Chem 110 Exam 2

Which bond is least polar? C-N C-O C-C Correct C-Cl C-F

C-C

Which bond is the MOST polar? C-N C-C C-Cl C-F

C-F

Which is NOT an ionic compound? KCl Ca(NO3)2 CBr4 Correct AlBr3 All of the choices are ionic compounds.

CBr4

Carbon tetrachloride was used as a dry cleaning agent until it was recognized that long-term exposure caused negative effects to the liver and kidneys. Which formula would be named carbon tetrachloride? CCl C4Cl CCl4 Correct CCl3 C3Cl

CCl4

Which of the following molecule(s) is(are) polar? CO2 CH4 CBr4 CHBr3 More than one of the molecules are polar.

CHBr3

Which of the following molecules contains more than one double bond in its Lewis structure? CS2 Correct C2H2 HCN CH3OCH3 N2H2

CS2

What is the ion symbol for an atom with twenty (20) protons and eighteen (18) electrons? Ca Ca2+ Correct Ar Ar2+ Ar2-

Ca2+

What is the formula for chromous cyanide? CrCN Cr(CN)2 Cr(CN)3 Cr2CN Cr2(CN)3

Cr(CN)2

Covalent bonds result from the ________ electrons between two atoms. transfer of equal sharing of unequal sharing of Transfer of, equal sharing of, and unequal sharing of are correct. Equal sharing of and unequal sharing of are correct

Equal sharing of and unequal sharing of are correct

Which chemical formula is correct? Ag(CH3CO2)2 K2CN Mg(OH)2 MgHCO3 More than one of the formulas are correct.

Mg(OH)2

Which of the following compounds is not classified as covalent? CH4 SF6 PBr3 MgCl2 None of the choices are correct.

MgCl2

What is the formula for the ionic compound formed when magnesium and oxygen combine? MgO Correct MgO2 Mg2O Mg2O2 Mg2O6

MgO

What is the chemical formula for dinitrogen tetroxide? N4O2 O4N2 N2O4 Correct O2N4 NO2

N2O4

Which choice would be named dinitrogen pentoxide?

N2O5

Which of the following molecules will not contain a multiple bond in its Lewis structure? CS2 C2H2 NCl3 Correct CH2O CO2

NCl3

Which chemical formula is NOT correct? Na2HCO3 Correct NaNO3 Na2HPO4 Na2SO3 More than one of the formulas are not correct.

Na2HCO3

Which is NOT a covalent compound? Br2 NO2 NH3 NaNO2 More than one of the compounds is not a covalent compound.

NaNO2

Which of the diatomic molecules shown below contains a double bond? N2 O2 Correct HCl Br2 F2

O2

What is the ion symbol of the oxide ion? O2- Correct O22- O2 O2+ O6-

O2-

Which atom from the list below would create the MOST polar bond with nitrogen? C O P Correct Se Br

P

The diphosphate ion is a biologically important polyatomic ion. If the ionic compound calcium diphosphate has the formula Ca2P2O7, which correctly represents the ion symbol of the diphosphate ion? P2O72- PO4- 2 PO46- P2O74-​ P2O71-

P2O74-​

Which molecule fits the characteristics described: has trigonal planar geometry; contains three polar bonds; all the dipoles reinforce? BCl3 PH3 Correct CH2O CCl4 H2S

PH3

What is the formula for the ionic compound formed from the lead (II) ion and the carbonate ion? Pb(CO3)2 PbCO3 Pb2CO3 PbCO4 Pb2(CO3)2

PbCO3

Which atom has the lowest electronegativity? Al S Se Rb Correct F

Rb

What is the ion symbol for an atom with sixteen (16) protons and eighteen (18) electrons S2- Correct S Ar Ar2+ Ar2-

S2-

What is the ion symbol for an atom with sixteen (16) protons and eighteen (18) electrons? S2- S Ar Ar2+ Ar2-

S2-

Which of the molecules is incorrectly paired with the molecular shape listed BF3 - trigonal planar H2S - bent CO2 - linear CBr4 - tetrahedral SO3 - trigonal pyramidal

SO3 - trigonal pyramidal

What is the correct chemical formula of selenium dioxide? SO2 SeO2 Se2O OS2

SeO2

What is the chemical formula of tin (IV) cyanide? Sn4CN SnCN4 Sn(CN)4 Correct SnC4N4 Sn4(CN)4

Sn(CN)4

Consider the B atom and the B+ ion. Which will have the larger radius (is larger in size)? the B+ anion the B+ cation the B atom Correct They will both have identical radii. Cannot be determined from the information provided.

The B Atom

The Lewis structure shown below is not a valid Lewis structure. What statement best describes the error in the structure? The nitrogen atoms violate the octet rule. The chlorine atoms violate the octet rule. The structure contains an incorrect number of valence electrons. Correct Chlorine atoms and nitrogen atoms do not typically form bonds with each other. Nitrogen never forms double bonds.

The structure contains an incorrect number of valence electrons.

Which of the statements concerning chemical bonds is false? The sharing of electrons between two nonmetal atoms results in a covalent bond. The attraction between oppositely charged ions results in an ionic bond. The term nonpolar is used to describe a covalent bond in which electrons are not shared equally. A bond dipole is the separation of charge that results when atoms sharing electrons have different electronegativities. Chemical bonding occurs only when atoms share valence electrons to achieve stability.

The term nonpolar is used to describe a covalent bond in which electrons are not shared equally.

Which of the statements concerning chemical bonds is false? The sharing of electrons between two nonmetal atoms results in a covalent bond. The attraction between oppositely charged ions results in an ionic bond.Incorrect The term nonpolar is used to describe a covalent bond in which electrons are not shared equally.Correct A bond dipole is the separation of charge that results when atoms sharing electrons have different electronegativities. Chemical bonding occurs only when atoms share valence electrons to achieve stability.

The term nonpolar is used to describe a covalent bond in which electrons are not shared equally.

Which of the following statements regarding bonding is TRUE? In order to create a stable compound, atoms must share valence electrons. In order to create a stable compound, atoms must gain or lose valence electrons. In covalent bonding, a metal and a non-metal share valence electrons. In ionic bonding, two nonmetals share valence electrons. To create stable compounds, atoms must transfer or share valence electrons.

To create stable compounds, atoms must transfer or share valence electrons.

The Lewis structure of formaldehyde is shown below. Which statement concerning this structure is INCORRECT?

Two electrons are being shared between the carbon atom and the oxygen atom.

If atoms with the electron-dot symbols shown below are combined, what is the formula of the ionic compound that is formed? .. X. .Y. '' XY X2Y Correct XY2 X2Y2 X3Y2

X2Y

What is the correct formula for the ionic compound formed from the cation X3+ and the anion Y2- that results in zero overall charge? X2Y3 X2Y X3Y2 XY3 XY

X2Y3

If atoms with the electron-dot symbols shown below are combined, what is the formula of the ionic compound that is formed? (# is dots) X2 Y6 XY X2Y XY2 X2Y2 X3Y2

XY

What is the general formula when calcium and nitrite ions form an ionic compound? XY X2Y XY2 XY3 X2Y3

XY2

What is the name of compound (NH4)2SO4? ammonium sulfide ammonia sulfate ammonia sulfoxide ammonium sulfate diammonium sulfate

ammonium sulfate

Which roman numeral correctly completes the name of the compound CrO? chromium oxide chromium (I) oxide chromium (II) oxide Correct chromium (III) oxide chromium (IV) oxide

chromium (II) oxide Correct

What is the proper name for CuCl? copper chloride copper (I) chloride copper (II) chloride copper monochloride monocopper monochloride

copper (I) chloride

What is the proper name for CuCl? copper chloride copper (I) chloride Correct copper (II) chloride copper monochloride monocopper monochloride

copper (I) chloride

Which of the following is classified as a group in the valence shell electron pair repulsion (VSEPR) theory? an atom a lone pair of electrons a valence electron either an atom or a valence electron either an atom or a lone pair of electrons

either an atom or a lone pair of electrons

The correct name for AuI3 is ________ silver iodide gold iodide gold (III) iodide gold iodide (III) silver triiodide

gold (III) iodide

Which of the following elements will generally form only one covalent bond? sulfur carbon hydrogen argon nitrogen

hydrogen

When forming ions, metals typically do which of the following? lose electrons to form negatively charged ions gain protons to form cations gain electrons to form anions lose electrons to form positively charged ions Correct share electrons for form molecules

lose electrons to form positively charged ions

Ionic bonds form between metals and non-metals Correct two metals two nonmetals

metals and non-metals

Which atom(s) in the structure below has(have) a partial negative charge (δ-)? carbon fluorine hydrogen nitrogen nitrogen and fluorine

nitrogen and fluorine

Identify the correct name for the compound NO2 which is a red-brown colored air pollutant that results from the burning of fuel. nitrogen oxide dinitrogen monoxide nitrogen dioxide Correct nitrogen oxate nitrate

nitrogen dioxide

The correct name for Ag2O is ________ silver oxide Correct silver (I) oxide silver (II) oxide disilver oxide silver dioxide

silver oxide

What is the name of the SO42- ion? sulfide ion sulfate ion Correct sulfite ion bisulfate ion sulfoxide ion

sulfate ion

What is the molecular shape around the phosphorus atom in PH3? linear bent trigonal planar tetrahedral trigonal pyramidal

trigonal pyramidal

Estimate the bond angles around the sulfur atom in the structure shown below. 90° ~109.5°Correct 120° 180°

~109.5°

Which bond has the polarity incorrectly labeled? δ+ H-Cl δ- δ+ O-C δ- δ+ Cl-F δ- δ- Cl-Br δ+ δ- F-O δ+

δ+ O-C δ-

The covalent bond between chlorine and iodine is a polar one. Which of the following properly represents the direction of polarity in this bond? δ+ Cl-I δ- δ- Cl-I δ+ + Cl-I - - Cl-I +

δ- Cl-I δ+

What is the charge on the nickel ion in the compound NiCl2? +1 +2 +3 +4

+2

An atom has the electron-dot symbol shown below. If this atom is a main group element, what charge will it form in its ionic state? X3 -1 +3 -5 -3 +5

+3

What is the charge on the chromium ion in the ionic compound CrCl3? +6 +3 -3 -6 not enough information is given to determine the charge

+3

How many covalent bonds are present in the organic molecule propane (CH3CH2CH3)? 3 5 8 10 Correct 12

10 (count the lines)

What is the charge of the ions formed by group 7A elements? +1 +7 -1 -7 Elements in Group 7A do not form ions

-1

How many valence electrons are in a molecule of formaldehyde (CH2O)?

12 use the chart

What is the charge of the ions formed by group 7A elements? +1 +7 -1 Correct -7 Elements in Group 7A do not form ions.

-1 Charge

Acetaldehyde is a carcinogenic chemical that the body produces when it breaks down alcohol. How many polar bonds are in the acetaldehyde structure shown below? 0 1 Correct 3 4 5

1

Predict the bond angles around the carbon atom in the structure of carbonic acid shown below. Don't forget to draw in lone pairs where needed to give octets. 180° 120° Correct 109.5° 90° 60°

120°

The electronic configuration of the phosphorus atom is ________ and the electronic configuration of the phosphide anion is ________. 1s22s22p63s23p3; 1s22s22p63s23p6 1s22s22p63s23p3; 1s22s22p6 1s22s22p63s23p6; 1s22s22p63s23p3 1s22s22p63s23p6; 1s22s22p6

1s22s22p63s23p3; 1s22s22p63s23p6

How many protons and electrons are present in Co2+? 27 protons, 27 electrons 27 protons, 29 electrons 27 protons, 25 electrons 29 protons, 27 electrons 29 protons, 25 electrons

27 protons, 25 electrons

How many covalent bonds are generally formed by atoms with five valence electrons? 1 2 3 4 5

3

The term nonpolar is used to describe a covalent bond in which electrons are not shared equally.

6

How many total valence electrons does the polyatomic ion NH4+ possess? 8 9 10 11 7

8

How many total electrons are present in the polyatomic ion, hydrogen phosphate HPO42-? 30 32 80 82 Correct None of the choices are correct.

82

How many total electrons are present in the polyatomic ion, hydrogen phosphate HPO42-? 30 32 80 82

82

Aspartic acid is an amino acid used to synthesize proteins. How many lone pairs of electrons need to be added to complete the aspartic acid structure shown below? 4 6 8 9 11

9

Aspartic acid is an amino acid used to synthesize proteins. How many polar bonds are in the aspartic acid structure shown below?

9

Which statement concerning chemical bonds is FALSE? A covalent bond involves the sharing of electrons between two nonmetal atoms. An ionic bond is the attraction between oppositely charged ions. A nonpolar bond is a covalent bond in which electrons are not shared equally between the atoms. Correct Electronegativity is a measure of the attraction an atom has for the electrons it shares in a bond.

A nonpolar bond is a covalent bond in which electrons are not shared equally between the atoms.

What is the formula for the ionic compound formed when aluminum and sulfur combine? AlS Al2S3 Correct AlS3 Al2S Al3S2

Al2S3

Which compound is named INCORRECTLY? CBr4 - carbon tetrabromide SO3 - sulfur trioxide P2O4 - diphosphorus tetroxide N2O3 - dinitrogen trioxide AlCl3 - aluminum trichloride

AlCl3 - aluminum trichloride

Which statement best explains the basis for the octet rule? Atoms are most stable when they have eight bonds. Atoms lose, gain, or share electrons to become a stable, noble gas. All atoms are most stable with eight protons in their nucleus. All atoms are most stable with eight electrons in their valence shell and the electron configuration of a noble gas. All atoms are most stable with a completely filled valence shell and the electron configuration of a noble gas.

All atoms are most stable with a completely filled valence shell and the electron configuration of a noble gas

Which compound has the greatest number of valence electrons? H2S CH4 NH3 H2O all of the molecules have the same number of valence electrons

All of the molecules have the same number of valence electrons.

Which statement concerning resonance is FALSE? Resonance structures have the same arrangement of atoms, but different arrangements of electrons. Resonance stabilizes molecules by spreading the electrons over a larger region of space. All resonance structures represent accurate representations of the molecules they depict. Resonance structures can differ in the number of multiple bonds present. The true structure of the composite of all resonance structures is known as a hybrid.

All resonance structures represent accurate representations of the molecules they depict.

Which atom fits the electron-dot symbol shown below? Li B Correct N Na C

B

Which atom fits the electron-dot symbol shown below? X3 Li B N Na

B

Which element is more electronegative than sulfur? Si C Se P Br

Br

A diatomic molecule contains ________. I. atoms of two different elements bonded together with a covalent bond II. two atoms of the same element bonded together with a covalent bond III. two lone pairs of electrons

I or II only

Identify the incorrect statement regarding bond polarity. If a molecule contains no polar bonds, it is a nonpolar molecule. If a molecule contains one polar bond, it is a polar molecule. If a molecule contains more than one polar bond and the individual dipoles cancel, it is a nonpolar molecule. If a molecule contains more than one polar bond, it is a polar molecule. More than one of these statements are incorrect.

If a molecule contains more than one polar bond, it is a polar molecule.

Which of the following does not represent a physical property of all ionic compounds? Ionic compounds have high melting points. Ionic compounds are soluble in water. Correct Ionic compounds have high boiling points. Ionic compounds are crystalline solids at room temperature. Ionic compounds are held together by strong attractions between cations and anions.

Ionic compounds are soluble in water

Which of the following does not represent a physical property of all ionic compounds? Ionic compounds have high melting points. Ionic compounds are soluble in water. Ionic compounds have high boiling points. Ionic compounds are crystalline solids at room temperature.

Ionic compounds are soluble in water.

For an ionic compound with the formula of X2Y, if sulfur is represented by Y, which main group element can represent X? C Cu Al K Correct Ca

K

What is the formula for the ionic compound formed when potassium and bromine combine? PBr KBr PBr2 KBr2 K2Br

KBr

What is the formula for the ionic compound formed when potassium and bromine combine? PBr KBr Correct PBr2​ KBr2 K2Br

KBr

Which compound has the highest melting point? KCI CH4 C6H12O6 H2O PH3

KCI

Which statement concerning the ion Li+ is correct? Li+ has two total electrons. Correct Li+ has an octet of 8 electrons in its valence shell. Li+ is formed when a lithium atom gains one electron. Li+ is formed when a lithium atom gains one proton. Li+ is an anion.

Li+ has two total electrons.

What is the formula for the ionic compound lithium oxide? LiO LiO2 Li2O Correct Li2O2 LiO6

Li2O

What is the formula for the ionic compound lithium oxide? LiO LiO2 Li2O Li2O2 LiO6

Li2O

Which of the following compounds is classified as covalent? KCl LiBr HCl NaBr None of the choices are correct.

HCI

Considering the electronegativity values indicated for each element, which covalent bond is the LEAST polar? C Cl F O N H 2.5 3.0 4.0 3.5 3.0 2.1 C-N N-O F-F Correct H-Cl

F-F

In bonding, main group elements ________ to attain the electronic configuration of the noble gas closest to them in the periodic table. gain electrons lose electrons share electrons gain, lose, or share electrons

Gain, lose or share electrons

Which group of the Periodic Table does not typically form ions? Group 1A Group 2A Group 6A Group 7A Group 8A

Group 8A