The dissociation constant of formic acid is \(0.00024\). The hydrogen ion concentration in \(0.002 \mathrm{M}-\mathrm{HCOOH}\) solution is nearly (a) \(6.93 \times 10^{-4} \mathrm{M}\) (b) \(4.8 \times 10^{-7} \mathrm{M}\) (c) \(5.8 \times 10^{-4} \mathrm{M}\) (d) \(1.4 \times 10^{-4} \mathrm{M}\)

In the context of chemical reactions, understanding the concept of chemical equilibrium is crucial. It's a state where the rate of the forward reaction equals the rate of the reverse reaction, which means that the concentrations of reactants and products remain constant over time. But this doesn't mean that the reaction has stopped; both reactions are still occurring but at the same rate. Consider a seesaw perfectly balanced with equal weights on both sides: neither side is heavier, and that's the essence of chemical equilibrium.

Every reversible chemical reaction can reach such equilibrium, and it is described quantitatively by the equilibrium constant. For the dissociation of an acid, we have a specific type of equilibrium constant known as the dissociation constant, or Ka. The smaller the Ka value, the weaker the acid and the less it dissociates at equilibrium. Understanding this concept aids in predicting how the reaction proceeds and how to calculate the concentrations of different species in a solution at equilibrium.

The ICE table method is a powerful tool for solving equilibrium problems. The acronym ICE stands for Initial, Change, and Equilibrium, reflecting the three stages of the reaction explored in the table. Initially, you have the concentrations of the reactants and products before the reaction starts. The Change section represents the amount by which each concentration will change as the reaction moves toward equilibrium. Finally, the Equilibrium section shows the concentrations when the reaction is at equilibrium.

The ICE table simplifies equilibrium calculations by clearly organizing data and providing a visual framework for understanding the changes that occur in a chemical system. By setting up an ICE table, one comprehends how to translate the stoichiometry of the balanced chemical equation into quantifiable changes in concentration, ultimately solving for unknowns like the hydrogen ion concentration in our exercise.

Acid dissociation is the process by which an acid releases a proton (H⁺ ion) to form its conjugate base. This process is fundamental to the behavior of acids in solution and affects pH, reactivity, and many other chemical properties. When an acid like formic acid (HCOOH) dissociates, it produces H⁺ ions and its conjugate base, in this case, the formate ion (HCOO⁻).

The strength of an acid is reflected in its tendency to dissociate, which is quantified by the acid dissociation constant (Ka). A higher Ka value indicates a stronger acid because it implies a greater degree of dissociation. Understanding acid dissociation helps predict how acids will behave in different conditions and is critical for tackling problems involving acid-base chemistry.

The concentration of hydrogen ions (H⁺) in a solution is fundamental to understanding the acidity of the solution and is measured in molarity (M). The pH of a solution is directly related to the hydrogen ion concentration, with a lower pH corresponding to a higher concentration of H⁺ ions. Determining the H⁺ concentration requires a grasp of the acid's behavior in water.

In our exercise, by using the dissociation constant and the ICE table method, we calculated this concentration for formic acid in solution. Accurately finding the hydrogen ion concentration is essential not only for pH calculations but also for analyzing buffer capabilities, electrolyte strength, and many other chemical processes that depend on the acidity of the environment.