Chem Final
How many moles of Na+ ions are in 100 mL of .2 M Na3PO4?
.0600 mol
How many carbon atoms are contained in 28 grams of C2H4? (2/5)
1.2x10^24
what is the concentration of Cl- in the solution? (1/4)
1M
which of the following electron configurations is consistent with the Spectrum? (1/2)
1s2 2s2
Which of the following ground-state electron configurations represents the atom that has the highest first ionization energy? (2/5)
1s2 2s2 2p6
Based on the half reactions, what is the coefficient for Al is the equation for the oxidation reduction reaction is balanced with the smallest whole number coefficients?
2
the partial pressure of argon is (3/5)
2 atm
what mass of HF is produced by the reaction of 3x10^23 molecules of H2 with excess F2?
20 g
after one of the reactants has been totally consumed, how many moles of HCL have been produced? (3/5)
20 mol
how many protons neutrons and electrons are in 56 26 Fe atom? (1/4)
26, 30, 26
an oxidation-reduction reaction that is also a synthesis reaction (3/5)
2Mg(s) + O2(g) --> 2MgO(s)
In this system the strongest base is
CO3 2-
then the solution represented in vessel 2 could be an aqueous solution of
CaCl2 with twice the molarity
which of the following correctly identifies the species associated with peak x and provides a valid justification? (1/3)
Ca^2+, because it's nucleus has two more protons
the lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions smallest? (1/2)
Cs+ and Br-
In the diagram above which of the labeled Arrow identifies hydrogen bonding in water? **
D (O bonded to other H)
which of the following graph shows the speed distribution of the same molecules at a lower temperature?
D (dashed curve is higher)
which of the following diagram shows the correct representation of the hydrogen bonding between thymine and adenine base pairs?
D (forms octagon)
Forms monatomic ions with 1- charge in solutions. (2/5)
F
which gas has the greater molar mass? (1/2)
Gas A
which pair of formulas includes the two most likely formulas of these oxides? (1/5)
GeO and GeO2
Based on the data in the graph, which of the following correctly identifies the diatomic molecules X2 Y2 Z2? (1/3)
H2, N2, O2
which of the following represents a Bronsted-Lowry conjugate acid base pair?
HC2O4- and C2O4 2-
Which of the following observations would provide evidence that the spectrum is consistent with the atomic model of the element? (1/2)
In its compounds... +3
Which of the following correctly indicates whether the solid represented by the particulate model shown to the left conducts electricity and explains why or why not? (3/4)
It does not conduct electricity because it's ions cannot move freely within the solid
Steel is an alloy containing Fe atoms and C atoms. Which of the following diagrams represents the particle level structure of Steel? (1/2)
Large Circle = Fe, small circle = C
the compound most likely formed with magnesium, Mg, is (1/4)
MgX
Which of the following could be the identity of a white crystalline solid that exhibits the following properties?
NaOH
atoms of which element are reduced in the reaction above? (1/2)
O in Na2O2
When placed in order of increasing ionization energy, what is the correct order for the species O, O+, O-? (1/5)
O-, O, O+
which of the following molecules has a dipole moment? **
PF3
which of the following is the correct net ionic equation for the reaction?
Pb2+ + 2Br-
In which of the following groups are the three species isoelectronic? (2/5)
S2-, K+, Ca2+
consider atoms of the following elements. Assume that the atoms or in the ground state. The atom that contains exactly three unpaired electrons is (3/4)
Sb
In the reaction represented above, what is the hybridization of the C atoms before and after the reaction occurs? (1/3)
Sp2, sp3
The BF3 molecule is nonpolar, whereas the NF3 molecule is polar. which of the following statements accounts for the difference in polarity of the two molecules? (1/4)
Unlike BF3, NF3 has a nonpolar geometry
Two different ionic compounds each contain only copper and chlorine. Both compounds are powders, one white and one brown. Elemental analysis is performed on each powder. Which of the following questions about the compound is most likely to be answered by the results of the analysis? (1/4)
What is the formula unit of each compound?
Which of the following best helps explain why the electronegativity of Cl is less than that of f? (2/5)
When CL and F form bonds with other atoms
Which will yield the greatest mass of CO2?
benzene
the exothermic process represented above is best classified as a (1/2)
chemical change because covalent
the electrons pair in a CF Bond could be considered (3/5)
closer to F
which of the following would be the best way to decrease the distance that the products travel up the plate
decrease
the equilibrium vapor pressure of C2H5OH at 300K is
lower, because London dispersion
What can be concluded above X and Y based on the experimental results?
y is more polar than x 1
which of the following Lewis diagrams best represents the bonding in the N2O molecule considering formal charges? (2/3)
N with one lone pair, triple bond, N, single bond, O with 3 lone pairs
which of the following has a bond order of 3? (2/5)
N2
Which of the following has an incomplete octet and in its Lewis structure? (3/5)
NO
which gas will condense at the lowest pressure?
butane
which of the following is not a valid resonance structure for N3-? **
double bond, single bond
which of the following describes the changes in the forces of attraction that occur as H2O changes phase from a liquid to a vapor?
hydrogen bonds
What is the partial pressure of He if the total pressure in the container is 6 atm?
5 atm
Which diagram provides a better particle representation for the solubility of o2 in H2O and why?
diagram 2 because polar H2O
Lewis electron dot diagrams for CO2 and SO2 are given above. The molecular geometries and polarity of the two substances are (2/3)
different because the lone pair
Which of the following best describes the intermolecular forces of attraction between water and benzene?
dipole induced dipole and London dispersion
according to the balanced equation above, how many moles of ClO2- are needed to react completely with 20 mL of 2M KMnO4 solution? (1/2)
0.030 mol
how many resonance structures can be drawn for O3?**
2
choose the electron dot formula that most accurately describes the bonding in CS2. **
2 double bonds, C in the middle
what is the total number of moles of reactants consumed when 1 mol of CO2 is produced?
2 mol
What is the final pressure in the vessel after the reaction is complete and the contents of the vessel are returned to 600k? (3/5)
3Pi
The ground state configuration of Ni 2+ is which of the following? (2/5)
3d8
copper atoms and zinc atoms have the same atomic radius, 135 picometers. based on this information, which of the following diagrams best represents an alloy containing only copper and zinc atoms? (1/4)
5x5 of circles with nothing else
over what volume range should the student collect the distallate of the compound with the weakest intermolecular forces?
B (first constant)
Which of the following laboratory setup is most appropriate for the student to use in order to separate and collect a substantial sample of each of the two hydrocarbons?
B (one with flame_
which of the gases, He or Ne, will escape faster through the pinhole and why? (1/4)
He will escape faster, higher average speed
based on the diagram above which of the following best helps explain why MGO is not able to conduct electricity but MGO is a good conductor of electricity? **
MgO consists of separate... held in a fixed lattice
Which of the following best explains this difference? (1/4)
More moles of ions are present
which of the following atoms cannot exceed the octet rule in a molecule? (3/5)
N
Which has a greater Bond length, NO2- or NO3-? (3/5)
NO3-
which of the diagrams below is the best particle representation of the mixture after the precipitation reaction occurred? (1/2)
Na+ and NO3- floating unattached, Ag+ and Cl- in precipitate touching bottom
which of the following is most likely to be a solid at room temperature?(1/2)
Na2S
which of the following most likely cause the error in the point of student plotted at .050M? **
distilled water in cuvette
A student obtains a sample of a pure solid compound. In addition to Avogadro's number, which of the following must the student know in order to determine how many molecules are in the sample? (1/4)
molar mass of the compound, mass of the sample
the elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from an C&Se is most likely to be true? (3/4)
nonpolar covalent
which of the following represents a general electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the second and third ionization energies? (1/4)
ns2
the reaction is correctly classified as which of the following ppes?
oxidation-reduction
which of the following complete Lewis diagram represents a molecule containing a bond angle that is closest to 120 degrees?(1/2)
the linear one, c bonded to two o's
based on the concepts of polarity and hydrogen bonding, which of the following sequences correctly lists the compounds above in the order of their increasing solubility in water
x, y, z
which of the following best represents the contents of the box after the reaction has proceeded as completely as possible? **
B (4 pairs, 1 of 2 white balls)
Which of the following correctly identifies which has the higher first ionization energy, Cl or Ar, and supplies the best justification? (1/5)
Ar because of its higher effective nuclear charge
a 15.5 g sample of a compound contains 6 g of C, 1.5 g H, and 8 g O. which of the following is an empirical formula of the compound? (1/4)
CH3O
the Mass Spectrum of the element SB is most likely represented by which of the following? (1/2)
D, high at 121 and 123
Atoms of K combine with atoms of f to form a compound. Atoms of which of the following elements combine with atoms of f in the same ratio? (1/2)
Li
which of the following atoms or ions has exactly two unpaired electrons? (2/5)
Zr2+
which electron in Sulfur is least shielded from nuclear charge? (2/5)
an electron in the 1s orbital
the best explanation for the observation is that the molecules of the gas (1/4)
are attracted to each other and do not exert
at constant temperature, the behavior of a sample of a real gas more closely approximates that of an ideal gas as the volume of the container is increased because the (3/5)
average distance between molecules becomes greater
The ionization energies for an element are listed below, based on the table above, the element is most likely (1/5)
boron
which of the following statements provides the best prediction for the boiling point of NaCl?
lower boiling point
those observations provide evidence that under the given conditions (3/5)
forces among the Br2 molecules are stronger than those among the C2 molecules
Which of the following is true of the halogens When comparing them to other elements in the same period? (1/5)
higher ionization energy
Two pure elements react to form compounds. What element is an Alkali metal x and the other element is a halogen Z. Which of the following is the most valid scientific claim that can be made about the compound? (3/4)
it contains ionic bonds
if the temperature of the system remains constant, which of the following statements about the partial pressure of gas X is correct
it depends on relative molecular masses
The average kinetic energy of the gas molecules is
same
Which of the following correctly compares the two samples in terms of their deviation from ideal gas behavior and explains why?
sample 2 because Xe atoms
which of the following results would be evidence that a chemical reaction took place?
temperature
which of the following is correct?
the amount of OF2 produced is halved
which of the following is true regarding the force between the atoms when their internuclear distance is X? (2/5)
the attractive and repulsive forces are balanced
which of the following scientific claims about the bond in the molecular compounds in HF is most likely to be true? (1/2)
the bond is highly polar
on the basis of Coulomb's law, which of the following best helps to explain the large difference between the lattice energies of NaF and MgF2? (2/3)
the charge of the Mg cation
