Test 4 Flashcards
Acid-base buffer
A solution that resists changes in the pH when a small amount of either strong acid or strong base is added
common-ion effect
The sift in the position of an ionic equilibrium away from an ion involved in the process that is caused by the addition or presence of that ion
Henderson-Hasselbalch equation
An equation for calculating the pH of a buffer system.
buffer capacity
A measure of the ability of a buffer to resist a change in pH; related to the total concentrations and relative proportions of buffer components
buffer range
The pH range over which a buffer acts effectively
acid-base titration curve
A plot of the pH of a solution of acid versus the volume of base added to the solution
equivalence point
The point in a titration when the number of moles of the added species is stoichiometrically equivalent to the original number of moles of the other species
end point
The point in a titration at which the indicator changes color.
solubility-product
An equilibrium constant for a slightly soluble ionic compound dissolving in water.
complex ion
An ion consisting of a central metal ion bonded covalently to molecules and/or anions called ligands
ligand
A molecule or anion bonded to a central metal ion in a complex ion.
formation constant(Kf)
An equilibrium constant for the formation of a complex ion from the hydrated metal ion and ligands.
spontaneous change
A change that occurs by itself, that is , without an on going input of external energy.
entropy
A thermodynamic quantity related tot he number of ways the energy of a system can be dispersed through the motions of its particles
second law of thermodynamics
A law stating that a process occurs spontaneously in the direction that increases the entropy of the universe
third law of thermodynamics
A law stating that the entropy of a perfect crystal is zero at 0 K
standard molar entropy
The entropy of 1 mol of an ideal gas at standard temperature and pressure
standard entropy of reaction
The entropy change that occurs when all components are in their standard states
free energy
A thermodynamic quantity that is the difference between the enthalpy and the product of the absolute temperature and the entropy: G= H-TS
standard free energy of formation
The standard free energy change that occurs when 1 mol of a compound is made from its elements with all components in their standard states.
coupling of reactions
The pairing of reactions of which one releases enough free energy for the other to occur
adenosine triphosphate
A high energy molecule that serves most commonly as a store and source of energy in organisms
electrochemistry
The study of the relationship between chemical change and electrical work
electrochemical cell
A system that incorporates a redox reaction to produce or use electrical energy
