1. The problem is to understand the significance of the chemical equation: $\mathrm{MgCO_3 + 2HCl \rightarrow MgCl_2 + CO_2 + H_2O}$.\n\n2. This equation represents a chemical reaction where magnesium carbonate ($\mathrm{MgCO_3}$) reacts with hydrochloric acid ($\mathrm{HCl}$).\n\n3. The reaction produces magnesium chloride ($\mathrm{MgCl_2}$), carbon dioxide ($\mathrm{CO_2}$), and water ($\mathrm{H_2O}$).\n\n4. This is an example of an acid-carbonate reaction, which typically produces a salt, carbon dioxide gas, and water.\n\n5. The significance is that it demonstrates how carbonates react with acids to release $\mathrm{CO_2}$ gas, which can be observed as bubbling or fizzing.\n\n6. This reaction is important in various applications such as acid-base chemistry, geology (weathering of rocks), and industrial processes.