Problem 70 - Chemistry: The Central Science

Question

Write a balanced equation for each of the following reactions: (a) Burning magnesium metal in a carbon dioxide atmosphere reduces the \(\mathrm{CO}_{2}\) to carbon. (b) In photosynthesis, solar energy is used to produce glucose \(\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)\) and \(\mathrm{O}_{2}\) from carbon dioxide and water. (c) When carbonate salts dissolve in water, they produce basic solutions.

Step-by-Step Solution

Answer

(a) Mg + CO₂ → 2MgO + C (b) 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ (c) Na₂CO₃ + H₂O → 2NaOH + H₂CO₃

Step 1: Write the unbalanced equation

To write an unbalanced equation, we list the reactants and products involved in the reaction. For this reaction, we have magnesium metal (Mg) reacting with carbon dioxide (CO₂) to form magnesium oxide (MgO) and carbon (C). Unbalanced equation: Mg + CO₂ → MgO + C

Step 2: Balance the equation

To balance the equation, we compare the number of atoms of each element on both sides and adjust the coefficients accordingly. Here, we have one oxygen on the product side and two oxygens on the reactant side, so we need to add a coefficient of 2 in front of MgO. Balanced equation: Mg + CO₂ → 2MgO + C #b) Photosynthesis reaction#

Step 1: Write the unbalanced equation

In the photosynthesis reaction, carbon dioxide (CO₂) reacts with water (H₂O) to form glucose (C₆H₁₂O₆) and oxygen gas (O₂). Unbalanced equation: CO₂ + H₂O → C₆H₁₂O₆ + O₂

Step 2: Balance the equation

To balance the equation, we adjust the coefficients of each part accordingly to have the same number of atoms of each element on both sides. Balanced equation: 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ #c) Carbonate salts dissolving in water#

Step 1: Write the unbalanced equation

When carbonate salts (such as sodium carbonate, Na₂CO₃) dissolve in water (H₂O), they produce a basic solution (such as sodium hydroxide, NaOH) and carbonic acid (H₂CO₃). Unbalanced equation: Na₂CO₃ + H₂O → NaOH + H₂CO₃

Step 2: Balance the equation

To balance the equation, we adjust the coefficients of each part accordingly. Balanced equation: Na₂CO₃ + H₂O → 2NaOH + H₂CO₃