Problem 73 - Chemistry: The Central Science

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 a 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.

Step-by-Step Solution

Answer

(a) \(2CH4 + 2NH3 + O2 \rightarrow 2HCN + 3H2O\) (b) \(NaHCO3 + HX \rightarrow NaX + CO2 + H2O\) (c) \(BaCO3 + SO2 \rightarrow BaSO4 + CO2\)

Step 1: Write the unbalanced equation

First, write down the chemical formulas of the reactants and products: methane (CH4), ammonia (NH3), air (contains oxygen, O2), hydrogen cyanide (HCN), and water (H2O). The unbalanced equation is: CH4 + NH3 + O2 → HCN + H2O

Step 2: Balancing the equation

To balance the equation, adjust the coefficients of the reactants and products: 2CH4 + 2NH3 + O2 → 2HCN + 3H2O (b) Reaction of baking soda with an acid

Step 1: Write the general equation

Baking soda (NaHCO3) reacts with an acid (HX, where X is a monovalent anion) to produce a salt (NaX), carbon dioxide (CO2), and water (H2O). The unbalanced equation is: NaHCO3 + HX → NaX + CO2 + H2O

Step 2: Balance the equation

The equation is already balanced, so no adjustments are needed. (c) Reaction of barium carbonate with sulfur dioxide

Step 1: Write the unbalanced equation

First write the chemical formulas of the reactants and products: barium carbonate (BaCO3), sulfur dioxide (SO2), barium sulfate (BaSO4), and carbon dioxide (CO2). The unbalanced equation is: BaCO3 + SO2 → BaSO4 + CO2

Step 2: Balancing the equation

The equation is already balanced, so no adjustments are needed. In conclusion, the balanced equations for the reactions are: (a) 2CH4 + 2NH3 + O2 → 2HCN + 3H2O (b) NaHCO3 + HX → NaX + CO2 + H2O (c) BaCO3 + SO2 → BaSO4 + CO2