Question

Write all the mole-to-mole conversion factors that can be written based on the following chemical formulas: (a) \(\mathrm{SO}_{2}\), (b) \(\mathrm{As}_{2} \mathrm{O}_{3}\) (c) \(\mathrm{K}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{Na}_{2} \mathrm{HPO}_{4}\)

Short answer

\(\mathrm{SO}_{2}\): \frac{1 \text{ mol S}}{2 \text{ mol O}}, \frac{2 \text{ mol O}}{1 \text{ mol S}}. \mathrm{As}_{2} \mathrm{O}_{3}: \frac{2 \text{ mol As}}{3 \text{ mol O}}, \frac{3 \text{ mol O}}{2 \text{ mol As}}. \mathrm{K}_{2} \mathrm{SO}_{4}: \frac{2 \text{ mol K}}{1 \text{ mol \mathrm{SO}_{4}}}, \frac{1 \text{ mol \mathrm{SO}_{4}}}{2 \text{ mol K}}. \mathrm{Na}_{2} \mathrm{HPO}_{4}: \frac{2 \text{ mol Na}}{1 \text{ mol \mathrm{HPO}_{4}}}, \frac{1 \text{ mol \mathrm{HPO}_{4}}}{2 \text{ mol Na}}.

Step-by-step solution

Introduction to Mole-to-Mole Conversion Factors

Mole-to-mole conversion factors are derived from the coefficients used in balanced chemical equations. They indicate the ratio of moles of reactants and products involved in the reaction. In the absence of a given chemical reaction, we assume a hypothetical 1:1 stoichiometry for conversion between moles of different elements within a compound. This step-by-step solution will focus on deriving such conversion factors based on the subscripts in each chemical formula.

Analyze the Chemical Formula of \(\mathrm{SO}_{2}\)

For sulfur dioxide (\(\mathrm{SO}_{2}\)), the subscripts indicate that 1 mole of sulfur (S) reacts with 2 moles of oxygen (O) atoms. The mole-to-mole conversion factors are: \[\frac{1 \text{ mol S}}{2 \text{ mol O}} \quad \text{and} \quad \frac{2 \text{ mol O}}{1 \text{ mol}\quad S}\]

Analyze the Chemical Formula of \(\mathrm{As}_{2} \mathrm{O}_{3}\)

For arsenic(III) oxide (\(\mathrm{As}_{2} \mathrm{O}_{3}\)), the subscripts indicate that 2 moles of arsenic (As) react with 3 moles of oxygen (O) atoms. The mole-to-mole conversion factors are: \[\frac{2 \text{ mol As}}{3 \text{ mol O}} \quad \text{and} \quad \frac{3 \text{ mol O}}{2 \text{ mol As}}\]

Analyze the Chemical Formula of \(\mathrm{K}_{2} \mathrm{SO}_{4}\)

For potassium sulfate (\(\mathrm{K}_{2} \mathrm{SO}_{4}\)), the subscripts indicate that 2 moles of potassium (K) react with 1 mole of sulfate (\(\mathrm{SO}_{4}\)). The mole-to-mole conversion factors are: \[\frac{2 \text{ mol K}}{1 \text{ mol \mathrm{SO}_{4}}} \quad \text{and} \quad \frac{1 \text{ mol \mathrm{SO}_{4}}}{2 \text{ mol K}}\]

Analyze the Chemical Formula of \(\mathrm{Na}_{2} \mathrm{HPO}_{4}\)

For sodium hydrogen phosphate (\(\mathrm{Na}_{2} \mathrm{HPO}_{4}\)), the subscripts show that 2 moles of sodium (Na) react with 1 mole of hydrogen phosphate (\(\mathrm{HPO}_{4}\)). The mole-to-mole conversion factors are: \[\frac{2 \text{ mol Na}}{1 \text{ mol \mathrm{HPO}_{4}}} \quad \text{and} \quad \frac{1 \text{ mol \mathrm{HPO}_{4}}}{2 \text{ mol Na}}\]

Key concepts

Stoichiometry

Stoichiometry is the mathematical relationship between the amounts of reactants and products in a chemical reaction. It is derived from the Greek words 'stoicheion' (element) and 'metron' (measure), and it allows chemists to predict the outcomes of chemical reactions and to quantify the amounts of substances required or produced.

To perform stoichiometry calculations, one must understand the mole concept and be able to convert between masses and moles using molar masses. From there, stoichiometry uses the coefficients from balanced chemical equations to provide mole-to-mole conversion factors. For our purposes, where no reaction is given, we consider the subscripts in the chemical formulas, assuming each entity within the compound is in a 1:1 ratio with itself, thus providing a direct conversion between elements in a given formula.

Chemical Formulas

Chemical formulas represent the types and numbers of atoms in a molecule of a compound. They are essential tools for understanding the composition of substances. The subscripts in chemical formulas show the ratio of atoms of each element present in the compound.

For instance, in the chemical formula \( \mathrm{K}_{2} \mathrm{SO}_{4} \), the subscript '2' after potassium (K) indicates that there are two potassium atoms for every one sulfate group (\( \mathrm{SO}_{4} \)) in the molecule. By exploring the ratios indicated by these subscripts, one can calculate mole-to-mole conversion factors, even when the compound does not participate in a chemical reaction, which is crucial for understanding how elements combine in defined proportions.

Balanced Chemical Equations

Balanced chemical equations provide a snapshot of a chemical reaction, with reactants on the left, products on the right, and coefficients used to ensure that the number of atoms of each element is conserved during the reaction. These coefficients form the basis for mole-to-mole conversion factors in stoichiometry.

For example, if a balanced chemical equation reads \( 2\mathrm{H}_{2} + \mathrm{O}_{2} \rightarrow 2\mathrm{H}_{2}\mathrm{O} \), it tells us that 2 moles of hydrogen gas (\( \mathrm{H}_{2} \) react with 1 mole of oxygen gas (\( \mathrm{O}_{2} \) to produce 2 moles of water (\( \mathrm{H}_{2}\mathrm{O} \)). The coefficients (2, 1, and 2) enable the determination of mole ratios, such as \( \frac{2 \text{ moles } \mathrm{H}_{2}}{1 \text{ mole } \mathrm{O}_{2}} \) or \( \frac{2 \text{ moles } \mathrm{H}_{2}\mathrm{O}}{2 \text{ moles } \mathrm{H}_{2}} \), which are essential when performing calculations related to the reaction.

Chemical Reactions

Chemical reactions are processes where reactants are transformed into products through breaking and forming of chemical bonds. Understanding chemical reactions involves recognizing the reactants and products, predicting the types of reactions, and balancing the equations that represent the reactions.

Various types of reactions exist, including synthesis, decomposition, single replacement, double replacement, and combustion. Each type has its unique pattern of reactant and product formation, and therefore, distinct stoichiometry. While mole-to-mole conversion factors are commonly derived from these reactions, for substances by themselves, we refer to the inherent mole ratios within their chemical formulas to establish the conversions, which offer foundational insights into the quantitative aspects of the substances participating in these reactions.