Write a balanced chemical equation showing how each metal oxide reacts with HCl. (a) \(\mathrm{SrO}\) (b) \(\mathrm{Na}_{2} \mathrm{O}\) (c) \(\mathrm{Li}_{2} \mathrm{O}\) (d) \(\mathrm{BaO}\)

Chemical reactions are processes where substances, known as reactants, transform into new substances called products. This transformation occurs due to the breaking and forming of chemical bonds. The reactions are governed by several laws, with one of the most important being the Law of Conservation of Mass, which states that mass cannot be created or destroyed in an ordinary chemical reaction.

The reactants we see in common acid-metal oxide reactions, such as the reaction between metal oxides and hydrochloric acid (HCl), fall under the category of double displacement reactions. In each case, the metal oxide acts as a base that neutralizes the acid HCl, producing a salt and water. For example, with strontium oxide (SrO) reacting with HCl, the strontium (Sr) switches places with the hydrogen (H) to create strontium chloride (SrCl2) and water (H2O). When writing chemical equations, ensuring they are balanced is crucial - the same number of each type of atom must exist on both sides of the equation.

An acid-base reaction is a type of chemical reaction that involves the transfer of protons (H+ ions) from an acid to a base. In the context of our example, hydrochloric acid (HCl) donates protons to the metal oxide base.

Acid-base reactions invariably produce salt and water, as showcased by the several reactions provided. For instance, when sodium oxide (Na2O) reacts with hydrochloric acid, the result is sodium chloride (NaCl) and water (H2O). Understanding these reactions is pivotal in many fields like chemistry, biology, and environmental science, as they are fundamental to processes such as digestion, industrial manufacturing, and in regulating the pH of natural and man-made environments. Each reaction follows the pattern of the acid providing protons to the base, resulting in a neutralization process that forms neutral products.

Stoichiometry is the aspect of chemistry that relates to the quantitative relationships between reactants and products in chemical reactions. It is a crucial concept for ensuring balanced chemical equations.

The stoichiometry of a given reaction involves calculations based on the mole concept — the idea that substances react in fixed ratios of moles. To balance a chemical equation, like for the reaction of barium oxide (BaO) with HCl, one must ensure that the number of moles of each element is the same on both sides of the equation. In essence, stoichiometry ensures that you are accounting for all atoms involved in the reaction, adhering to the Law of Conservation of Mass. The balanced equations provided in the exercise solutions illustrate stoichiometry's application, with precise mole ratios illustrating how each reactant combines to form products quantitatively.