What is chemical equilibrium?	The state where the forward and reverse reaction rates are equal, so the concentrations of reactants and products remain constant over time.
What does the equilibrium constant (Keq) expression represent?	The ratio of product concentrations to reactant concentrations, each raised to the power of their stoichiometric coefficients, at equilibrium.
What does a large Keq value indicate?	The equilibrium lies far to the right, meaning products are heavily favored at equilibrium.
State Le Chatelier's principle.	When a system at equilibrium is disturbed, it shifts in the direction that partially counteracts the change and restores a new equilibrium.
How does adding more reactant affect equilibrium?	The system shifts toward products (right) to consume the added reactant and re-establish equilibrium.
How does a catalyst affect equilibrium?	A catalyst speeds up both the forward and reverse reactions equally. It does not change the equilibrium position or the value of Keq.
What is the relationship between Kp and Kc?	Kp = Kc(RT)^delta_n, where delta_n is the change in moles of gas (moles gaseous products minus moles gaseous reactants).
What is the reaction quotient (Q) used for?	Q is calculated the same way as Keq but at non-equilibrium conditions. If Q < K, the reaction shifts right; if Q > K, it shifts left.
What defines a Bronsted-Lowry acid?	A proton (H+) donor. Its conjugate base is the species formed after it donates a proton.
What is the pH of a solution?	pH = -log[H+]. A pH below 7 is acidic, 7 is neutral, and above 7 is basic at 25 degrees C.
What is the relationship between Ka and Kb for a conjugate acid-base pair?	Ka x Kb = Kw = 1.0 x 10^-14 at 25 degrees C. A stronger acid has a weaker conjugate base.
How do you calculate the pH of a strong acid solution?	Strong acids dissociate completely, so [H+] equals the initial acid concentration. pH = -log[H+] directly.
What is a buffer solution?	A solution containing a weak acid and its conjugate base (or weak base and its conjugate acid) that resists changes in pH upon addition of small amounts of acid or base.
What is the Henderson-Hasselbalch equation?	pH = pKa + log([A-]/[HA]). It is used to calculate the pH of buffer solutions.
What happens at the equivalence point of a strong acid-strong base titration?	All the acid has been neutralized by the base. The solution is neutral (pH = 7) because the conjugate species do not hydrolyze.
Why is the equivalence point pH above 7 in a weak acid-strong base titration?	At the equivalence point, only the conjugate base of the weak acid remains in solution. It hydrolyzes water, producing OH- and raising the pH above 7.
What is the half-equivalence point in a weak acid titration?	The point where half the acid has been neutralized, so [HA] = [A-] and pH = pKa. This is used to determine the Ka of the weak acid.