C} .\) Water is a by-product of the reaction. (b) Baking soda reacts with acids to produce carbon dioxide gas. (c) When barium carbonate reacts in air with sulfur dioxide, barium sulfate and carbon dioxide form.

Short answer

The balanced equations for the given reactions are as follows: (a) 2CH4(g) + 2NH3(g) + 3O2(g) → 2HCN(g) + 6H2O(g) (b) NaHCO3(s) + HX(aq) → NaX(aq) + CO2(g) + H2O(l) (c) BaCO3(s) + SO2(g) → BaSO4(s) + CO2(g)

Step-by-step solution

Reaction (a): Formation of hydrogen cyanide

The formation of hydrogen cyanide can be represented by the following equation: CH4(g) + NH3(g) + O2(g) → HCN(g) + H2O(g) Now, we need to balance this equation. The balanced equation is: 2CH4(g) + 2NH3(g) + 3O2(g) → 2HCN(g) + 6H2O(g)

Reaction (b): Baking soda reacting with an acid

Since no specific acid is mentioned, let's assume it reacts with a generic acid, HX, where X represents the anion of the acid. Baking soda reacts with acid to produce carbon dioxide gas, sodium salt, and water. The equation is: NaHCO3(s) + HX(aq) → NaX(aq) + CO2(g) + H2O(l) This equation is already balanced.

Reaction (c): Barium carbonate reacting with sulfur dioxide

The reaction between barium carbonate and sulfur dioxide can be represented by the following equation: BaCO3(s) + SO2(g) → BaSO4(s) + CO2(g) This equation is also already balanced.

Key concepts

Balancing Chemical Equations

Balancing chemical equations is an essential skill in chemistry. It's about ensuring that the number of atoms of each element is the same on both sides of the equation. This reflects the Law of Conservation of Mass, which states that matter cannot be created or destroyed. To balance an equation, we adjust the coefficients (the numbers before molecules) without changing the molecular formulas themselves.
For example, if one nitrogen atom reacts to become two separate nitrogen-containing compounds, we must make sure that there are two nitrogen atoms on both sides of the equation.

• Count the number of each type of atom on both sides.
• Adjust coefficients to equalize the number of atoms for each element.
• Recheck the balance after every adjustment.

This process ensures a balanced equation, which is critical for accurately representing chemical reactions.

Hydrogen Cyanide Production

Hydrogen cyanide (HCN) production is a process used in various industrial applications. It's often produced commercially by a high-temperature reaction involving methane (\( ext{CH}_4\)), ammonia (\( ext{NH}_3\)), and oxygen (\( ext{O}_2\)), typically over a catalyst at around 800°C. This process results in the formation of hydrogen cyanide along with water as a by-product.
Here's the balanced equation for hydrogen cyanide production:

• Reactants: \(2 ext{CH}_4(g) + 2 ext{NH}_3(g) + 3 ext{O}_2(g)\)
• Products: \(2 ext{HCN}(g) + 6 ext{H}_2 ext{O}(g)\)

In this reaction, we've balanced the equation by ensuring that each reactant and product side has the same number of each type of atom. This balance is crucial for the stoichiometry of the reaction, ensuring optimal production efficiency.

Baking Soda Reactions

Baking soda, known chemically as sodium bicarbonate (\( ext{NaHCO}_3\)), reacts with acids to release carbon dioxide gas, commonly observed in baking and science experiments. When baking soda encounters an acid, it decomposes, releasing gas and creating a fizzing effect.
The reaction can be simplified with a general acid denoted as \( ext{HX}\), which results in the formation of water, carbon dioxide, and a sodium salt:

• Equation: \( ext{NaHCO}_3(s) + ext{HX}(aq) ightarrow ext{NaX}(aq) + ext{CO}_2(g) + ext{H}_2 ext{O}(l)\)

Each component is essential: \( ext{CO}_2\) offers leavening in baking, while the sodium salt remains in solution. This reaction showcases an acid-base interaction that is balanced from the start, illustrating a classic decomposition reaction.

Sulfur Dioxide Reactions

Sulfur dioxide (\( ext{SO}_2\)) is a significant compound in environmental chemistry, often emerging from processes like combustion. In the presence of barium carbonate (\( ext{BaCO}_3\)), a reaction occurs that results in barium sulfate (\( ext{BaSO}_4\)) and carbon dioxide (\( ext{CO}_2\)).
Here's the balanced equation representing the process:

• Reactants: \( ext{BaCO}_3(s) + ext{SO}_2(g)\)
• Products: \( ext{BaSO}_4(s) + ext{CO}_2(g)\)

This reaction highlights the transformation of sulfur dioxide into a harmless sulfate compound, a fundamental approach in pollutant management. Balancing such reactions is integral for reducing environmental impact and understanding natural processes.