ACS Chemistry Final Exam 182 Questions with Verified Answers
Layout of an element (mass # & atomic #) - CORRECT ANSWER
atomic number = - CORRECT
... [Show More] ANSWER # of protons
mass number = - CORRECT ANSWER # of protons + neutrons
the number of protons in a neutral atom will equal the - CORRECT ANSWER # of electrons
how to find the correct number of neutrons - CORRECT ANSWER mass number - atomic number
Forms of the same elements that differ in amount of neutrons - CORRECT ANSWER isotopes
What particle, if lost from the nucleus, would NOT cause a change in the atomic number? - CORRECT ANSWER a neutron because it has no charge
When alpha particles were shot at a metal foil target, most passed through without deflections, while others deflected at large angles. What did this suggest to Rutherford? - CORRECT ANSWER that the atoms of the metal were mostly empty space, while the nucleus consisted of most of the mass which included highly condensed positive particles (which caused the deflection).
An atom has a valence shell configuration of 1s1. To which group of elements on the periodic table does it belong? - CORRECT ANSWER IA
alkali metals
electromagnetic spectrum - CORRECT ANSWER
The greater the wavelength of a photon..? - CORRECT ANSWER the lower its frequency
The greater the frequency of a photon...? - CORRECT ANSWER the shorter its wavelength
Light energy formula - CORRECT ANSWER
What does C in the light energy formula represent? - CORRECT ANSWER
Give the ground-state electron configuration of an atom in the second period - CORRECT ANSWER 1s2 2s1
Electrons configuration rule that states electrons do not pair until they have to. (put one electrons in each electron domain then pair up) - CORRECT ANSWER Hund's rule
An experimental phenomena associated with atoms having unpaired electrons - which states such substances are attracted to magnetic fields - CORRECT ANSWER Paramagnetism
Which drop in energy level results in the greatest emission of energy? - CORRECT ANSWER n=2 to n=1
quantum numbers - CORRECT ANSWER
What do the 4 quantum numbers stand for? - CORRECT ANSWER n = energy level
l = (n-1)
ml -l to l
mn 1/2 or -1/2 (spin)
List the quantum numbers for the s, p, d, and f orbitals - CORRECT ANSWER s 1,0,0
p 2, 1, -1-0-1
d 3, 2, -2--1-0-1-2
f 4, 3 -3--2--1-0-1-2-3
Py orbital - CORRECT ANSWER
Which element is represented by X - CORRECT ANSWER Chromium
What two subatomic particles have the most mass, but occupy very little of the volume of an atom - CORRECT ANSWER protons and neutrons
Define Isoelectronic - CORRECT ANSWER Having the same amount of electrons
How does a sodium ion differ from a sodium atom? - CORRECT ANSWER the sodium ion has fewer electrons
two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties - CORRECT ANSWER isomer
two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are all ________ of carbon. - CORRECT ANSWER allotropes
What makes up an alpha particle? - CORRECT ANSWER 2 protons and 2 neutrons
What did Millikan discover from his oil drop experiments? - CORRECT ANSWER the magnitude of the charge on an electron
Periods vs Groups - CORRECT ANSWER
when an atom of an electropositive atom becomes an ion it..? - CORRECT ANSWER becomes larger
Nearly all the mass in an atom is located _________ because both ______ & ______ are located there, and each of these particles have a mass larger than the ______ - CORRECT ANSWER inside the nucleus
protons & neutrons
electron
Classify the following as an element, compound, or mixture. If it is a mixture, decide if it is a homogeneous or heterogeneous mixture.
1 Sugar
2 Spaghetti Sauce
3 Phosphorus - CORRECT ANSWER 1 compound, not a mixture
2 mixture, heterogenous
3 element
Properties that do depend on the amount of matter present. - CORRECT ANSWER extensive
Dz^2 orbital - CORRECT ANSWER
Dxy orbital - CORRECT ANSWER
Dx^2y^2 orbital - CORRECT ANSWER
List the shape, electron domain geometry, and predicted bond angle of a molecule with 6 electron domains - CORRECT ANSWER Octahedral
90º
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (4 bonding 0 nonbonding) - CORRECT ANSWER electron domain geometry: tetrahedral
molecular geometry: tetrahedral
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (3 bonding 1 nonbonding) - CORRECT ANSWER electron domain geometry: tetrahedral
molecular geometry: trigonal pyramidal
ex: NH3
List the electron domain geometry & molecular geometry of a molecule with 3 electron domains (2 bonding 1nonbonding) - CORRECT ANSWER electron domain geometry: trigonal planar
molecular geometry: bent
List the electron domain geometry & molecular geometry of a molecule with 3 electron domains (3 bonding 0 nonbonding) - CORRECT ANSWER electron domain geometry: trigonal planar
molecular geometry: trigonal planar
List the electron domain geometry & molecular geometry of a molecule with 2 electron domains (2 bonding 0 nonbonding) - CORRECT ANSWER electron domain geometry: linear
molecular geometry: linear
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (2 bonding 2 nonbonding) - CORRECT ANSWER electron domain geometry: tetrahedral
molecular geometry: bent/nonlinear
ex: H2O
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (5 bonding 0 nonbonding) - CORRECT ANSWER electron domain geometry: trigonal bipyramidal
molecular geometry: trigonal bipyramidal
ex: PCl5
List the electron domain geometry & molecular geometry of a molecule with 6 electron domains (6 bonding 0 nonbonding) - CORRECT ANSWER electron domain geometry: octahedral
molecular geometry: octahedral
ex: SF6
List the electron domain geometry & molecular geometry of a molecule with 6 electron domains (5 bonding 1 nonbonding) - CORRECT ANSWER electron domain geometry: octahedral
molecular geometry: square pyramidal
ex: BrF5
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (2 bonding 3 nonbonding) - CORRECT ANSWER electron domain geometry: trigonal bipyramidal
molecular geometry: linear
ex: I3-
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (3 bonding 2 nonbonding) - CORRECT ANSWER electron domain geometry: trigonal bipyramidal
molecular geometry: t-shaped
ex: CIF3
List the electron domain geometry & molecular geometry of a molecule with 5 electron domains (4 bonding 1 nonbonding) - CORRECT ANSWER electron domain geometry: trigonal bipyramidal
molecular geometry: see saw shape
ex: SF4
List the shape, electron domain geometry, and predicted bond angle of a molecule with 5 electron domains - CORRECT ANSWER trigonal bipyramidal, 120º equitorial & 90º axial
List the shape, electron domain geometry, and predicted bond angle of a molecule with 4 electron domains - CORRECT ANSWER tetrahedral 109.5º
List the shape, electron domain geometry, and predicted bond angle of a molecule with 2 electron domains - CORRECT ANSWER linear 180º
List the shape, electron domain geometry, and predicted bond angle of a molecule with 3 electron domains - CORRECT ANSWER trigonal planar 120º
What does a nonbonding electron domain represent? - CORRECT ANSWER a lone PAIR of electrons
What does a bonding electron domain represent? - CORRECT ANSWER a bond. single or multiple
how many valence electrons does hydrogen have? - CORRECT ANSWER 2
Identify the bond that would form between an element with a low ionization energy and an element with a high electron affinity - CORRECT ANSWER an ionic bond
What does it mean when an element has a low ionization energy? - CORRECT ANSWER It means that it can easily lose electrons
What does it mean when an element has a high electron affinity - CORRECT ANSWER It means that it can easily accept electrons to form negative ions
The type of bond that results when both elements contribute electrons to form a shared pair - CORRECT ANSWER covalent bonds
The type of bond that results when both elements contribute electrons but one element furnishes both electrons - CORRECT ANSWER coordinate covalent bond
High energy photons have enough energy to do what? - CORRECT ANSWER disrupt covalent bonds
What has to be true of a non polar molecule that has polar bonds - CORRECT ANSWER it must be symmetric enough so that all the dipoles cancel out
a molecule in which a concentration of positive electric charge is separated from a concentration of negative charge. - CORRECT ANSWER dipole
What type of compound is expected to have the largest dipole movement? - CORRECT ANSWER a bent compound
The boiling point of H2O, compared with other members of the series can be explained by - CORRECT ANSWER hydrogen bonding
How do you calculate formal charge? - CORRECT ANSWER (#of valence electrons) - (nonbonding electrons) - (bonding electrons / 2)
a triple bond is made up of - CORRECT ANSWER 2 pi bonds
1 sigma bond
a double bond is made up of - CORRECT ANSWER 1 sigma
1 pie
What is the molar volume of a gas? - CORRECT ANSWER 22.4 L
If a 17.0g of impure Ni+ metal reacts with excess carbon monoxide, CO, forming 6.25 L of Ni(CO)4 gas under standard temperature and pressure conditions, what is the percent by mass of Ni+ in impure nickel metal sample?
What do you start the stoich equation? - CORRECT ANSWER 6.25 L Ni(CO)4
When rounding to 3 sig figs, if you have a number that is .9647 - CORRECT ANSWER
What is the main gas law equation? - CORRECT ANSWER PV=nRT
(pressure x volume) =
What is the equation for Pressure? - CORRECT ANSWER Force/Area
Gas Law: Temperature-Volume relationship, at constant pressure. What is the constant for Charle's Law? - CORRECT ANSWER V/T = constant
Gas Law: Pressure-Volume relationship, at constant temperature. Boyle's Law - CORRECT ANSWER PV = constant
Gas Law: Pressure- Temperature relationship, at constant volume. Gay-Lusaacs' Law - CORRECT ANSWER P/T = constant
Temperature in Gas Law equations must be in what type of measurement? What is the conversion? - CORRECT ANSWER Must be in Kelvin
273.15 + C = K
P1V1 will always equal________ if temperature and particle numbers are constant - CORRECT ANSWER P2V2
1 atm = ? kPA? - CORRECT ANSWER 101.325
What does R equal when dealing with meters/mol K
(m^3/mol) - CORRECT ANSWER 8.3145
What does R equal when dealing with Liters kPA/mol K
(L/mol K) - CORRECT ANSWER 8.3145
What does R equal when dealing with Liters atm/ mol K - CORRECT ANSWER .082
Solubility: NO3- - CORRECT ANSWER Nitrate is soluble
Solubility: C2H3O2 - CORRECT ANSWER Methyl carbonate is soluble
Solubility of Cl- Br- I- - CORRECT ANSWER Soluble except in Ag2+, Pb2+, Hg2+
Solubility of SO4 2- - CORRECT ANSWER Sulfate is soluble except in Sr2+, Hg2+, Ba2+, Pb2+, Ca2+
Solubility of OH- and O2- - CORRECT ANSWER Hydroxide and Peroxide are insoluble except with alkali metals, Ca2+, Sr2+, Ba2+
Solubility of PO4 3- - CORRECT ANSWER Phosphate is insoluble EXCEPT with NH4+ and alkali metals
(Ammonium, and Group 1 metals)
Solubility of CO 3- - CORRECT ANSWER Carbonate is insoluble EXCEPT with NH4+ and alkali metals
(Ammonium, and Group 1 metals)
Solubility of SO3 2- - CORRECT ANSWER Sulfite is insoluble EXCEPT with NH4+ and alkali metals
(Ammonium, and Group 1 metals)
Solubility of S 2- - CORRECT ANSWER Sulfur is insoluble EXCEPT with NH4+, alkali metals,
(Ammonium, Group 1)
2 electron domains results in what type of hybridization? - CORRECT ANSWER sp
6 electron domains results in what type of hybridization? - CORRECT ANSWER Sp3d2
reaction in which electrons are transferred from one reactant to the other - CORRECT ANSWER redox reactions
Assigning Oxidation Numbers Rules (3) - CORRECT ANSWER 1. all elements in elemental form have an oxidation # of zero
2. For a monotonic ion the oxidation number equals the charge on the ion
3. The sum of the oxidation numbers in a molecule will equal the charge on the molecule
Assigning Oxidation Number Rule Exceptions - CORRECT ANSWER Oxygen = -2 except in Peroxide = -1
Hydrogen = +1 when with nonmetal -1 when with metal
Halogens are -1 except when with Oxygen while Fluorine is ALWAYS -2
What does the Reducing Agent do in a redox reaction? (aka the Reductant) - CORRECT ANSWER gives away an electron. Becomes oxidized
What does the Oxidizing Agent do in a redox reaction?
(aka the oxidant) - CORRECT ANSWER gains an electron. Becomes reduced
What is the molecular weight? - CORRECT ANSWER the sum of the mass of each element
Cannot be observed without changing the identity & composition of a substance - CORRECT ANSWER chemical property
Can be observed without changing the identity & composition of a substance - CORRECT ANSWER Physical property (color, density, melting point) all intensive. do not depend on amount of substance e
measure force of gravity of an object - CORRECT ANSWER weight
measure of how much matter an object contains - CORRECT ANSWER mass
α-particles
β-particles
γ-rays - CORRECT ANSWER 2+ elementary charge
1- elementary charge
uncharged
Who discovered the nucleus by observing the scattering of α-particles off of a thin gold foil & discovered the proton by bombarding N2 with α-particles. - CORRECT ANSWER Rutherford
Thompson discovered the Plum Pudding Model - what was that? Who proved him wrong? - CORRECT ANSWER stated that nucleus was a scattered positive sphere with electrons embedded in it, was proved wrong by Rutherford who did the gold foil experiment
Who discovered the proton? - CORRECT ANSWER Rutherford by bombarding N2 with alpha particles
Describe the atom. What makes up the nucleus and where do electrons reside - CORRECT ANSWER Protons and neutrons form the small, dense nucleus; electrons are found in a diffuse cloud around the nucleus; most of the volume of an atom is empty space.
How did Thompson discover the Electron? - CORRECT ANSWER by cathode
What are rows
What are columns - CORRECT ANSWER periods are rows
groups of columns
poor conductors, brittle - CORRECT ANSWER nonmetal
Bond formed from: metal+nonmetals - CORRECT ANSWER ionic bond
bond formed from: two nonmetals - CORRECT ANSWER molecular compound
How do you calculate Molarity - CORRECT ANSWER mol/L
What does a neutralization reaction occur between? What does it result in? - CORRECT ANSWER strong acid + base
H2O
Which type of compound has a higher melting point? - CORRECT ANSWER ionic compounds have higher melting points that molecular compounds
Energy is required to - CORRECT ANSWER break a bond
Energy is released when - CORRECT ANSWER a bond forms
Define Bond Polarity - CORRECT ANSWER Electrons will spend most of their time around the most electronegative atom
δ+ goes over the ____________ and δ- over
the ___________ atom - CORRECT ANSWER electropositive, electronegative
an electronegativity difference ≥ 1.7 indicates an
________ (sometimes you see 2.0 instead of 1.7).
An electronegativity difference ≤ 0.5 is generally considered ___________. If it is somewhere in the middle it is considered ________ - CORRECT ANSWER ionic
nonpolar
polar
Electronegativity periodic trend - CORRECT ANSWER electronegativity is greater the higher up on the right of the periodic table
Define electropositive atoms. Where are they located - CORRECT ANSWER smallest value, least electronegative. Located bottom left of periodic table
An ionic bond is stronger (i.e. the lattice energy is more negative) if: - CORRECT ANSWER 1) The charge on the individual ions is greater
2) The distance between + and - charge is less (smaller ions)
the energy released when one mole of an ionic
solid is formed from gaseous ions.
Measures the strength of an ionic bond - CORRECT ANSWER Lattice energy
Why are lattice energies listed as positive values instead of negative values? - CORRECT ANSWER This represents the energy needed to break
apart one mole of substance, rather than the energy released when the substance forms.
A solution will conduct electricity if it contains what? - CORRECT ANSWER dissolved ions
The ______ is dissolved in the _______ - CORRECT ANSWER solute
solvent
a substance that produces ions when dissolved in solution. - CORRECT ANSWER an electrolyte
What is the equation for dilution - CORRECT ANSWER (moles solute before dilution) = (moles solute after dilution)
C1V1 = C2V2
The _____ is titrated with the ______ - CORRECT ANSWER titrand
titrant
an analytical technique to determine the concentration of a solute. - CORRECT ANSWER Titration
Has two ionizable protons (H2SO4) - CORRECT ANSWER Diprotic acid
contains less dissolved solute than a saturated
solution at that temperature - CORRECT ANSWER unsaturated solution
contains more dissolved solute than a saturated solution at that temperature. - CORRECT ANSWER supersaturated solution
What is one weak base you should memorize - CORRECT ANSWER NH3 (ammonia)
List the 7 strong acids - CORRECT ANSWER HCl - hydrochloric acid
HBr - hydrogen bromide
HI - hydrogen iodide
HClO3 - Chloric acid
HClO4 - Perchloric acid
HNO3 - Nitric acid
H2SO4 - Sulfuric acid
What do neutralization reactions take place in - CORRECT ANSWER acid + base leaving salt + water
The strong bases are what? - CORRECT ANSWER soluble group 1
group 2
metal hydroxides
Acids increase the concentration of what?
Bases increase the concentration of what? - CORRECT ANSWER H+
OH-
What type of bond has a low conductivity as a solid but a high conductivity when fused? - CORRECT ANSWER ionic Ex: NaCl
What does a high vapor pressure value indicate - CORRECT ANSWER lower heats of vaporization
lower boiling points
less surface tension
What does a low vapor pressure value indicate
(little tendency to change from liquid to gas) - CORRECT ANSWER higher heat of vaporization
higher boiling points
high surface tension
equal volumes of gas under the same temperature and pressure will have...? - CORRECT ANSWER the same amount of molecules (avagondros)
What effects the vapor pressure of a liquid - CORRECT ANSWER temperature
specific heat formula - CORRECT ANSWER
formula for q - CORRECT ANSWER
What is ∆G when
+∆H and +∆S
and will the reaction occur? - CORRECT ANSWER +∆G at low temperatures
-∆G at high temperatures
rxn will occur at high temperatures
What is ∆G when
+∆H and -∆S
and will the reaction occur? - CORRECT ANSWER +∆G
rxn will never occur
What is ∆G when
-∆H and +∆S
and will the reaction occur? - CORRECT ANSWER -∆G
rxn will occur at any temperature
What is ∆G when
-∆H and -∆S
and will the reaction occur? - CORRECT ANSWER -∆G at low temperatures
+∆G at high temperatures
wil occur at low temperatures
if a reaction is carried out in a series of steps, ΔH for the reaction equals the sum of enthalpy changes for the individual steps. - CORRECT ANSWER Hess's Law
What are the Hess Law rules - CORRECT ANSWER - If you reverse the direction of a reaction then reverse the sign of ΔH.
- If you change the stoichiometry of a reaction (by multiplying all stoichiometric coefficients by some constant value), then multiple ΔH by this same value.
- When summing thermochemical equations, species in the reactants and products only cancel out if they are the exact same chemical as the exact same phase of matter.
Periodic Trends - CORRECT ANSWER
Atomic/ionic radii periodic trend - CORRECT ANSWER largest is on the bottom left
What isIonization energy, and what is its periodic trend - CORRECT ANSWER the amount of energy required to remove an electron from ground state
largest amount energy is top right
What is Electron affinity, and what is its periodic trend - CORRECT ANSWER the potential energy change when and electron is added to a gaseous atom or ion
the more negative, the more energy released
most negative at top right
1 L - CORRECT ANSWER = 1 dm^3
1000 mL
Formula for Density - CORRECT ANSWER
How many calories are in 1 kcal - CORRECT ANSWER 1000 cal
How many Joules in 1 calorie - CORRECT ANSWER 4.184
What type of element tends to gain electrons - CORRECT ANSWER nonmetals
What type of element tends to lose electrons - CORRECT ANSWER metals
Phrase to remember greatest wavelength/least frequency to smallest wavelength/greatest frequency - CORRECT ANSWER Rain Makes Igloos Very Unstable - Xtra Gay
radio - microwave - infared - visible - UV - xray - gamma
List one weakness of the Bohr model - CORRECT ANSWER Only orbits of specific radii are permitted for the electron in a hydrogen atom.
What does a dz2 orbital look like? - CORRECT ANSWER
What does a dxy orbital look like - CORRECT ANSWER
What does a dx2-y2 orbital look like - CORRECT ANSWER
What is effective nuclear charge and what is its periodic trend - CORRECT ANSWER how tightly electrons are held
greatest in bottom right.
Which are larger - cations or anions - CORRECT ANSWER cations (+)
What does an element need to have to be paramagnetic - CORRECT ANSWER one or more unpaired electrons
Lone PAIRS of electrons, lone electrons. know the difference - CORRECT ANSWER 2 e = 1 pair
2 e = 2 e
When resonance structures are shown, the real structure is actually an - CORRECT ANSWER average of all of them
What is the formula for ∆G? - CORRECT ANSWER ∆G = ∆H-T∆S
Consider this equation at constant temperature and volume
2SO2 (g) + O2 (g) ->equilibrium-> 2SO3 (g)
What is the effect of removing some SO3 from a system initially at equilibrium - CORRECT ANSWER The concentration of SO2 decreases more than O2
PCl5 ->equilibrium-> PCl3 + Cl2
what will cause an equilibrium shift to the right - CORRECT ANSWER the removal of Cl2
heat + CaSO3 ->equal-> CaO + SO2
what will cause an increase in pressure when equilibrium is reestablished? - CORRECT ANSWER increasing the reaction temperature
the numerical value of the equilibrium constant for any chemical change is effected by changing the what - CORRECT ANSWER the temperature
heat + C + CO2 ->equil-> 2CO
if pressure is increased but temperature is kept constant, what will be the result? - CORRECT ANSWER CO will decrease
C and CO2 will increase [Show Less]