Chemistry Exam 2 (Chapter Ch. 3 -1/2Ch.4 )
Wavelength
(λ lambda) - distance between two consecutive peaks or troughs in a wave (unit is a unit of length, typically nm)
What is the speed of light in a vacuum?
3.00 × 10⁸ m/s
Planck's constant
6.626 x 10^-34
Which color (frequency) of light travels the fastest in a vacuum?
All have same speed
What is the frequency of green light that has a wavelength of 503 nm? (c = 3.00 x 10⁸ m/s)
Answer: 5.96 × 10¹⁴ s⁻¹ 503 nm × 1 × 10^(-9)m = 5.03*10^(-7) m c=λν 3.00 x 10⁸ m/s = (5.03*10^(-7) m ) ν 5.96 × 10¹⁴ s⁻¹ = ν
Identifying Acids
Begins with a H+ ion when aqueous.
What does -ite mean?
Bonded to an oxygen. (one less than -ate). For acids it turns to (anion name)ous acid.
What does -ate mean?
Bonded with oxygen. One more than -ite. For acids it turns to (anion name)ic acid
Which element has the ground state electron configuration [Ar]4s²3d¹⁰4p⁵?
Br This electron configuration ends with 4p, meaning it is an element in the p block (a main group element on the right-hand side of the periodic table) in the fourth row. The 5 in 4p⁵ indicates that it is the fifth element in this row, so the element must be Br.
Which quantum state (n,ℓ,mℓ) is NOT possible? A) 2 0 0 B) 3 1 -1 C) 3 0 1 D) 3 2 2 E) 16 15 14
C The value for mℓ must be between -ℓ and ℓ, so if ℓ = 0, mℓ must 0 as well.
Write the chemical formula for acetic acid
C3COOH
Acetic acid
CH3COOH
Write the chemical formula for the carbonate ion.
CO3^(-2)
What is the wavelength (in nm) of a photon if the energy is 5.20 × 10⁻¹⁹ J? (h = 6.626 × 10⁻³⁴ J • s)
E=(hc)/λ 5.20 × 10⁻¹⁹ J = ((6.626 × 10⁻³⁴ J • s)(3.00 × 10⁸ m/s))/λ λ = 382 nm
What is the energy of a mole of photons that have a wavelength of 537 nm? (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)
E=(hc)/λ E= ((6.626 × 10⁻³⁴ J • s)(3.00 × 10⁸ m/s))/(5.37 * 10^(-7)) E = 2.23 × 10⁵ J
What happens to the energy of a photon if the wavelength is doubled?
Energy is reduced by one-half
Determine the correct formula for iron(III) perchlorate.
Fe(ClO4)3
Write the chemical formula for diphosphorus pentabromide
P2Br5
How are energy and wavelength related?
The energy (E) of a photon of light is proportional to its frequency (ν) or the inverse of its wavelength (λ) multiplied by Planck's constant (h): E=hν=(hc)/λ
What is Ψ?
Wave function. Describes the overall state of a quantum system.
What is the correct IUPAC name for NiS?
nickel(II) sulfide
What is the correct IUPAC name for NiHPO₄?
nickle(II) hydrogen phosphate
What is the correct IUPAC name for NI₃?
nitrogen triiodide
What is the correct IUPAC name for Sn(NO₃)₄?
tin(IV) nitrate
Broglie Wavelength Equation
λ = h/mv
What is the wavelength of light emitted when an electron transitions from n = 5 to n = 2 in a hydrogen atom?
(1/λ) = (R) (Z^(2)) [(1/n^(2)f) - (1/n^(2)i] (1/λ) = (1.097*10^(7)) (1^(2)) [(1/(2^(2))) - (1/(5^(2)))] (1/λ) = 2303700m λ = 4.3408 * 10^(-7) m * ((10^(9)nm)/1m) λ = 434 nm
Frequency
(ν nu) - number of successive wavelengths that pass a given point in a unit time (unit is hertz, Hz)
Rydberg constant
1.097 x 10^7 m^-1
What is the electron configuration of K⁺?
1s²2s²2p⁶3s²3p⁶ The element K is in the first column of the periodic table (meaning it is in the s block) and the fourth row, so its electron configuration will end with 4s¹. The electron configuration of K is 1s²2s²2p⁶3s²3p⁶4s¹. However, the K⁺ ion has one fewer electron (due to its positive charge), so the highest-energy electron must be removed from K to create K⁺, meaning its electron configuration will be 1s²2s²2p⁶3s²3p⁶.
What is the electron configuration of a neutral Fe atom?
1s²2s²2p⁶3s²3p⁶4s²3d⁶ The element Fe is a transition metal (meaning it is in the d block) and the fourth row; because elements in the d block have the quantum number n one less than their row in the periodic table, the electron configuration of Fe will end with 3d. The electron configuration of Fe is 1s²2s²2p⁶3s²3p⁶4s²3d⁶.
If n = 5, what is the maximum allowed value for ℓ? Why?
4 ℓ= 0, 1, 2, 3, 4 if n = 5 If n = 5, what is the maximum allowed value for ℓ?
In a multi-electron atom, which orbital will have the highest energy?
4f The energy of an electron is primarily dictated by its principal quantum number, n. For atoms with multiple electrons, electrons that have the same value of n (as is the case here, with n = 4) will have higher energies with higher values of ℓ. Of these options, the 4f orbital has the highest value of ℓ (ℓ = 3), so it will have the highest energy.
Write the chemical formula for carbon disulfide
CS2 carbon = C di=2 sulfide ion = S(2-) (memorized the ion) S2(2-) = 2 S atoms each with 2 negatively charged electrons = 4 negatively charged electrons C wants 4e- Chemical equation is balanced then.
Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s¹3d⁵?
Cr This electron configuration ends with 3d, meaning it is an element in the d block. Because elements in the d block have the quantum number n one less than their row in the periodic table, this element will be in the fourth row. While the 5 in 3d⁵ normally indicates that this electron configuration corresponds to the fifth entry in that row, the 4s orbital is only half-filled (with 1 electron instead of 2); if the 4s orbital were filled, it would take an electron from the 3d orbital, so 4s¹3d⁵ would change to 4s²3d⁴. This would correspond to the fourth element in that row, which is Cr. The reason the electron configuration of Cr ends in 4s¹3d⁵ instead of 4s²3d⁴ is that having two half-filled orbitals is more stable than having one partially filled (but not exactly half-filled) and one completely filled.
Which of the following elements has the smallest first ionization energy? S, O, Si, Sr, Cs
Cs Ionization energy increases from left to right and from the bottom to the top of the periodic table. Cs is the furthest to the left and closest to the bottom of the periodic table on this list. It would be predicted to have the smallest first ionization energy.
Write the chemical formula for copper(II) chlorite
Cu(ClO2)2
Identifying Ionic Compounds
First element is a metal or ammonium
Write the chemical formula for sulfuric acid
H2SO4
Write the chemical formula for chloric acid
HClO3
Write the chemical formula for hydrofluoric acid
HF
Schrödinger equation
Hψ = Eψ an equation that describes how the quantum state of a physical system changes with time H = Hamiltonian operator (something you do to the function) ψ = wavefunction (equation that describes the object completely) E = energy
Write the chemical formula for lithium hydroxide
LiOH
principle quantum #
N energy level
Write the chemical formula for dinitrogen tetroxide
N2O4
Write the chemical formula for ammonium thiocyanate
NH4SCN
Put (Mg²⁺, N³⁻, F⁻, Si⁴⁺) ionic radii in order of largest to smallest.
N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺ For isoelectronic species, anions will be larger than cations. Ions can be further ranked by considering their charges. The greater the negative charge, the larger the size. The greater the positive charge, the smaller the size
Write the chemical formula for tetraphosphorus hexasulfide
P4S6
Rank the following atoms in order of increasing first ionization energies (i.e., lowest to highest): Rb, F, Mg, B, N.
Rb < Mg < B < N < F In general, first ionization energy decreases down a group and increases across a period.
Which element has the ground state electron configuration [Kr]5s²4d¹⁰5p³?
Sb This electron configuration ends with 5p, meaning it is an element in the p block (a main group element on the right-hand side of the periodic table) in the fifth row. The 3 in 5p³ indicates that it is the third element in this row, so the element must be Sb.
quantum numbers
Set of numbers used to completely describe an electron
What does ψ² mean?
Squared wave function. Gives the probability of finding an electron in a given region of space.
Lightwave A has a greater frequency than lightwave B. Which has a greater wavelength?
Wave B
What is the electron configuration for Ba?
[Xe]6s²
What is the correct IUPAC name for Al(HSO₄)₃?
aluminum hydrogen sulfate
What is the correct IUPAC name for AlPO₄?
aluminum phosphate
What is the equation for speed of light?
c=λν
What is the wavelength of blue light that has a frequency of 6.63 × 10¹⁴ s⁻¹? (c = 3.00 × 10⁸ m/s)
c=λν 3.00 x 10⁸ m/s = λ (6.63 × 10¹⁴ s⁻¹) 4.524 x 10^(-7) m = λ
What is the correct IUPAC name for CaBr₂?
calcium bromide
What is the correct IUPAC name for CBr₄?
carbon tetrabromide carbon(C) is a non metal and bromide(Br) is a non metal so it is a molecular compond
What is the correct IUPAC name for CrCl₂?
chromium(II) chloride
What is the correct IUPAC name for CuNO₃?
copper(I) nitrate
What is the correct IUPAC name for Cl₂O₇?
dichlorine heptoxide
per-
excess or additional oxygen
Which forms of radiation has the shortest wavelength?
gamma rays
What is the correct IUPAC name for HCN(aq)?
hydrocyanic acid
How are wavelength and frequency related?
inversely proportional The bigger the wavelength, the smaller the frequency. The smaller the wavelength, the bigger the frequency.
What is the correct IUPAC name for Fe(NO₂)₂?
iron(II) nitrite
Azimuth Quantum Number
l shape
hypo-
lacking an oxygen
What is the correct IUPAC name for P₄S₃?
lead(IV) sulfite
Red light has a _____ frequency and a _____ wavelength than ultraviolet rays.
lower, longer
magnetic quantum number
m, indicates the orientation of an orbital around the nucleus
What is the correct IUPAC name for MgO?
magnesium oxide
spin quantum number
ms, has only two possible values (+1/2, -1/2) which indicate the two fundamental spin states of an electron in an orbital
How many orbitals are in the subshell when ℓ = 2?
mℓ = -2, -1, 0, 1, 2 mℓ = 5
What is the correct IUPAC name for KClO₃?
potassium chlorate
A covalent bond is formed as the result of
sharing of valence electrons
Hund's Rule
states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
What is the correct IUPAC name for SrCl₂?
strontium chloride
What is the correct IUPAC name for H₂SO₃(aq)?
sulfurous acid
What does "-ide" mean?
the element is mono atomic ion (by itself). For acids it turns to hydro(anion name)ic acid.
What is the correct IUPAC name for TiO₂?
titanium(IV) oxide
Bohr equation
ΔE = R ((1/(n^(2)f)) -(1/(n^(2)i))) n = quantum value
In the Bohr model of the hydrogen atom, the energy required to excite an electron from n = 2 to n = 3 is _______________ the energy required to excite an electron from n = 3 to n = 4?
ΔE = R ((1/(n^(2)f)) -(1/(n^(2)i))) ΔE = R ((1/3^(2))-(1/2^(2))) = -0.14R ΔE = R ((1/4^(2))-(1/3^(2))) = -0.05R |-0.14R| > |-0.05R|
What is the correct IUPAC name for HNO₂(aq)?
nitrous acid
Amplitude
one-half the distance between the peaks and troughs
What is the electron configuration of Co²⁺?
1s²2s²2p⁶3s²3p⁶3d⁷ The element Co is a transition metal (meaning it is in the d block) and the fourth row; because elements in the d block have the quantum number n one less than their row in the periodic table, the electron configuration of Co will end with 3d. The electron configuration of Co is 1s²2s²2p⁶3s²3p⁶4s²3d⁷. However, the Co²⁺ ion has two fewer electrons (due to its charge of 2+), so two electrons must be removed from the highest-energy orbital, which in this case is the 4s orbital, so Co²⁺ will have the electron configuration 1s²2s²2p⁶3s²3p⁶3d⁷.
Rank the following atoms in order of decreasing size (i.e., largest to smallest): Rb, F, Mg, B, N
Rb > Mg > B > N > F In general, atomic radius decreases across a period and increases down a group.
Which of the following electron configurations is incorrect?
S [Ne]3s³3p⁴ The s block of the periodic table represents the first two columns, indicating that s orbitals are only capable of holding 2 electrons. Therefore, the electron configuration for S cannot be [Ne]3s³3p⁴, which has 3 electrons in the 3s orbital.
Which of the following atoms would have the longest de Broglie wavelength, if all have the same velocity? A) C B) Pb C) Pd D) Ar
The de Broglie equation treats moving particles like waves, and states that the wavelength (λ) of these particles is inversely proportional to their momentum, or the product of their mass (m) and velocity (v). λ = h/(mv) For different particles moving at the same speed, the particle with the smallest mass will have the longest wavelength. Because Li is the lightest of the options given, it will have the longest de Broglie wavelength.
What atom and type (transition metal, metal, nonmetal) is the configuration 1s²2s²2p⁶3s²3p⁶4s²3d⁷ (Co)
The transition metals are in the d block of the periodic table, meaning their electron configurations will end with a partially or completely filled d orbital. Of these options, only 1s²2s²2p⁶3s²3p⁶4s²3d⁷ (Co) meets this criteria.
In the photoelectric effect, if the intensity of light shone on a metal increases, what will happen?
There will be more electrons ejected In the photoelectric effect, photons with an energy of E are shone upon a piece of metal, and if the energy of the photons overcome the work function Φ of the metal, then electrons with will be ejected from the metal with a kinetic energy KE. Each photon is capable of ejecting one electron from the metal. Therefore, increasing the intensity of the light (the number of photons shone on the metal) will increase the number of electrons ejected from the metal. Ephoton=Φ+KE
Which of the following has the electron configuration 1s²2s²2p⁶3s²3p⁶3d³?
V²⁺ The ion with the electron configuration of 1s²2s²2p⁶3s²3p⁶3d³ has a total of 21 electrons. Of the options given, the only ion with the same number of electrons is V²⁺, resulting from the electron configuration of 1s²2s²2p⁶3s²3p⁶4s²3d³ (23 total electrons) losing two electrons from the 4s orbital.
What is the electron configuration for Mn?
[Ar]4s²3d⁵ The element Mn is a transition metal (meaning it is in the d block) and the fourth row; because elements in the d block have the quantum number n one less than their row in the periodic table, the electron configuration of Mn will end with 3d. The last noble gas filled prior to Mn is Ar, so the electron configuration of Mn is [Ar]4s²3d⁵.
What is the correct IUPAC name for CoPO₄?
cobalt(III) phosphate
Molecular compounds are usually
composed of 2 or more nonmetallic elements
What is the correct IUPAC name for HNO₃(aq)?
nitric acid Know it is an acid because of the H+ion. When you take the H+ ion away the NO₃ becomes NO₃(-) ion. (Have to memorize the ion) Because you know (memorize) NO₃(-) is nitrate ion, in acids "-ate" means "-ic". So nitrate ion turns to nitric acid.
Pauli Exclusion Principle
no two electrons in a given atom can share the same set of four quantum numbers (n, ℓ, mℓ, ms).
