Chem 115 Final

When a nonmetal bonds with a nonmetal

A) a molecular compound forms.

B) electrons are shared.

C) a covalent bond is involved.

D) all of the above are true

E) none of the above

D

The Lewis structure for carbon monoxide is : C ≡O : This structures shows

A) 2 lone pairs and 1 bonding pair.

B) 4 lone pairs and 1 bonding pair.

C) 4 lone pairs and 3 bonding pairs.

D) 2 lone pairs and 3 bonding pairs.

E) none of the above

D

Lewis theory predicts that the formula of a compound formed between bromine and aluminum is:

A) AlBr3

B) Al2Br

C) AlBr2

D) AlBr

E) none of the above

A

The elements with the highest electronegativity values tend to be found in the:

A) lower left-side of the periodic table.

B) center of the periodic table.

C) lower right-side of the periodic table.

D) upper right-side of the periodic table.

E) upper left-side of the periodic table.

D

Which sequence below represents the proper order of increasing bond strength?

A) single < double < triple

B) single < triple < double

C) triple < double < single

D) double < single < triple

E) none of the abov

A

Which of the following compounds would have a linear molecular geometry?

1. N2

2. H2S

3. CO2

A) 1 and 2 only

B) 2 and 3 only

C) 1 and 3 only

D) 1,2 and 3

E) neither 1, 2,or 3

C

The correct Lewis structure for BF3 would have exactly:

A) 1 triple bond.

B) no double bonds.

C) 1 double bond.

D) 2 double bonds.

E) none of the above

B

What is the molecular geometry if you have 3 single bonds and 1 lone pair around the central

atom?

A) linear

B) trigonal pyramidal

C) tetrahedral

D) bent

E) not enough information

B

The central atom in the chlorite anion, ClO2

- is surrounded by

A) two bonding and two unshared pairs of electrons.

B) one bonding and three unshared pairs of electrons.

C) two bonding and one unshared pair of electrons.

D) two double bonds and no unshared pairs of electrons.

E) none of the above

A

What is the electron geometry if you have 2 electron groups around the center atom?

A) tetrahedral

B) trigonal planar

C) linear

D) trigonal bipyramidal

E) not enough information

C

Which of the following statements is TRUE for the covalent molecule HCl?

A) Hydrogen is more electronegative and the shared electron pair is likely to be found on the

hydrogen atom.

B) Hydrogen is more electronegative and the shared electron pair is likely to be found on the

chlorine atom.

C) Chlorine is more electronegative and the shared electron pair is likely to be found on the

chlorine atom.

D) Chlorine is more electronegative and the shared electron pair is likely to be found on the

hydrogen atom.

E) none of the above

C

What is the molecular geometry of carbon dioxide, CO2?

A) bent

B) trigonal pyramidal

C) linear

D) tetrahedral

E) not enough information

C

Which of the following statements about Lewis structures is FALSE?

A) An octet is when an atom has 8 valence electrons.

B) A duet is a stable electron configuration for helium.

C) A covalent bond occurs when electrons are shared.

D) An ionic bond occurs when electrons are transferred.

E) All of the above statements are true

C

What is the molecular geometry if you have 4 single bonds around the central atom?

A) linear

B) tetrahedral

C) trigonal pyramidal

D) bent

E) not enough information

E

Which compound listed below will dissolve in NH3?

A) CO2

B) H2S

C) O2

D) all of the compounds

E) none of the compounds

B

. The electronegativity value for Mg is 1.2 and the value for O is 3.5. Based on these values, what

type of bond is expected for a compound formed between Mg and O?

A) Polar covalent

B) Ionic

C) Pure covalent

D) not enough information

E) none of the above

B

The central atom in the chlorate anion, ClO3

- is surrounded by

A) two bonding and two unshared pairs of electrons.

B) two double bonds and no unshared pairs of electrons.

C) one bonding and three unshared pairs of electrons.

D) three bonding and one unshared pair of electrons.

E) none of the above.

B

The electronegativity value for N is 3.0 and that for O is 3.5. Based on these values, which of the

following statements is TRUE about the compound NO?

A) NO is a pure covalent compound.

B) NO is an ionic compound.

C) NO is a polar covalent compound.

D) There is not enough enough information to determine the nature of NO.

E) None of the above statements is true.

D

Which Lewis structure below correctly represents the compound formed between magnesium and

sulfur?

A) [:

..

S

··

:]⁻ Mg⁺2 [:

..

S

··

:]⁻

B) Mg⁺ [:

..

S

··

:]⁻2 Mg⁺

C) Mg⁺ [:

..

S

··

:]⁻

D) Mg⁺2 [:

..

S

··

:]⁻2

E) none of the above

D

. Which molecule listed below has a polar covalent bond?

A) H2O

B) NaCl

C) H2

D) all of the compounds

E) none of the compounds

A

Which of the following statements about the water molecule is TRUE?

A) A water molecule has two dipole moments and they cancel each other.

B) A water molecule is symmetrical and therefore is nonpolar.

C) The electronegativities of hydrogen and oxygen are equal and therefore a water molecule is

nonpolar.

D) A water molecule is asymmetric and therefore is polar.

E) none of the above

D

What is the electron geometry if you have 4 electron groups around the center atom?

A) trigonal planar

B) linear

C) tetrahedral

D) trigonal bipyramidal

E) not enough information

C

Which molecule listed below is a polar molecule?

A) NH3

B) HCN

C) H2O

D) all of the compounds

E) none of the compounds

D

. Which molecule listed below has a nonpolar covalent bond?

A) H2O

B) H2

C) NaCl

D) all of the compounds

E) none of the compounds

B

Which compound listed below will dissolve in water?

A) NH3

B) SiO2

C) CCl4

D) all of the compounds

E) none of the compounds

A

What is the molecular geometry if you have a double bond, a single bond and 1 lone pair around

the central atom?

A) linear

B) tetrahedral

C) trigonal pyramidal

D) bent

E) not enough information

D

How does soap work?

A) Soap works by breaking grease molecules into smaller molecules that dissolve in water.

B) Soap works by having a polar end and a nonpolar end which allows the water and oil to

interact indirectly.

C) Soap works by making water into a nonpolar liquid which grease can dissolve in.

D) Soap works by by having a polar end which attaches to the grease molecule and polarizes it

and turns the grease molecule into another soap molecule. This is a chain reaction.

E) none of the above

B

Which of the following statements are TRUE about the BF3 molecule?

A) BF3 has a trigonal planar molecular geometry.

B) BF3 is nonpolar.

C) BF3 violates the octet rule for the central atom.

D) All of the above statements are true.

E) None of the above are true.

D

The electron geometry and the molecular geometry of ammonia (NH3

) are, respectively,

A) tetrahedral, bent.

B) tetrahedral, trigonal pyramidal.

C) tetrahedral, tetrahedral.

D) trigonal planar, bent.

E) none of the above

B

. Lewis theory predicts that the formula for a compound between fluorine and calcium is:

A) Ca2F

B) CaF3

C) CaF2

D) CaF

E) none of the above

C

What is the molecular geometry of PH3?

A) bent

B) linear

C) trigonal pyramidal

D) tetrahedral

E) not enough information

C

. Which of the following has a tetrahedral electron geometry and a trigonal pyramidal molecular

geometry?

A) PF3

B) Br2O

C) GeH4

D) SO2

E) none of the above

A

Which intermolecular forces are found in CO2?

A) dispersion forces

B) dispersion forces and dipole-dipole forces

C) dipole-dipole forces

D) hydrogen bonding

E) none of the above

A

Intermolecular forces are responsible for:

A) the function of DNA.

B) the existence of liquids and solids.

C) the taste sensations.

D) the shape of protein molecules.

E) all of the above

E

. Substance A is a molecular compound that dissolves in gasoline but not in water. The molecules of

A are very likely:

A) nonpolar.

B) metallic.

C) nonmetallic.

D) polar.

E) none of the above

A

Which intermolecular force increases with increasing molar mass?

A) X-forces

B) dipole-dipole forces

C) dispersion forces

D) hydrogen bonding

E) none of the above

C

Which compound will have the highest boiling point?

A) CH3CH3

B) CH3CH2OH

C) CH4

D) CH3C(O)CH3

E) not enough information

B

Which state of matter has a low density and an indefinite volume?

A) solids

B) gases

C) liquids

D) both solids and liquids

E) none of the above

B

The measure of the resistance to the flow of a liquid is called:

A) condensation.

B) viscosity.

C) vapor pressure.

D) sublimation.

E) none of the above

B

Evaporation is:

A) the opposite process as condensation.

B) a cooling process for humans when they sweat.

C) an endothermic process.

D) increased by increasing temperature.

E) all of the above

E

Which statement about surface tension is FALSE?

A) Items with densities lower than water will sink due to surface tension.

B) Molecules on the surface of the liquid have fewer molecules to interact with.

C) Liquids tend to minimize their surface area.

D) Increased intermolecular forces increase surface tension.

E) All of the above statements are true.

A

What are the principal forces holding ice together?

A) electrostatic attraction

B) sea of electrons

C) intermolecular forces

D) dispersion forces only

E) none of the above

C

Which statement about boiling point is FALSE?

A) The boiling point of a compound is an absolute constant.

B) The boiling point is higher for compounds with a high viscosity.

C) The boiling point of a compound is higher for nonvolatile compounds.

D) The boiling point is higher for compounds with strong intermolecular forces.

E) All of the above statements are true

A

How many kJ of heat are needed to completely vaporize 23.4 g of H2O? The heat of vaporization

for water at the boiling point is 40.6 kJ/mole.

A) 52.8

B) 31.2

C) 23.4

D) 2.26

E) none of the above

A

Which substance would be expected to have the highest boiling point?

A) O2

B) N2

C) CO2

D) CO

E) not enough information

D

Compare a small pot of water that is boiling vigorously to a large pot of water that is boiling gently.

Which statement is TRUE?

A) The vapor pressure of the liquid is greater than the pressure above the pot in each case.

B) The small pot is boiling at higher temperature than the large pot.

C) The large pot is boiling at a higher temperature than the small pot.

D) Both pots are boiling at the same temperature.

E) none of the above

D

How many kJ of heat are needed to completely melt 17.3 g of H2O, given that the water is at its

melting point? The heat of fusion for water is 6.02 kJ/mole.

A) 0.961

B) 1.04

C) 6.26

D) 5.79

E) none of the above

A

How many joules of heat are needed to completely vaporize 24.40 grams of water at its boiling

point?

Given ΔHvap = 40.6 kJ/mol

A) 5.50 × 104

B) 3.00 × 104

C) 54.97

D) 29.98

E) none of the above

A

How many kilojoules of heat are needed to completely vaporize 42.8 grams of C4H10O at its

boiling point?

Given ΔHvap = 26.5kJ/mol

A) 16.3

B) 9.49

C) 74.12

D) 15.3

E) none of the above

D