Problem 69 - 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) \( 2CH_4 + 2 NH_3 + 3 O_2 \rightarrow 2 HCN + 6 H_2O \) (b) \( NaHCO_3 + HCl \rightarrow NaCl + CO_2 + H_2O \) (c) \( BaCO_3 + SO_2 \rightarrow BaSO_4 + CO_2 \)

Step 1: Write the unbalanced equation

First, we will write the unbalanced chemical equation for the reaction using the given information: \( CH_4 + NH_3 + O_2 \rightarrow HCN + H_2O \)

Step 2: Balance the equation

Now, we will balance the chemical equation by adjusting the coefficients of the reactants and products. Balance the elements in the following order: C, H, N, and O. \[ 2CH_4 + 2 NH_3 + 3 O_2 \rightarrow 2 HCN + 6 H_2O \] The balanced equation for the formation of hydrogen cyanide is: \( 2CH_4 + 2 NH_3 + 3 O_2 \rightarrow 2 HCN + 6 H_2O \) (b) Reaction between baking soda and an acid:

Step 1: Write the unbalanced equation

First, we will write the unbalanced chemical equation for the reaction using the given information. Baking soda is sodium bicarbonate (NaHCO3) and a common acid is hydrochloric acid (HCl). The products are sodium chloride (NaCl), carbon dioxide (CO2), and water (H2O). \( NaHCO_3 + HCl \rightarrow NaCl + CO_2 + H_2O \)

Step 2: Balance the equation

This equation is already balanced as written. All elements have the same number of atoms on both sides of the equation. The balanced equation for the reaction between baking soda and an acid is: \( NaHCO_3 + HCl \rightarrow NaCl + CO_2 + H_2O \) (c) Reaction of barium carbonate with sulfur dioxide:

Step 1: Write the unbalanced equation

First, we will write the unbalanced chemical equation for the reaction using the given information. Barium carbonate is BaCO3 and sulfur dioxide is SO2. The products are barium sulfate (BaSO4) and carbon dioxide (CO2). \( BaCO_3 + SO_2 \rightarrow BaSO_4 + CO_2 \)

Step 2: Balance the equation

This equation is already balanced as written. All elements have the same number of atoms on both sides of the equation. The balanced equation for the reaction of barium carbonate with sulfur dioxide is: \( BaCO_3 + SO_2 \rightarrow BaSO_4 + CO_2 \)