MCAT Exam Study Guide | 700+ High-Yield Flashcards
What is the aufbau principle? Electrons fill orbitals starting from the lowest energy level to the highest energy level
What is Hund's rule? Electrons fill degenerate orbitals singly before pairing up, and all unpaired electrons
have parallel spins
What is the Pauli exclusion principle? No two electrons in an atom can have the same four quantum numbers
What are the four quantum numbers? Principal (n), angular momentum (l), magnetic (ml), and spin (ms)
What does the principal quantum number (n) represent? Energy level and size of the orbital; n = 1, 2, 3, etc.
What does the angular momentum quantum number (l) Shape of the orbital; l = 0 to (n-1); s=0, p=1, d=2, f=3
represent?
What is electronegativity? The ability of an atom to attract electrons in a chemical bond
Which element has the highest electronegativity? Fluorine (F)
How does electronegativity trend across a period? Increases from left to right
How does electronegativity trend down a group? Decreases down a group
What is ionization energy? The energy required to remove an electron from a gaseous atom
How does ionization energy trend across a period? Increases from left to right
How does ionization energy trend down a group? Decreases down a group
What is electron affinity? The energy change when an electron is added to a gaseous atom
What is atomic radius? The distance from the nucleus to the outermost electron shell
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
How does atomic radius trend across a period? Decreases from left to right
How does atomic radius trend down a group? Increases down a group
What is the formula for molarity (M)? M = moles of solute / liters of solution
What is the formula for molality (m)? m = moles of solute / kilograms of solvent
What is the formula for mole fraction? Mole fraction = moles of component / total moles
What is Avogadro's number? 6.022 × 10²³ particles per mole
What is the ideal gas law? PV = nRT
What is the value of R in the ideal gas law? 0.0821 L·atm/(mol·K) or 8.314 J/(mol·K)
What is Dalton's law of partial pressures? The total pressure of a gas mixture equals the sum of the partial pressures of each
gas
What is Graham's law of effusion? Rate of effusion is inversely proportional to the square root of molar mass
What is a Lewis acid? An electron pair acceptor
What is a Lewis base? An electron pair donor
What is a Brønsted-Lowry acid? A proton (H⁺) donor
What is a Brønsted-Lowry base? A proton (H⁺) acceptor
What is the pH formula? pH = -log[H⁺]
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
What is the pOH formula? pOH = -log[OH⁻]
What is the relationship between pH and pOH? pH + pOH = 14 (at 25°C)
What is the Henderson-Hasselbalch equation? pH = pKa + log([A⁻]/[HA])
What is a buffer? A solution that resists pH changes when small amounts of acid or base are added
What makes an effective buffer? When pH is within ±1 of the pKa and equal concentrations of weak acid and
conjugate base
What is Kw for water at 25°C? 1.0 × 10⁻¹⁴
What is Ka? The acid dissociation constant
What is Kb? The base dissociation constant
What is the relationship between Ka and Kb? Ka × Kb = Kw
What is a strong acid? An acid that completely dissociates in water
Name six strong acids HCl, HBr, HI, HNO₃, H₂SO₄, HClO₄
What is a weak acid? An acid that partially dissociates in water
What is a strong base? A base that completely dissociates in water
Name the strong bases Group 1 hydroxides (LiOH, NaOH, KOH, etc.) and heavy Group 2 hydroxides
(Ca(OH)₂, Sr(OH)₂, Ba(OH)₂)
What is an ionic bond? Electrostatic attraction between oppositely charged ions
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
What is a covalent bond? Sharing of electron pairs between atoms
What is a polar covalent bond? Unequal sharing of electrons due to electronegativity difference (0.5-1.7)
What is a nonpolar covalent bond? Equal or nearly equal sharing of electrons (electronegativity difference < 0.5)
What are London dispersion forces? Weak intermolecular forces caused by temporary dipoles in nonpolar molecules
What are dipole-dipole forces? Intermolecular forces between polar molecules
What is hydrogen bonding? Strong dipole-dipole interaction when H is bonded to N, O, or F
What is the strongest intermolecular force? Hydrogen bonding
What is sublimation? Direct transition from solid to gas without passing through liquid phase
What is deposition? Direct transition from gas to solid without passing through liquid phase
What is the triple point? Temperature and pressure where all three phases coexist in equilibrium
What is the critical point? Temperature and pressure above which liquid and gas phases are indistinguishable
What is colligative property? Property that depends only on the number of solute particles, not their identity
Name four colligative properties Vapor pressure lowering, boiling point elevation, freezing point depression, osmotic
pressure
What is Raoult's law? Vapor pressure of solution = (mole fraction of solvent) × (vapor pressure of pure
solvent)
What is boiling point elevation formula? ΔTb = Kb × m × i
Grade A+ | Updated
What is the aufbau principle? Electrons fill orbitals starting from the lowest energy level to the highest energy level
What is Hund's rule? Electrons fill degenerate orbitals singly before pairing up, and all unpaired electrons
have parallel spins
What is the Pauli exclusion principle? No two electrons in an atom can have the same four quantum numbers
What are the four quantum numbers? Principal (n), angular momentum (l), magnetic (ml), and spin (ms)
What does the principal quantum number (n) represent? Energy level and size of the orbital; n = 1, 2, 3, etc.
What does the angular momentum quantum number (l) Shape of the orbital; l = 0 to (n-1); s=0, p=1, d=2, f=3
represent?
What is electronegativity? The ability of an atom to attract electrons in a chemical bond
Which element has the highest electronegativity? Fluorine (F)
How does electronegativity trend across a period? Increases from left to right
How does electronegativity trend down a group? Decreases down a group
What is ionization energy? The energy required to remove an electron from a gaseous atom
How does ionization energy trend across a period? Increases from left to right
How does ionization energy trend down a group? Decreases down a group
What is electron affinity? The energy change when an electron is added to a gaseous atom
What is atomic radius? The distance from the nucleus to the outermost electron shell
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
How does atomic radius trend across a period? Decreases from left to right
How does atomic radius trend down a group? Increases down a group
What is the formula for molarity (M)? M = moles of solute / liters of solution
What is the formula for molality (m)? m = moles of solute / kilograms of solvent
What is the formula for mole fraction? Mole fraction = moles of component / total moles
What is Avogadro's number? 6.022 × 10²³ particles per mole
What is the ideal gas law? PV = nRT
What is the value of R in the ideal gas law? 0.0821 L·atm/(mol·K) or 8.314 J/(mol·K)
What is Dalton's law of partial pressures? The total pressure of a gas mixture equals the sum of the partial pressures of each
gas
What is Graham's law of effusion? Rate of effusion is inversely proportional to the square root of molar mass
What is a Lewis acid? An electron pair acceptor
What is a Lewis base? An electron pair donor
What is a Brønsted-Lowry acid? A proton (H⁺) donor
What is a Brønsted-Lowry base? A proton (H⁺) acceptor
What is the pH formula? pH = -log[H⁺]
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
What is the pOH formula? pOH = -log[OH⁻]
What is the relationship between pH and pOH? pH + pOH = 14 (at 25°C)
What is the Henderson-Hasselbalch equation? pH = pKa + log([A⁻]/[HA])
What is a buffer? A solution that resists pH changes when small amounts of acid or base are added
What makes an effective buffer? When pH is within ±1 of the pKa and equal concentrations of weak acid and
conjugate base
What is Kw for water at 25°C? 1.0 × 10⁻¹⁴
What is Ka? The acid dissociation constant
What is Kb? The base dissociation constant
What is the relationship between Ka and Kb? Ka × Kb = Kw
What is a strong acid? An acid that completely dissociates in water
Name six strong acids HCl, HBr, HI, HNO₃, H₂SO₄, HClO₄
What is a weak acid? An acid that partially dissociates in water
What is a strong base? A base that completely dissociates in water
Name the strong bases Group 1 hydroxides (LiOH, NaOH, KOH, etc.) and heavy Group 2 hydroxides
(Ca(OH)₂, Sr(OH)₂, Ba(OH)₂)
What is an ionic bond? Electrostatic attraction between oppositely charged ions
Grade A+ | Updated
, MCAT Exam Study Guide | 700+ High-Yield Flashcards
What is a covalent bond? Sharing of electron pairs between atoms
What is a polar covalent bond? Unequal sharing of electrons due to electronegativity difference (0.5-1.7)
What is a nonpolar covalent bond? Equal or nearly equal sharing of electrons (electronegativity difference < 0.5)
What are London dispersion forces? Weak intermolecular forces caused by temporary dipoles in nonpolar molecules
What are dipole-dipole forces? Intermolecular forces between polar molecules
What is hydrogen bonding? Strong dipole-dipole interaction when H is bonded to N, O, or F
What is the strongest intermolecular force? Hydrogen bonding
What is sublimation? Direct transition from solid to gas without passing through liquid phase
What is deposition? Direct transition from gas to solid without passing through liquid phase
What is the triple point? Temperature and pressure where all three phases coexist in equilibrium
What is the critical point? Temperature and pressure above which liquid and gas phases are indistinguishable
What is colligative property? Property that depends only on the number of solute particles, not their identity
Name four colligative properties Vapor pressure lowering, boiling point elevation, freezing point depression, osmotic
pressure
What is Raoult's law? Vapor pressure of solution = (mole fraction of solvent) × (vapor pressure of pure
solvent)
What is boiling point elevation formula? ΔTb = Kb × m × i
Grade A+ | Updated
