CHEM 1035 - SmartBook Chapter 9 Part I

When the elements Mg and Cl form an ionic bond, Mg loses __________ electron(s) from the 3s orbital to form the Mg2+ cation. Cl gains __________ electron(s) in the 3p orbital to form the Cl- anion. Since the total number of electrons lost always equals the total number of electrons gained, the compound formed will contain __________ Mg2+ ion(s) for every __________ Cl- ion(s). Fill in the blanks with the appropriate numbers.

2 1 1 2

The covalently bonded species shown has _____ bonding pair(s) of electrons and _____ lone pair(s). 2; 2 4; 0 3; 1 1; 3

3; 1

Which statement correctly describes the general characteristics of a covalent bond? Select all that apply. Electrons shared between the atoms are delocalized in an electron sea. A covalent bond involves the sharing of electrons between two atoms. The covalent bond involves the attraction between the nucleus of each atom and the electrons of the other. The covalent bond is typically observed when a metal bonds to a nonmetal.

A covalent bond involves the sharing of electrons between two atoms. The covalent bond involves the attraction between the nucleus of each atom and the electrons of the other.

Which of the following statements correctly describe ionic bonding? Select all that apply. An ionic bond is the electrostatic attraction between two oppositely charged ions. Ionic bonding involves the transfer of electrons from the metal to the nonmetal. Positive and negative ions combine in individual units of two or three ions each. Ionic bonding is typically observed when two nonmetals bond.

An ionic bond is the electrostatic attraction between two oppositely charged ions. Ionic bonding involves the transfer of electrons from the metal to the nonmetal.

Order the following covalent bonds in terms of increasing bond length based on general trends. Start with the shortest bond at the top of the list. C-N C=N C≡N

C≡N C=N C-N

Order the following covalent bonds in terms of increasing bond strength, based on general trends. Place the weakest bond at the top of the list. H-S H-F H-N H-O

H-S H-N H-O H-F

Consider the formation of an ionic bond between the elements potassium (K) and chlorine (Cl). Which of the following statements describe this process correctly? Select all that apply. K loses one electron from its 4s orbital to form a K+ cation. Both the K+ and Cl- ions have full outer shells containing 8 electrons. The total number of electrons lost equals the total number of electrons gained. The formation of this bond requires two K atoms for every one Cl atom. Cl gains two electrons to form the Cl- anion.

K loses one electron from its 4s orbital to form a K+ cation. Both the K+ and Cl- ions have full outer shells containing 8 electrons. The total number of electrons lost equals the total number of electrons gained.

Arrange the following ionic compounds in order of decreasing lattice energy (decreasing strength of the ionic bond) based on general periodic trends. Start by placing the compound with the highest lattice energy at the top of the list. Na2O MgO KBr

MgO Na2O KBr

Which of the following statements best explains why most covalent substances do not conduct electricity, even when melted or in solution? No molecules are present to carry the charge. No ions or free electrons are present to carry the charge. No nonelectrolytes are present to carry the charge.

No ions or free electrons are present to carry the charge.

Which of the following options describe how to draw the Lewis electron-dot symbol for a given element? Select all that apply. Dots are placed initially in pairs on the sides of the element symbol to represent the valence electrons. Dots are placed clockwise, starting at the top of the symbol. One dot is placed on each side of the element symbol before pairing any dots. The Lewis symbol includes only the valence electrons for the element. The A-group number of the element gives the number of valence electrons.

One dot is placed on each side of the element symbol before pairing any dots. The Lewis symbol includes only the valence electrons for the element. The A-group number of the element gives the number of valence electrons.

Which statement below correctly describes an ionic compound? The compound is a hard solid that can be shaped with a hammer, is not soluble in water, and conducts electricity in the solid and liquid states. The compound is a solid at room temperature, does not conduct electricity, and dissolves in water to give a solution that conducts electricity. The compound is a soft solid that dissolves readily in water. Neither the solid nor the solution conducts electricity.

The compound is a solid at room temperature, does not conduct electricity, and dissolves in water to give a solution that conducts electricity.

Which of the following factors affect the magnitude of the lattice energy for an ionic compound? Select all that apply. The size of the ions The charges of the ions The number of valence electrons in the ions The total number of positive and negative ions present The arrangement of the ions in the crystal

The size of the ions The charges of the ions The arrangement of the ions in the crystal

The formation of an ionic compound involves the transfer of electrons. The removal of one or more electrons from a metal is a process that _____ energy, whereas the addition of one or more electrons to a nonmetal _____ energy. absorbs; releases releases; absorbs

absorbs; releases

The __________ rule states that when atoms bond they may lose, gain, or __________ electrons in order to attain an outer level containing eight electrons.

octet share

The bond __________ is given by the number of electron pairs shared between two bonded atoms. For a double bond such as C=O, this number is __________ because there is/are __________ electron pair(s) shared between the two atoms.

order 2 2

An ionic solid does not conduct electricity in the solid state because the ions are held together by __________ attractive forces and cannot move from their positions in the crystal structure. If the solid melts or dissolves in water, the ions are free to move and carry a(n) __________ current.

strong electric

Ionic compounds are hard and brittle because ______. weak intermolecular forces easily crack and detach shared electrons between atoms hold them in specific positions delocalized valence electrons hold cations in a lattice pattern strong attractive forces hold ions in specific positions

strong attractive forces hold ions in specific positions

Melting an ionic solid involves freeing the ions from their positions in the ionic crystal and separating them. Since the ions are held together by _____ electrostatic attractions, the amount of energy required is _____ and ionic solids therefore have relatively _____ melting points. weak; large; high strong; large; low weak; small; low strong; large; high

strong; large; high

Which of the following are characteristic properties of ionic compounds? Select all that apply. Hard but flexible Nonconductors in aqueous solution High melting points Nonconductors in the solid state

High melting points Nonconductors in the solid state

Which of the following statements correctly describe trends in lattice energy? Select all that apply. NaCl should have a higher lattice energy than Na2O. The lattice energy of an ionic compound tends to decrease as ionic size increases. The lattice energy of an ionic compound decreases as the charges on the ions increase. NaCl is expected to have a higher lattice energy than NaBr.

The lattice energy of an ionic compound tends to decrease as ionic size increases. NaCl is expected to have a higher lattice energy than NaBr.

A pair of electrons shared between two atoms in a covalent bond is called a shared or __________ electron pair, whereas an outer-level electron pair that is not involved in bonding is called an unshared or __________ pair.

bonding lone

It is possible for two covalently bonded atoms to share more than one electron pair. For example, in a double bond there are _____ shared electron pairs, making a total of _____ shared electrons, and the bond order is _____. 2; 4; 2 1; 2; 2 2; 2; 2

2; 4; 2

Which of the following statements correctly describe bond energy? Select all that apply. Bond energy is the energy required to break a covalent bond. Bond energy is the energy released when two oppositely charged ions attract. Bond energy is equal in magnitude to the energy released when a bond is formed. Bond energies are always negative values. Bond energy is a measure of bond strength.

Bond energy is the energy required to break a covalent bond. Bond energy is equal in magnitude to the energy released when a bond is formed. Bond energy is a measure of bond strength.

Arrange the following ionic compounds in order of increasing lattice energy (increasing strength of the ionic bond) based on general trends in lattice energy. Start with the compound that has the lowest lattice energy at the top of the list. Instructions MgCl2 Li2O CaBr2

CaBr2 MgCl2 Li2O

The formation of an ionic bond involves a number of different processes. If we consider the separate electron transfer processes involved in the formation of sodium chloride, which individual steps would require an input of energy? The overall process is represented by the equation shown below. Select all that apply. 2Na (s) + Cl2 (g) → 2NaCl (s) Conversion of Na (s) → Na (g) Removal of an electron from Na The addition of an electron to each Cl atom Attraction of Na+ and Cl- to form NaCl Dissociation of Cl2 to form 2Cl

Conversion of Na (s) → Na (g) Removal of an electron from Na Dissociation of Cl2 to form 2Cl

Which statement best explains the factors that affect ionic bond strength in terms of electrostatic energy? Electrostatic energy increases as the magnitude of the oppositely charged ions increases and their separation increases. Electrostatic energy decreases as the magnitude of the oppositely charged ions increases and their separation increases. Electrostatic energy increases as the magnitude of the oppositely charged ions increases and their separation decreases. Electrostatic energy decreases as the magnitude of the oppositely charged ions increases and their separation decreases.

Electrostatic energy increases as the magnitude of the oppositely charged ions increases and their separation decreases.

Why does an ionic solid not conduct electricity in the solid state but is a good conductor when melted or dissolved in water? Select all that apply. An ionic solid contains a metal, and metals conduct electricity. In the liquid or dissolved state, the ions can release electrons that cause a current to flow. In the solid state, the ions are held in specific positions and are not free to move. In the liquid or dissolved state, the ions are free to move and can carry an electric current.

In the solid state, the ions are held in specific positions and are not free to move. In the liquid or dissolved state, the ions are free to move and can carry an electric current.

Which of the following statements correctly describe ionic bonding? Select all that apply. Ionic bonding involves the transfer of electrons from the metal to the nonmetal. An ionic bond is the electrostatic attraction between two oppositely charged ions. Positive and negative ions combine in individual units of two or three ions each. Ionic bonding is typically observed when two nonmetals bond.

Ionic bonding involves the transfer of electrons from the metal to the nonmetal. An ionic bond is the electrostatic attraction between two oppositely charged ions.

Which of the following options correctly relate the physical properties of ionic solids to the nature of the ionic bond? Select all that apply. Ionic solids are brittle because any impact causes ions of the same charge to be pushed together. Repulsion causes the solid to crack. An ionic solid can change shape fairly easily because each positive ion is attracted equally to each negative ion that surrounds it. Ionic solids are brittle because the ions in the crystal are too far apart to attract each other strongly. Ionic solids are soft because the ionic bond is weak. Ionic solids are fairly rigid due to the arrangement of the ions in a regular crystal lattice.

Ionic solids are brittle because any impact causes ions of the same charge to be pushed together. Ionic solids are fairly rigid due to the arrangement of the ions in a regular crystal lattice.

Which of the following options correctly describe lattice energy? Select all that apply. Lattice energy is the energy required to force gaseous ions together to form 1 mol of an ionic solid. Lattice energy is the energy required to separate 1 mol of an ionic solid into gaseous ions. Lattice energy provides a measure of the strength of an ionic bond. Lattice energy decreases as the attraction between the ions increases. Lattice energy is the energy required to arrange the ions of an ionic solid in a regular lattice.

Lattice energy is the energy required to separate 1 mol of an ionic solid into gaseous ions. Lattice energy provides a measure of the strength of an ionic bond.

Match each type of chemical bond to the correct description. Covalent bond → _____ Ionic bond → _____ Metallic bond → _____ Sharing of electrons between two atoms due to the attraction between the nucleus of each atom and the electrons of the other Sharing of all valence electrons as an "electron sea" by all the atoms of the substance The attraction between two oppositely charged particles formed by the transfer of electrons between two atoms

Sharing of electrons between two atoms due to the attraction between the nucleus of each atom and the electrons of the other The attraction between two oppositely charged particles formed by the transfer of electrons between two atoms Sharing of all valence electrons as an "electron sea" by all the atoms of the substance

Which of the following options correctly describe the relationships between bond order, bond length, and bond energy? Select all that apply. The longer the bond, the higher the bond energy. The shorter the bond, the greater the bond strength. The higher the bond order, the weaker the bond. For a given pair of atoms, a higher bond order means a shorter bond.

The shorter the bond, the greater the bond strength. For a given pair of atoms, a higher bond order means a shorter bond.

Select the type of chemical bond that most commonly forms between each combination of elements as indicated. Metallic bond → _____ Covalent bond → _____ Ionic bond → _____ Two or more metal atoms Metal to nonmetal Nonmetal to nonmetal

Two or more metal atoms Nonmetal to nonmetal Metal to nonmetal

The energy required to overcome the attraction between two bonded nuclei and their shared electrons is called _____ energy. This quantity is a measure of bond strength since the stronger the bond, the _____ the amount of energy required to break it. lattice; greater bond; smaller lattice; smaller bond; greater

bond; greater

The bond formed between two nonmetals, which are usually very similar in their tendency to lose or gain electrons, is the _____ bond. This bond involves the _____ of one or more electron pairs between the two atoms. covalent; transfer ionic; transfer ionic; sharing covalent; sharing

covalent; sharing

The bond length of a covalent bond is the distance between the nuclei of two bonded atoms. The larger the atoms, the _____ this distance will be. Bond length therefore _____ as atomic size decreases. smaller; increases smaller; decreases greater; increases greater; decreases

greater; decreases

Bond order, bond length, and bond energy are closely related. The shorter a bond, the _____ its bond strength. A shorter bond will therefore have a higher bond energy than a longer bond. Bond order also plays a role. For a given pair of atoms, the higher the bond order, the shorter and _____ the bond will be. greater; weaker lower; weaker greater; stronger lower; stronger

greater; stronger

The lattice energy of an ionic solid is a measure of the attraction between the oppositely charged ions. As ionic charge increases, the attraction between the ions _____ and so does the lattice energy. As the size of the ions increases, the attraction between the ions _____ and so does lattice energy. Lattice energy therefore _____ down a group of the periodic table and _____ across a period. decreases; decreases; increases; increases increases; decreases; increases; decreases decreases; increases; increases; decreases increases; decreases; decreases; increases

increases; decreases; decreases; increases

For a series of similar covalent bonds, bond length _____ as atomic size increases. A C-O bond would therefore be _____ than a Si-O bond. Multiple choice question. decreases; longer increases; longer decreases; shorter increases; shorter

increases; shorter

Ionic compounds typically have high melting and boiling point temperatures because of the strength of their _____. intermolecular bonds polar bonds covalent bonds ionic bonds

ionic bonds

The bond typically observed when a metal bonds to a nonmetal is the _____ bond. The metal atom _____ one or more valence electrons while the nonmetal _____ electrons. covalent; gains; loses ionic; loses; gains ionic; gains; loses covalent; loses; gains

ionic; loses; gains

Most covalent substances do not conduct electricity, even when melted or in solution. An electric current is carried by the movement of either electrons or __________. In covalent substances the electrons are localized either as __________ pairs or as lone pairs, and no ions are present. Since there are no charged particles free to move, covalent substances are poor electrical conductors.

ions bonded

The amount of energy required to separate 1 mole of ions in a crystalline solid into separate gaseous ions is called _____ energy. This energy provides a measure of the strength of a(n) _____ bond, since the stronger the bond, the _____ the amount of energy required to break it. lattice; ionic; greater electrostatic; ionic; greater dissociation; covalent; greater lattice; ionic; smaller

lattice; ionic; greater

Atoms bond in order to attain a full __________ level or shell of electrons. Elements in Period 2 strive for a total of __________ such electrons while Period 1 elements such as hydrogen strive for a total of __________.

outer 8 2

To draw the Lewis electron-dot symbol for a main-group element, first determine the number of __________ electrons by noting the __________ number of the element. Place one __________ for each electron on each of the four sides of the element symbol, pairing them up once each site has an electron.

valence A group dot