Question

Write complete ionic and net ionic equations for the reaction between sulfuric acid \(\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)\) and calcium carbonate \(\left(\mathrm{CaCO}_{3}\right)\). $$\mathrm{H}_{2} \mathrm{SO}_{4}(\mathrm{aq})+\mathrm{CaCO}_{3}(\mathrm{s}) \rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{g})+\mathrm{CaSO}_{4}(\mathrm{aq})$$

Short answer

The net ionic equation for the reaction between sulfuric acid and calcium carbonate is: \(\mathrm{2H^{+}(aq) + CaCO_{3}(s) \rightarrow 2H_{2}O(l) + CO_{2}(g) + Ca^{2+}(aq)}\)

Step-by-step solution

Identify ionic species

Sulfuric acid (H₂SO₄) is a strong acid, which means it will dissociate completely in water. Calcium carbonate (CaCO₃) is a solid compound and will not dissociate. In the products, water (H₂O) is a liquid and carbon dioxide (CO₂) is a gas, and neither will dissociate. Calcium sulfate (CaSO₄) is soluble in water, meaning it will dissociate into its ions.

Write the complete ionic equation

Now, we break the compounds into their constituent ions. Remember, only the soluble ionic compounds can dissociate. The complete ionic equation is given by: \(\mathrm{2H^{+}(aq) + SO_{4}^{-2}(aq) + CaCO_{3}(s) \rightarrow 2H_{2}O(l) + CO_{2}(g) + Ca^{2+}(aq) + SO_{4}^{-2}(aq)}\)

Cancel out spectator ions

A spectator ion is an ion that exists in both the reactant and product side of the ionic equation. In this case, SO₄²⁻ is the spectator ion. We can remove it from both sides to write the net ionic equation: \(\mathrm{2H^{+}(aq) + CaCO_{3}(s) \rightarrow 2H_{2}O(l) + CO_{2}(g) + Ca^{2+}(aq)}\)

Net Ionic Equation

Now we have the net ionic equation for the reaction between sulfuric acid and calcium carbonate: \(\mathrm{2H^{+}(aq) + CaCO_{3}(s) \rightarrow 2H_{2}O(l) + CO_{2}(g) + Ca^{2+}(aq)}\) This equation represents the reaction between sulfuric acid and calcium carbonate, showing only the species that actually participate in the reaction.

Key concepts

Chemical Reactions

Chemical reactions are processes in which substances, known as reactants, transform into different substances called products. This change usually involves the breaking and forming of chemical bonds within molecules. Consider, for instance, the reaction between sulfuric acid \(\mathrm{H}_{2}SO_{4}\) and calcium carbonate \(\mathrm{CaCO}_{3}\), a classic example of an acid-carbonate reaction.

The whole process can be broken down into a sequence of events: initially, the acid reacts with the solid carbonate, leading to the production of water \(\mathrm{H}_{2}O\), carbon dioxide \(\mathrm{CO}_{2}\), and calcium sulfate \(\mathrm{CaSO}_{4}\). This type of reaction not only showcases the transformation of reactants into products but also highlights the dynamic nature of chemical reactions where new substances are synthesized, and distinct phases of matter—liquid and gas in this case—are often produced.

Ionic Equations

When dissolving in water, some compounds break down into ions, a process we describe with ionic equations. These equations provide a more detailed view by showcasing the actual ionic species that participate in the reaction. Like in the case of sulfuric acid and calcium carbonate, where sulfuric acid dissociates into hydrogen ions \(\mathrm{H^{+}}\) and sulfate ions \(\mathrm{SO_{4}^{2-}}\), while calcium sulfate dissociates into calcium \(\mathrm{Ca^{2+}}\) and sulfate ions.

Complete Ionic Equation

The complete ionic equation hence disassembles soluble ionic compounds into their respective ions and retains insoluble compounds, liquids, and gases in their molecular form. Here's a closer examination: despite calcium carbonate being a compound, it does not dissociate because it's insoluble as a solid. Thus, in the complete ionic equation, it stays as \(\mathrm{CaCO_{3}(s)}\). Conversely, soluble ionic substances like \(\mathrm{H_{2}SO_{4}}\) and \(\mathrm{CaSO_{4}}\) are represented by their dissociated ions.

Spectator Ions

In the arena of ionic reactions, not all ions engage in the chemical change. Spectator ions are like onlookers at a sporting event; they're present but do not take part in the action. A spectator ion appears unaltered on both the reactant and product sides of our ionic equation.

For instance, the sulfate ion \(\mathrm{SO_{4}^{2-}}\) is present in both reactants and products in the reaction between sulfuric acid and calcium carbonate. Subsequently, it doesn't undergo any change and thus is considered a spectator ion.

Net Ionic Equation

To focus on the species actively involved in the reaction—we eliminate these bystander ions to craft the net ionic equation. This trimmed-down version communicates the essence of the chemical reaction more concisely. By canceling out the spectator ions, in this case, the sulfate ions that occur on both sides, we get the net ionic equation that only includes the reacting ions and the resulting products.