Chemistry Final Exam timberlake
How many electrons are shared in a single covalent bond?
2
How many unshared pairs of electrons are in a molecule of hydrogen iodide?
3
What is the total number of covalent bonds normally associated with a single carbon atom in a compound?
4
How many valence electrons does iodine atom have?
7
A chemical formula for a molecular compound represents the composition of a. a molecule b. an atom c. the ions that make up the compound d. the crystal lattice
A
An ionic bond is a bond between -- a. a cation and an anion b. valence electrons and cations c. the ions of two different meals d. the ions of two different nonmetals
A
How many Cl⁻ atoms are present in 2.00 mol of KCl? a. 1.20 x 10²⁴ b. 6.02 x 10²⁴ c. 2.00 d. 0.5
A
If two covalently bonded atoms are identical, the bond is nonpolar a. nonpolar covalent b. polar covalent c. dipole covalent d. coordinate covalent
A
In a compound, the algebraic sum of the oxidation numbers of all atoms equals a. 0 b. 1 c. 8 d. the charge on the compound
A
Which of the following is true about the composition of ionic compounds? a. They are composed of anions and cations. b. They are composed of anions only. c. They are composed of cations only. d. They are formed from two or more nonmetallic elements.
A
A chemical formula includes the symbols of the elements in the compound and subscripts that indicate a. atomic mass of each element b. number of atoms or ions of each element that are combined in the compound c. formula mass d. charges on the elements or ions
B
A molecule with a single covalent bond is _____ a. CO₂ b. Cl₂ c. CO d. N₂
B
Aluminum is a group 3A metal. Which ion does Al typically form? a. Al³⁻ b. Al³⁺ c. Al⁵⁻ d. Al⁵⁺
B
A mutual electrical attraction between the nuclei and valance electrons of different atoms that binds the atoms together is called a(n) a. dipole b. Lewis structure c. chemical bond d. London force
C
How are bases named? a. like monatomic elements b. like polyatomic ions c. like ionic compounds d. like molecular compounds
C
How many electrons does nitrogen gain in order to achieve a noble-gas electron configuration? a. 1 b. 2 c. 3 d. 4
C
Most chemical bonds are a. purely ionic b. purely covalent c. partly ionic and partly covalent d. metallic
C
Write the formula for carbon tetrafluoride.
CF₄
Write the formula for carbon disulfide.₋
CS₂
A compound held together by ionic bonds is called a ___ a. diatomic molecule b. polar compound c. covalent molecule d. salt
D
A neutral group of atoms held together by covalent bonds is a a. molecular formula b. chemical formula c. polyatomic ion d. molecule
D
According to VSEPR theory, molecules adjust their shapes to keep which of the following as far apart as possible? a. pairs of valence electrons b. inner shell electrons c. mobile electrons d. the electrons closest to the nuclei
D
How many hydrogen atoms are in 5 molecules of isopropyl alcohol, C₃H₇O? a. 5 x (6.02 x 10²³) b. 5 c. 35 d. 35 x (6.02 x 10²³)
D
How many valence electrons are in an atom of phosphorous? a. 2 b. 3 c. 4 d. 5
D
Malleability and ductility are characteristic of substances with a. covalent bonds b. ionic bonds c. Lewis structures d. metallic bonds
D
The chemical formula for water, a covalent compound, is H₂O. This formula is an example of a(n) a. formula unit b. Lewis structure c. ionic formula d. molecular formula
D
The electrons involved in the formation of a chemical bond are called a. dipoles b. s electrons c. Lewis electrons d. valence electrons
D
The electrons involved in the formation of a chemical bond are called a. poles b. s electrons c. Lewis electrons d. valence electrons
D
What is the correct formula for potassium sulfite? a. KHSO₃ b. KHSO₄ c. K₂HSO₃ d. K₂SO₄
D
Which of the following is the name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecules? a. unbalanced pair b. outer pair c. inner pair d. unshared pair
D
Which of the following shows correctly an ion pair and the ionic compound the two ions form? a. Sn⁴⁺, N³⁻: Sn₄N₃ b. Cu²⁺, O²⁻: Cu₂O₂ c. Cr³⁺, I⁻: CrI d. Fe³⁺, O²⁻: Fe₂O₃
D
in drawing a Lewis structure, the central atom is generally the a. atom with the greatest mass b. atom with the highest atomic number c. atom with the fewest electrons d. least electronegative atom
D
Write the formula for nitrogen trifluoride.
NF₃
Write the formula for dinitrogen trisulfide.
N₂S₃
Write the formula for phosphorous mononitride.
PN
Write the formula for silicon dioxide
SiO₂
shapes adjust so valence-electron pairs are as far apart as possible
VSEPR theory
D
What is the correct Lewis structure for hydrogen chloride, HCl?
Produce a hydrogen ion when dissolved in water.
acid
Atom or group of atoms having a negative charge.
anion
Produces a hydroxide ion when dissolved in water.
base
Compound composed of two different elements.
binary compound
energy needed to break a single bond between two covalently bonded atoms
bond dissociation energy
molecular orbital that can be occupied by two electrons of a covalent bond
bonding orbital
What is the name of the covalent compound CO₂₄?
carbon dioxide
What is the name of the covalent compound CO?
carbon monoxide
Atom or group of atoms having a positive charge.
cation
The name for the CrO₄²⁻ ion is --
chromate
a covalent bond in which the shared electron pair comes from only one of the atoms
coordinate covalent bond
What is the name of the covalent compound N₂O₃?
dinitrogen trioxide
attraction between polar molecules
dipole interaction
A covalent bond in which two pairs of electrons are shared.
double covalent bond
A depiction of valence electrons around the symbol of an element
electron dot structure
An anion of chlorine or other halogen --
halide ion
a type of bond that is very important in determining the properties of water and of important biological molecules such as proteins and DNA
hydrogen bond
The force of attraction binding oppositely charged ions the attraction of vtogether --
ionic bond
In any chemical compound, the masses of elements are always in the same proportion by mass.
law of definite proportions
When two elements form more than one compound, the masses of one element that combine with the same mass of the other element are in the ratio of small, whole numbers.
law of multiple proportions
Consists of a single atom with a positive or negative charge.
monatomic ion
crystal in which all the atoms are covalently bonded to each other
network solid
What is the name of the covalent compound N₂?
nitrogen
What is the name of the covalent compound NP?
nitrogen phosphide
Atoms react so as to acquire the stable electron structure of a noble gas --
octet rule
a covalent bond between two atoms of significantly different electro negativities
polar bond
Tightly-bound group of atoms that behaves as a unit and carries a net charge.
polyatomic ion
symmetrical bond along the axis between the two nuclei
sigma bond
a covalent bond in which only one pair of electrons is shared
single covalent bond
A depiction of the arrangement of atoms in molecules and polyatomic ions
structural formula
109.5°
tetrahedral angle
An electron in the highest occupied energy level of an atom is called a --
valence electron
Which best explains the observation that metals are malleable and ionic crystals are brittle? a. their chemical bonds b. their London forces c. their enthalpies of vaporization d. their net charge
A
Which of the following compounds contains the lead(II) ion? a. PbO b. PbCl₄ c. Pb₂O d. P₂bS
A
Which of the following correctly represents an ion pair and the ionic compound the ions form? a. Ca²⁺, F⁻: CaF₂ b. Na⁺, Cl⁻: NaCl₂ c. Ba²⁺, O²⁻; Ba₂O₂ d. Pb⁴⁺, O²⁻: Pb₂O₄
A
Which of the following diatomic molecules is joined by a double covalent bond? a. O₂ b. Cl² c. N² d. He₂
A
Which of the following is true about the melting temperature of potassium chloride?Ba. The melting temperature is relatively high. b. The melting temperature is variable and unpredictable. c. The melting temperature is relatively low. d. Potassium chloride does not melt.
A
Which of the following show both the correct formula and correct name of an acid? a. HClO₂, chloric acid b. HNO₂, hydronitrous acid c. H₃PO₄, phosphoric acid d. HI, iodic acid
C
in drawing a Lewis structure, each nonmetal atom except hydrogen should be surrounded by a. 2 electrons b. 4 electrons c. 8 electrons d. 10 electrons
C
Which is a typical characteristic of an ionic compound? a. electron pairs are shared among atoms b. The ionic compound has a low solubility in water. c. The ionic compound is described as a molecule. d. The ionic compound has a high melting point.
D
What is the formula for phosphoric acid? a. H₂PO₃ b. H₃PO₄ c. HPO₂ d. HPO₄
B
Which of the following formulas represents an ionic compound? a. CS₂ b. BaI₂ c. N₂O₄ d. PCl₃
B
Metals are malleable because the metallic bonding a. holds the layers of ions in rigid positions b. maximizes the repulsive forces within the metal c. allows one plane of ions to slide past another d. is easily broken
C
Molecular compounds are usually ___________ a. composed of two or more transition elements b. composed of positive and negative ions c. composed of two or more nonmetallic elements d. exceptions to the law of definite proportions
C
Name the compound CF₄ a. calcium fluoride b. carbon fluoride c. carbon tetrafluoride d. monocalcium quadrafluoride
C
Name the compound Zn₃(PO)₂ -- a. zinc potassium oxide b. trizinc polyoxide c. zinc phosphate d. zinc phosphite
C
The chemical formula for an ionic compound represents the a. number of atoms in each molecule b. number of ions in each molecule c. ratio of the combined ions present in the sample total number of ions in the crystal lattice.
C
The molar mass of CCl₄ is 153.81 g/mol. How many grams of CCl₄ are needed to have 5.000 mol? a. 5 g b. 30.76 g c. 769.0 g d. 796.05 g
C
The substance whose Lewis structure shows three covalent bonds is a. H₂O b. CH₂Cl₂ c. NH₃ d. CCl₄
C
The substance whose Lewis structure shows three covalent bonds is a. H₂O₂ b. CH₂Cl₂ c. NH₃ d. CCl₄
C
What is the correct formula for barium chlorate? a. Ba(ClO₂ b. Ba(ClO₂)₂ c. Ba(ClO₃)₂ d. BaCl₂
C
What is the correct name for the N³⁻ion? a. nitrate ion b. nitrogen ion c. nitride ion d. nitrite ion
C
What is the formula for barium hydroxide? a. BaOH b. BaOH₂ c. Ba(OH)₂ d. Ba(OH)
C
What is the formula mass of MgCl₂? a. 46 amu b. 59.76 amu c. 95.21 amu d. 106.35 amu
C
What is the number of moles in 432 g Ba(NO₃)₂? a. 0.237 mol b. 0.605 mol c. 1.65 mol d. 3.66 mol
C
When Group 2A elements form ions, they ___ a. Lose two protons b. Gain two protons c. Lose two electrons d. Gain two electrons
C
When dissolved in water, acids produce _________ a. negative ions b. polyatomic ions c. hydrogen ions d. oxide ions
C
When one atom contributes both bonding electrons In a single covalent bond, the bond is called a(n)_______ a. one-sided covalent bond b. unequal covalent bond c. coordinate covalent bond d. ionic covalent bond
C
Which of the following compounds contains the Mn³⁺ ion? a. MnS b. MnBr₂ c. Mn₂O₃ d. MnO
C
what are shared in a covalent bond? a. ions b. Lewis structures c. electrons d. dipoles
C
What is the percentage composition of CO? a. 50% C, 50% O b. 12% C, 88% O c. 25% C, 75% O d. 43% C, 57% O
D
In which of the following are the symbol and name for the ion given correctly? a. Fe²⁺: ferrous ion; Fe³⁺⁺ ferric ion b. Sn²⁺, stannic ion; Sn⁴⁺, stannous ion c. Co²⁺, cobalt(II) ion; Co³⁺, cobaltous ion d. Pb²⁺, lead ion; Pb⁴°, lead(IV) ion
A
The atomic masses of any two elements contain the same number of a. atoms b. grams c. ions d. milliliters
A
The electrostatic attraction between positively charged nuclei and negatively charged electrons permits two atoms to be held together by a(n) a. chemical bond b. London force c. neutron d. ion
A
The greater the electronegativity difference between two bonded atoms, the greater the percentage of ______ in the bond. a. ionic character b. covalent character c. metallic character d. electron sharing
A
The octet rule states that, in chemical compounds, atoms tend to have ____ a. the electron configuration of a noble gas b. more protons than electrons c. eight electrons in their principal energy level d. more electrons than protons
A
To draw Lewis structure, one must know the a. number of valence electrons in each atom b. atomic mass of each atom c. bond length of each atom d. ionization energy of each atom
A
Use VSEPR theory to predict the shape of the carbon tetraiodide molecule, CI₄ a. tetrahedral b. linear c. bent d. trigional-planar
A
What characteristic of metals makes them good electrical conductors? a. They have mobile valence electrons. b. They have mobile protons. c. They have mobile cations. d. Their crystal structures an be rearranged easily.
A
What is basis of a metallic bond? a. the attraction of metal ions to mobile electrons b. the attraction between neutral metal atoms c. the neutralization of protons by electrons d. the attraction of oppositely charged ions
A
What is shown by the structural formula of a molecule or polyatomic ion? a. the arrangement of bonded atoms b. the number of ionic bonds c. the number of metallic bonds d. the shapes of molecular orbitals
A
What is the electron configuration of the calcium ion? a. 1s²2s²2p⁶3s²3p⁶ b. 1s²2s²2p⁶3s²3p⁶4s² c. 1s²2²s2p⁶3s²3p⁶4s¹ d. 1s²2s²2p⁶3s²
A
What is the formula for the compound formed by lead(II) ions and chromate ions? a. PbCrO₄ b. Pb₂CrO₄ c. Pb₂(CrO)₃ d. Pb(CrO)₂
A
Bonding in molecules or ions that cannot be correctly represented by a single Lewis structure is a. polyatomic b. resonance c. single bonding d. double bonding
B
If a material can be shaped or extended by physical pressure, such as hammering, which property does the material have? a. conductivity b. malleability c. ductility d. luster
B
If the atoms that share electrons have an unequal attraction for the electrons, the bond is called a. nonpolar b. polar c. ionic d. dipolar
B
In metals, the valence electrons a. are attached to particular positive ions b. are shared by all of the atoms c. are immobile d. form covalent bonds
B
Suppose you encounter a chemical formula with H as the cation. What do you know about this compound immediately? a. It is a polyatomic ionic compound. b. it is an acid. c. It is a base. d. It has a +1 charge.
B
The electron configuration of nitrogen is 1s²2s²2p³. How many more electrons does nitrogen need to satisfy the octet rule? a. 1 b. 3 c. 5 d. 8
B
VSEPR theory is a model for predicting a. the strength of metallic bonds b. the shape of molecules c. lattice energy values d. ionization energy
B
What is the formula for sulfur dichloride? a. SCl b. SCl₂ c. S₂Cl d. S₂Cl₂
B
What is the formula for zinc fluoride? a. ZnF b. ZnF₂ c. Zn₂F d. Zn₂F₃
B
What is the name given to the electrons in the highest occupied energy level of an atom? a. orbital electrons b. valence electrons c. anions d. cation
B
What type of ions have names ending in -ide? a. only cations b. only anions c. only metal ions d. only gaseous ions
B
Which of the following is NOT characteristic of most ionic compounds? a. They are solids. b. They have low melting points. c. When melted, they conduct an electric current. d. They are composed of metallic and nonmetallic elements.
B
Which of the following is not an example of a molecular formula? a. H₂O b. B c. NH₃ d. O₂
B
Which of the following is the correct name for N₂O₅? a. nitrous oxide b. dinitrogen pentoxide c. nitrogen dioxide d. nitrate oxide
B
Which of the following particles are free to drift in metals? a. protons b. electrons c. neutrons d. cations
B
Which set of chemical name and formula for the same compound is correct? a. ammonium sulfite, (NH₄)₂S b. iron(III) phosphate, FePO₄ c. lithium carbonate, LiCO₃ d. magnesium dichromate, MgCrO₄
B
Why do atoms share electrons in covalent bonds? a. to become ions and attract each other b. to attain a noble gas electron configuration c. to become more polar d. to increase their atomic numbers
B
of an atom for the shared electrons is called the atom's a. electron affinity b. electronegativity c. resonance d. hybridization
B
In a molecule of fluorine, the two shared electrons give each fluorine atom how many electron(s) in the outer energy level? a. 1 b. 2 c. 8 d. 32
C
In naming a binary molecular compound, the number of atoms of each element present in the molecule is indicated by __________ a. Roman numerals b. superscripts c. prefixes d. suffixes
C
Which of the following correctly provides the name of the element, the symbol for the ion, and the name of the ion? a. fluorine, F⁺, fluoride ion b. zinc, Zn²⁺, zincate ion c. copper, Cu⁺, cuprous ion d. sulfur, S²⁻ sulfurous ion
C
The ions in most ionic compounds are organized into a a. molecule b. Lewis structure c. polyatomic ion d. crystal
D
The reason the boiling point of water (H₂O) is higher than the boiling point of hydrogen sulfide (H₂S) is partially explained by a. London forces b. covalent bonding c. ionic bonding d. hydrogen bonding
D
What determines that an element is a metal? a. the magnitude of its charge b. the molecules that it forms c. when it is a Group A element d. its position in the periodic table
D
Which elements can form diatomic molecules joined by a single covalent bond? a. hydrogen only b. halogens only c. halogens and members of the oxygen group only d. hydrogen and the halogens only
D
Which of the following correctly provides the names and formulas o polyatomic ions? a. carbonate, HCO₃⁻; bicarbonate, CO₃²⁻ b. nitrite, NO⁻; nitrate NO₂⁻ c. sulfite, S²⁻, sulfate, S0₃⁻ d. chromate, CrO₄²⁻; dichromate, Cr₂O₇²⁻
D
Which of the following elements can form diatomic molecules held together by triple covalent bonds? a. carbon b. oxygen c. fluorine d. nitrogen
D