Question

Acid rain can damage marble statues and limestone building materials. Write a balanced chemical equation using an acid of your choice.

Short answer

The balanced equation is: H₂SO₄ + CaCO₃ → H₂O + CO₂ + CaSO₄.

Step-by-step solution

Choose an Acid

Select an acid that is commonly associated with acid rain. A typical example is sulfuric acid (H₂SO₄), which is a major component of acid rain and reacts with calcium carbonate in marble and limestone.

Identify the Reaction Components

The acid will react with calcium carbonate (CaCO₃), the primary component of marble and limestone. The reaction will produce water (H₂O), carbon dioxide (CO₂), and a salt in the form of calcium sulfate (CaSO₄).

Write the Unbalanced Equation

Combine the components into an unbalanced chemical equation: H₂SO₄ + CaCO₃ → H₂O + CO₂ + CaSO₄.

Balance the Chemical Equation

Ensure the same number of each type of atom on both sides of the equation. The balanced equation is: H₂SO₄ + CaCO₃ → H₂O + CO₂ + CaSO₄. In this case, the equation is already balanced, as each element has the same number of atoms on both sides of the equation.

Key concepts

Understanding Chemical Equations

A chemical equation is a symbolic representation of a chemical reaction. In these equations, the substances that interact are called reactants and the substances formed are termed products. When writing a chemical equation, we use chemical formulas to depict these substances and an arrow to show the direction of the reaction.
These equations are fundamental because they help us understand what reactions occur and what products to expect. Take, for instance, the reaction between sulfuric acid and calcium carbonate. This is an essential reaction in understanding the effects of acid rain on limestone structures. The chemical equation here indicates the transformation of reactants into products, offering insight into the process and results of the reaction.

The Role of Sulfuric Acid

Sulfuric acid, with the formula \( \text{H}_2\text{SO}_4 \), is a highly corrosive strong acid. It is one of the primary acids found in acid rain, owing to industrial emissions. When sulfur dioxide (SO₂) from industrial activities combines with water vapor in the atmosphere, it forms sulfuric acid.
Acid rain containing sulfuric acid can lead to severe damage to natural and man-made structures. Particularly, it reacts aggressively with calcium carbonate, a principal component of marble and limestone. This reaction underscores why sulfuric acid is crucial in understanding the degradation processes of stone monuments and buildings exposed regularly to acid rain.

All About Calcium Carbonate

Calcium carbonate, \( \text{CaCO}_3 \), is a common substance found in rocks as minerals like calcite and aragonite. It's a principal component of marble and limestone. Known for its wide use in building materials, calcium carbonate is attractive for its strength and durability.
However, its reaction with acids like sulfuric acid turns this asset into a vulnerability. The reaction results in products like calcium sulfate, carbon dioxide, and water. This chemical process can erode the surfaces of buildings and statues, causing them to deteriorate over time, revealing the environmental impact of calcium carbonate under acidic conditions.

Balancing Chemical Equations

Balancing chemical equations is a crucial skill in chemistry that ensures the conservation of mass in a reaction. In any chemical equation, the number of atoms for each element must be the same on both the reactant and product sides.
For instance, in the reaction between sulfuric acid and calcium carbonate, the equation \( \text{H}_2\text{SO}_4 + \text{CaCO}_3 \rightarrow \text{H}_2\text{O} + \text{CO}_2 + \text{CaSO}_4 \) is already balanced as shown. Each type of atom appears in equal numbers on both sides of the equation. This balance confirms that matter is neither created nor destroyed, adhering to the law of conservation of mass, which is pivotal in chemical studies and practical applications.