8 of 10 Next A lab group reacts sodium oxide \( \left(\mathrm{Na}_{2} \mathrm{O}\right) \) with hydrochloric acid \( (\mathrm{HCl}) \) to produce sodium chloride \( (\mathrm{NaCl}) \) and water \( \left(\mathrm{H}_{2} \mathrm{O}\right) \). When writing their lab repor they came up with the following equation to represent the reaction: \[ \mathrm{Na}_{2} \mathrm{O}+\mathrm{HCl} \rightarrow \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{O} \] Does this equation satisfy the Law of Conservation of Matter? Why or why not? A Yes, since there are 5 reactant atoms and 5 product atoms. B Yes, since there is a subscript of 2 on both sides on the equation. C No, since there are two sodium atoms as reactants, but only one sodium atom as a product. D No, since there is a liquid and a solid as reactants, but a gas and a solid as a product.

The equation presented by the lab group does not satisfy the Law of Conservation of Matter. The correct stoichiometry must account for all atoms on both sides of the equation. In this case, one sodium oxide molecule contains two sodium atoms, while the resulting compounds only have one sodium atom in the products. Therefore, option C accurately identifies the discrepancy: there are two sodium atoms as reactants but only one as a product, violating the conservation principle. To balance the chemical equation and satisfy the Law of Conservation of Matter, the lab group should adjust it to show that two molecules of hydrochloric acid react with one molecule of sodium oxide. The balanced equation would be: \[ \mathrm{Na}_{2} \mathrm{O} + 2\mathrm{HCl} \rightarrow 2\mathrm{NaCl} + \mathrm{H}_{2} \mathrm{O} \] This ensures that there are equal numbers of each type of atom on both sides, highlighting the importance of proper stoichiometry in chemical reactions!