Write the K_eq expression for the following acid–base reactions. [You don't need to calculate K_eq here.]
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Verified step by step guidance

1. Step 1: Identify the acid and base on the reactant side. In this reaction, cyclopentanethiol (SH group) acts as the acid, and isopropoxide (-O group) acts as the base.
2. Step 2: Identify the conjugate acid and conjugate base on the product side. Cyclopentanethiolate (S⁻ group) is the conjugate base, and isopropanol (HO group) is the conjugate acid.
3. Step 3: Write the equilibrium constant expression (Keq) for the acid-base reaction. Keq is defined as the ratio of the concentrations of the products to the concentrations of the reactants.
4. Step 4: Use the chemical species to construct the Keq expression. The general form is: Keq = [Products]/[Reactants]. For this reaction, Keq = ([Cyclopentanethiolate] × [Isopropanol]) / ([Cyclopentanethiol] × [Isopropoxide]).
5. Step 5: Ensure that the expression includes only the species involved in the equilibrium and that it reflects the stoichiometry of the reaction. Double-check that the charges and chemical formulas are correctly represented.

Key Concepts

Equilibrium Constant (K_eq)

The equilibrium constant (K_eq) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given chemical reaction. It is derived from the law of mass action and is specific to a particular reaction at a given temperature. For acid-base reactions, K_eq can indicate the strength of the acids and bases involved.

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H⁺ ions) between reactants. In these reactions, acids donate protons while bases accept them. Understanding the nature of the acids and bases involved is crucial for writing the correct K_eq expression, as it determines the direction of the equilibrium and the species present at equilibrium.

Writing K_eq Expressions

To write the K_eq expression for an acid-base reaction, one must identify the products and reactants and express the equilibrium constant as the ratio of the concentrations of the products raised to their stoichiometric coefficients over the concentrations of the reactants raised to their coefficients. This process requires careful attention to the balanced chemical equation and the states of the compounds involved.