acid base equilibria Flashcards
What is the definition of Brønsted-Lowry acids?
Brønsted-Lowry acids are proton donors; they release hydrogen ions (H⁺) when mixed with water. These H⁺ ions are always combined with H₂O to form hydronium ions (H₃O⁺) in aqueous solutions.
What is the definition of Brønsted-Lowry bases?
Brønsted-Lowry bases are proton acceptors; they grab hydrogen ions from water molecules when in solution.
Describe the dissociation of strong acids and strong bases in water.
Strong acids, such as hydrochloric acid, dissociate almost completely in water, releasing nearly all of their H⁺ ions.
Strong bases, like sodium hydroxide, also dissociate almost completely in water, producing high concentrations of hydroxide ions (OH⁻).
Describe the dissociation of weak acids and weak bases in water.
Weak acids, like ethanoic acid, dissociate only slightly in water, producing small numbers of H⁺ ions. The equilibrium lies well to the left.
Weak bases, such as ammonia, only slightly protonate in water, and the equilibrium also lies well to the left.
What condition must be met for an acid to donate its proton in an acid-base reaction?
An acid can only donate its proton if there is a base to accept it. In an acid-base reaction, the acid (HA) transfers a proton to the base (B).
How does Le Chatelier’s principle explain the effect of adding reactants or products on the equilibrium position in an acid-base reaction?
Adding more HA or B shifts the equilibrium to the right, favoring the formation of more products.
Adding more BH⁺ or A⁻ shifts the equilibrium to the left, favoring the formation of more reactants.
These shifts in equilibrium are explained by Le Chatelier’s principle, which predicts that a system at equilibrium will respond to changes by counteracting them to restore equilibrium.
What are conjugate pairs in the context of acid-base reactions?
Conjugate pairs are species linked by the transfer of a proton in an acid-base reaction. They are always found on opposite sides of the reaction equation.
What defines the conjugate acid and conjugate base in an acid-base reaction?
The species that has lost a proton becomes the conjugate base, while the species that has gained a proton becomes the conjugate acid.
What are the products of a reaction between an acid and a base?
When acids and bases react together, they produce a salt and water.
What defines a neutral solution in terms of the concentrations of H⁺ and OH⁻ ions?
A neutral solution is produced when the concentration of H⁺ ions from the acid is equal to the concentration of OH⁻ ions from the base, resulting in [H⁺] = [OH⁻]. All H⁺ ions from the acid and OH⁻ ions from the base react to form water.
What is the name of the enthalpy change associated with neutralization reactions?
The enthalpy change associated with neutralization reactions is called the enthalpy change of neutralization.
what is the standard enthalpy change of neutralisation defined as
The standard enthalpy change of neutralisation is the enthalpy change when solutions of an acid and a base react together, under standard conditions, to produce 1 mole of water.
How do chemists express the concentration of hydrogen ions?
Chemists use a logarithmic scale known as pH to express the concentration of hydrogen ions.
why do chemist use the logarithmic scale to express the concentration of hydrogen ions
because the numbers vary enormously
What is the range of the pH scale, and what value is considered neutral?
The pH scale typically ranges from 0 (very acidic) to 14 (very alkaline/basic), with pH 7 considered neutral.
