12.80 Which of the following compounds, if either, will dissolve in \(1.00 \mathrm{M} \mathrm{HNO}_{3}(\mathrm{aq})\) : (a) \(\mathrm{Bi}_{2} \mathrm{~S}_{3}\) (s); (b) \(\mathrm{FeS}(\mathrm{s})\) ? Substantiate your answer by giving an appropriate calculation.

Understanding the concept of solubility rules is critical when predicting whether a substance will dissolve in a solution. Solubility rules are guidelines that help us predict which ionic compounds are soluble or insoluble in water.

For instance, nitrates (NO3-) and most alkali metal compounds are generally soluble. Conversely, sulfides (S2-), hydroxides (OH-), and carbonates (CO3 2-) are typically insoluble, with some exceptions. However, the presence of a strong acid like nitric acid (HNO3) can change the solubility of a substance. In the context of our exercise, the strong acid can cause typically insoluble sulfides to react and dissolve.

Through these rules, we determine that in water, bismuth sulfide (Bi2S3) and iron(II) sulfide (FeS) are generally not soluble. If you're faced with a solubility question, start by referencing these rules; they are the first step to unlocking the puzzle of whether a reaction will proceed or a compound will dissolve.

Acid-base reactions are a category of chemical reactions where an acid and a base react. This type of reaction commonly results in the formation of water and a salt. Strong acids, such as HNO3, can facilitate reactions that would not ordinarily occur in a neutral environment.

In the given problem, when the strong acid HNO3 is introduced to bisulfide (Bi2S3) and iron(II) sulfide (FeS), which are bases, a chemical reaction ensues. This reaction typically leads to the formation of a salt and possibly the liberation of a gas, often changing the solubility of the original compound significantly. HNO3, for instance, will react with the metallic sulfides to produce their soluble nitrates, water, and gaseous by-products like hydrogen sulfide (H2S) or sulfur dioxide (SO2), thus exemplifying an acid-base reaction that alters solubility.

To understand whether a chemical reaction is feasible, or likely to occur, you'll want to consider several factors. Reaction feasibility is often evaluated in terms of thermodynamics, which looks at the energy changes, and kinetics, which considers the speed of the reaction.

Products that are gases or are highly soluble tend to make the reaction more favorable because their formation helps pull the reaction forward. In the given exercise, the formation of gas (such as H2S or SO2) along with soluble nitrates suggests that the reaction is feasible—gases escape from the solution, and the soluble products mean the reactants are continuously consumed. Therefore, when evaluating reaction feasibility, always consider the physical state of the products (solid, liquid, gas) and their solubility. This understanding of reaction feasibility can give us confidence in predicting not just if, but to what extent, a reaction may occur in a given set of conditions.

Chemical equations are symbolic representations of chemical reactions, with reactants on the left, products on the right, and an arrow pointing from reactants to products to indicate the direction of the reaction. Balanced chemical equations show the conservation of mass; each element has the same number of atoms on both sides of the equation.

In our exercise, writing balanced chemical equations for the reactions between Bi2S3 or FeS and HNO3 allows us to visualize the reactants' transformation into products. Balancing these equations is essential to determine the stoichiometry, or relative proportions, of each substance involved in the reaction. This is crucial for calculating how much of the original compound will dissolve in the acid solution. Chemical equations are the language of chemistry; they allow us to communicate what is happening in a reaction succinctly and accurately.