Review Sheet for Midterm #2

Empirical information and Formulas you are expected to memorize

• E = hn = hc/l
• nl = c (for electromagnetic radiation (light))
• 1 nm = 1 ´ 10^-9 m
• 1 Å = 1 ´ 10^-10 m
• E_n = (-R_H/n²) (for the energy levels in a hydrogen atom)
• l = h/(mv) (the wave behavior of matter)

Empirical Information you are not expected to memorize

• The values of constants such as h, c, and R_H
• Specific values of ionization energy, atomic and ionic radii, and electron affinities

Chapter 5

• Be able to calculate the work done by moving an object against an opposing force (i.e. by lifting an object)
• Be able to use the first law of thermodynamics to determine either DE, w or q
• Understand the sign convention for heat and work
• Distinguish endothermic and exothermic processes and reactions
• Understand the difference between state functions and non-state functions
• Be able to calculate the enthalpy change for a reaction
• Given DH_rxn and the mass of a reactant calculate the total heat evolved/absorbed
• Calorimetry (constant pressure only) problems
• Use Hess’s Law to calculate the enthalpy change for a reaction
• Use enthalpies of formation to calculate enthalpies of reaction

Chapter 6

• Be able to convert between wavelength, frequency and energy of a photon
• Given the wavelength or frequency and the total energy of a pulse of light, calculate the number of photons in the pulse.
• Understand the principles behind the photoelectric effect
• Be able to calculate the energy of the photon emitted/absorbed when an electron changes levels in the hydrogen atom (Bohr model of the hydrogen atom)
• Be able to convert between wavelength and velocity of matter (DeBroglie relation)
• Understand the implications of the uncertainty principle
• Understand the four quantum numbers used to specify the state of an electron in an atom. Know their possible values, understand how to describe the shape and energy of the orbital from these quantum numbers.
• Know the correspondence between the numerical values of the azimuthal quantum number and the letters used to describe the orbitals (i.e. l = 1 is a p orbital).
• Understand how effective nuclear charge in a multielectron atom, removes the degeneracy of orbitals with the same value of n, but different values of l
• Use Hund’s rule and the Pauli exclusion principle to derive the electron configuration of any atom
• Understand how the electron configuration of the atoms relates to the periodic table
• Derive orbital diagrams and use them to determine the quantum numbers of an electron or a group of electrons, or determine the number of unpaired electrons

Chapter 7

• Be able to determine the # of valence electrons for any atom from the periodic table
• Understand the definitions of the atomic properties: atomic radius, ionization energy, electron affinity and electronegativity
• Know the periodic trends in atomic radius, ionization energy, electron affinity and electronegativity
• Be able to qualitatively compare the radius and ionization energy of atoms in an isoelectronic series (O^2-, F^-, Ne, Na⁺, Mg²⁺)
• Understand the difference between 1^st, 2^nd, etc. ionization energy and know qualitatively how the ionization energies change as the ionic charge increases
• Be able to distinguish acidic oxides from basic oxides