Chemistry - equations Flashcards
Density
mass/volume
Force
Mass × acceleration
Energy
F × d or (m × a × d)
Potential Energy
m × g × h
Kinetic Energy
0.5 × m × v^2
Electromagnetic Energy
k × ( (q1 × q2)/r ) where k = constant q = charge r = distance of two charges
Total Intensity
(5.67E-8 W × mE-2 × kE-4) × TE4 where t = temperature
Avogadros Number (how used)
Moles <-> number of particles (atoms/molecules)
Percent Composition
(mass of an element in a sample/total mass of the sample) × 100
Speed of light (c)
2.9979E8 m/s
c=
λ × v
The frequency of light with a wavelength of 258 nm is?
1.16E15 1/s
E =
hv where h = planks constant v = frequency
Calculate the energy of the red light photon with a wavelength of 7000 angstroms (1 angstrom = 1E-10 m)
3E-19 J
ΔE =
-2.178E-18 J ( (1/n^2 final) - (1/n^2 initial) )
1/λ =
Rydberg constant ( (1/n^2 final) - (1/n^2 initial) )
Calculate the wavelength of light emitted when an electron of hydrogen moves from n=5 to n=3
1.281E-6 m
Heisenberg Uncertainty Principle
∆x × ∆(mv) ≥ (h/4π) where x = position of the particle ∆x = uncertainty in the particle’s position ∆(mv) = uncertainty in the particles position
If the maximum velocity of an electron in copper wire is about 1.7E8 cm/s with an uncertainty ≤ 1.0% (of velocity), how accurately can the electron’s position be determined? In other words, what is the uncertainty in the position of the electron (in meters)? Where mass of an electron = 9.10938188E-31 kg
∆x ≥ 3.4E-9 m
Ephoton =
hv = (hc)/λ
The speed of an electron emitted from the surface of a sample of potassium by a photon is 668 km/s. What is the kinetic energy of the ejected electron? Where mass of an electron = 9.10938188E-31 kg
2.03E-19 J
The work function (threshold) of the potassium is 2.29 eV. What is the wavelength of the radiation that caused photo-ejection of the electron? Where 1 eV = 1.602E-19 J
3.48E-7 m
The speed of an electron emitted from the surface of a sample of potassium by a photon is 668 km/s. What is the longest wavelength of electromagnetic radiation that could eject electrons from potassium?
5.41E-7 m
De Broglie Equation λ =
h/(m × v) where v = velocity
Calculate the wavelength of a baseball with a mass of 150 g moving with a speed of 70 mi/hr.
1E-34 m
Calculate the wavelength of a electron with a mass of 9.1E-31 kg moving about the hydrogen atom with a speed of 2,200 km/s
3.3E-10 m
3p5
n = 3, ℓ = 1, mℓ = 0, ms = -1/2
5f13
n = 5, ℓ = 3, mℓ = 2, ms = -1/2
Electron configuration of P
1s^2 2s^2 2p^6 3s^2 3p^3
For principal quantum level n=3, determine the number of allowed subshells (different values of ℓ), and give the designation of each.
of allowed subshells = 3
ℓ = 0 (3s)
ℓ = 1 (3p)
ℓ = 2 (3d)
For ℓ = 2, determine the magnetic quantum numbers (mℓ) and the number of orbitals
magnetic quantum numbers = -2, -1, 0, 1, 2
number of orbitals = 5
Photoelectric Effect
Ekinetic = hv - hv0
The minimum energy required to eject an electron
Hv0
