One harmful effect of acid rain is the deterioration of structures and statues made of marble or limestone, both of which are essentially calcium carbonate. The reaction of calcium carbonate with sulfuric acid yields carbon dioxide, water, and calcium sulfate. Because calcium sulfate is marginally soluble in water, part of the object is washed away by the rain. Write a balanced chemical equation for the reaction of sulfuric acid with calcium carbonate.

The given reactants are sulfuric acid (H₂SO₄) and calcium carbonate (CaCO₃). When these react, they produce carbon dioxide (CO₂), water (H₂O), and calcium sulfate (CaSO₄).

Having the formulae of the reactants and the products, we write them in the correct order of a chemical equation. Reactants are always on the left (LHS) and the products on the right (RHS): \( \text{H}_2\text{SO}_4 + \text{CaCO}_3 \rightarrow \text{CO}_2 + \text{H}_2\text{O}+ \text{CaSO}_4 \)

On first look, there are 2 oxygen atoms on LHS in the compound CaCO₃ and 5 on the RHS. To balance the equation, we need to make sure the numbers of each type of atom on both sides of the equation are equal. The easiest way to do this is to adjust the coefficients (the numbers in front of atoms or compounds). First, balance the calcium atoms by putting a 1 in front of CaCO₃ and CaSO₄. Next, balance the sulfur atoms by also putting a 1 in front of H₂SO₄ and CaSO₄. For the carbon atoms, put a 1 in front of CaCO₃ and CO₂. To balance the hydrogen and oxygen atoms, put a 2 in front of H₂O. Now, recheck the balance of the oxygen atoms. If it is not balanced, adjust the number appropriately. After balancing atoms of each element, the balanced equation is: \( \text{H}_2\text{SO}_4 + \text{CaCO}_3 \rightarrow \text{CO}_2 + \text{H}_2\text{O}+ \text{CaSO}_4 \) This means that one molecule of sulfuric acid reacts with one molecule of calcium carbonate to produce one molecule of carbon dioxide, one molecule of water and one molecule of calcium sulfate. Since no other adjustments are needed, this is the balanced equation for the reaction.