CHEM 115 STUDY GUIDE EXAM 2026/2027 QUESTIONS
AND SOLUTIONS RATED A+
✔✔Energy equation - ✔✔E=hv or E=hc/wavelength
✔✔1 Hz = - ✔✔1 wave per second
✔✔c= - ✔✔3.00 x 10^8 m/s
✔✔c= equation - ✔✔v*lamda (frequency * wavelength)
✔✔R= - ✔✔0.0821 L atm/mol K
✔✔(b) R= - ✔✔8.314 J/Kmol
✔✔1 J = - ✔✔1 kg m^2/s^2
✔✔1 amu= - ✔✔931.5 MeV
✔✔(b) 1 amu= - ✔✔1.66054 x 10^-27 kg
✔✔PV= - ✔✔nRT
✔✔ln(Nt/No)= - ✔✔-kt
✔✔Integrated Rate ln(No/Nt)= - ✔✔kt
✔✔t(1/2)= - ✔✔ln2/k=0.693/k
✔✔Nt/No= - ✔✔(1/2)^n (where n is number of half lives)
✔✔Rydberg Equation - ✔✔1/wavelength = R (1/n1^2 - 1/n2^2) for H atom, where n2>n1
✔✔R (Rydberg constant) - ✔✔(1.096776 x 10^7) /m
✔✔Bohr's Equation - ✔✔change in energy= -2.18x10^-18J(1/n2 final-1/n2 initial)
for H atom
✔✔En= - ✔✔-2.18 x10^-18 J (z^2/n^2)
✔✔Below band of stability - ✔✔Electron capture or positron emission, (proton becomes
a neutron) z reduced by 1
, ✔✔Above band of stability - ✔✔alpha decay,A reduces by 4 and Z reduces by 2
✔✔electron capture - ✔✔Z reduced by 1 and A unchanged
✔✔positron emission - ✔✔Z reduced by 1 A unchanged
✔✔Beta decay - ✔✔Z increases by 1 A unchanged
✔✔Gamma Emission decay - ✔✔no change in Z or A and accompanies Beta Decay
from excited nucleus , high energy
✔✔alpha decay - ✔✔Z decreases by 2 and A decreases by 4
✔✔conversion factor Angstrom to nm - ✔✔1 Angstrom = 0.1 nm
✔✔conversion factor MeV to J - ✔✔1 MeV = 1.602E-18 J
✔✔Quantum numbers: n - ✔✔principal quantum number, positive integer, the numbers
preceding electron configurations 1s^2, n=1, n determines the energy of the orbital thee
higher n is the higher the energy value
✔✔Quantum numbers: l - ✔✔angular momentum quantum number, integer 0 - (n-1),
value of l indicates shape of orbital
✔✔Quantum numbers: m1 - ✔✔magnetic quantum number, integer from -l to +l, the
value of m indicates spatial orientation of the orbital
✔✔Orbitals: s - ✔✔holds 2 electrons, sperical
✔✔Orbitals: p - ✔✔holds 6 electrons, l=1
✔✔Orbitals: d - ✔✔holds 10 electrons, l=2
✔✔percent error formula - ✔✔|accepted value-measured value| / accepted value x100
✔✔change in energy = - ✔✔change in nuclear binding energy
✔✔nuclear binding energy= - ✔✔1.68 E^-11 J / nuclide
✔✔1MeV/nuclide= - ✔✔1.6E^-13 J/nuclide
✔✔BE/nuclide - ✔✔NBE/mass number
AND SOLUTIONS RATED A+
✔✔Energy equation - ✔✔E=hv or E=hc/wavelength
✔✔1 Hz = - ✔✔1 wave per second
✔✔c= - ✔✔3.00 x 10^8 m/s
✔✔c= equation - ✔✔v*lamda (frequency * wavelength)
✔✔R= - ✔✔0.0821 L atm/mol K
✔✔(b) R= - ✔✔8.314 J/Kmol
✔✔1 J = - ✔✔1 kg m^2/s^2
✔✔1 amu= - ✔✔931.5 MeV
✔✔(b) 1 amu= - ✔✔1.66054 x 10^-27 kg
✔✔PV= - ✔✔nRT
✔✔ln(Nt/No)= - ✔✔-kt
✔✔Integrated Rate ln(No/Nt)= - ✔✔kt
✔✔t(1/2)= - ✔✔ln2/k=0.693/k
✔✔Nt/No= - ✔✔(1/2)^n (where n is number of half lives)
✔✔Rydberg Equation - ✔✔1/wavelength = R (1/n1^2 - 1/n2^2) for H atom, where n2>n1
✔✔R (Rydberg constant) - ✔✔(1.096776 x 10^7) /m
✔✔Bohr's Equation - ✔✔change in energy= -2.18x10^-18J(1/n2 final-1/n2 initial)
for H atom
✔✔En= - ✔✔-2.18 x10^-18 J (z^2/n^2)
✔✔Below band of stability - ✔✔Electron capture or positron emission, (proton becomes
a neutron) z reduced by 1
, ✔✔Above band of stability - ✔✔alpha decay,A reduces by 4 and Z reduces by 2
✔✔electron capture - ✔✔Z reduced by 1 and A unchanged
✔✔positron emission - ✔✔Z reduced by 1 A unchanged
✔✔Beta decay - ✔✔Z increases by 1 A unchanged
✔✔Gamma Emission decay - ✔✔no change in Z or A and accompanies Beta Decay
from excited nucleus , high energy
✔✔alpha decay - ✔✔Z decreases by 2 and A decreases by 4
✔✔conversion factor Angstrom to nm - ✔✔1 Angstrom = 0.1 nm
✔✔conversion factor MeV to J - ✔✔1 MeV = 1.602E-18 J
✔✔Quantum numbers: n - ✔✔principal quantum number, positive integer, the numbers
preceding electron configurations 1s^2, n=1, n determines the energy of the orbital thee
higher n is the higher the energy value
✔✔Quantum numbers: l - ✔✔angular momentum quantum number, integer 0 - (n-1),
value of l indicates shape of orbital
✔✔Quantum numbers: m1 - ✔✔magnetic quantum number, integer from -l to +l, the
value of m indicates spatial orientation of the orbital
✔✔Orbitals: s - ✔✔holds 2 electrons, sperical
✔✔Orbitals: p - ✔✔holds 6 electrons, l=1
✔✔Orbitals: d - ✔✔holds 10 electrons, l=2
✔✔percent error formula - ✔✔|accepted value-measured value| / accepted value x100
✔✔change in energy = - ✔✔change in nuclear binding energy
✔✔nuclear binding energy= - ✔✔1.68 E^-11 J / nuclide
✔✔1MeV/nuclide= - ✔✔1.6E^-13 J/nuclide
✔✔BE/nuclide - ✔✔NBE/mass number
