chem

In general, intramolecular forces determine the ________ properties of a substance and intermolecular forces determine its ________ properties.

chemical, physical

Hyrogen bonding

occurs when hydrogen is covalently bonded to H, N, F

An unknown metal crystallizes in a primitive cubic unit cell. The length of the unit cell edge is 2.85 Å. The radius of the unknown atom is ________ Å. A) 1.01 B) 1.85 C) 1.43 D) 5.70 E) Insufficient data is given.

C

Crystalline solids ________. A) exist only at high temperatures B) have their particles arranged randomly C) have ordered structures D) exist only at very low temperatures E) are usually very soft

C

Identify the characteristics of a liquid. A) definite shape and volume B) indefinite shape and volume C) indefinite shape, but definite volume D) none of the above E) all of the above

C

If all of the following are in solid phase, which is considered a non-bonding atomic solid? 'A) Li B) I2 C) Ne D) Fe E) Ca

C

In liquids, the attractive intermolecular forces are ________. A) strong enough to keep the molecules confined to vibrating about their fixed lattice points B) not strong enough to keep molecules from moving past each other C) strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other D) very weak compared with kinetic energies of the molecules E) strong enough to hold molecules relatively close together

C

The concentration of CO2 in a soft drink bottled with a partial pressure of CO2 of 4.0 atm over the liquid at 25 °C is 1.2 × 10-1 M. The Henryʹs law constant for CO2 at this temperature is ________. A) 5.6 × 10-3 mol/L-atm B) 2.3 × 10-2 mol/L-atm C) 3.0 × 10-2 mol/L-atm D) 4.5 × 10-3 mol/L-atm E) More information is needed to solve the problem.

C

The heat of fusion of water is 6.01 kJ/mol. The heat capacity of water is 75.3 kJ. The conversion of 50.0 mol of ice at 0.00 C to water at 0.00 requires ____ kj of heat. A) 75.3 B) 6.01 C) 16.7 D) 17.2

C

The solubility of nitrogen gas at 25 °C and 1 atm is 6.8 × 10-4 mol/L. If the partial pressure of nitrogen gas in air is 0.76 atm, what is the concentration (molarity) of dissolved nitrogen? A) 6.8 × 10-4 M B) 3.8 × 10-4 M C) 5.2 × 10-4 M D) 1.1 × 10-5 M E) 4.9 × 10-4 M

C

What is the strongest type of intermolecular force present in NH2CH3? A) dipole-dipole B) dispersion C) hydrogen bonding D) ion-dipole E) None of the above

C

What portion of the volume of each atom or ion on the face of a unit cell is actually within the unit cell? A) 1/4 B) 3/4 C) 1/2 D) all of it E) none of it

C

Which of the following compounds will be most soluble in pentane (C5H12)? A) pentanol (CH3CH2CH2CH2CH2OH) B) acetic acid (CH3CO2H) C) benzene (C6H6) D) ethyl methyl ketone (CH3CH2COCH3) E) None of these compounds should be soluble in pentane

C

Which of the following is considered an ionic solid? A) SeBr2 B) XeF4 C) (NH4)2CO3 D) CCl4 E) None of these is an ionic solid.

C

Which of the following statements is true? A) The solubility of a gas in water decreases with increasing pressure. B) The solubility of a gas in water increases with decreasing pressure. C) The solubility of a gas in water increases with increasing pressure. D) The solubility of a gas in water decreases with decreasing pressure. E) None of the above statements are true.

C

(a) Identify the intermolecular attractions present in the following substances and (b) select the substance with the highest boiling point: CH3CH3, CH3OH, and CH3CH2OH.

CH3CH3 is non polar in nature So, It will have London dispersion forces CH3OH is polar in nature So, It will have London dispersion forces and hydrogen bonding CH3CH2OH is polar in nature So, It will have London dispersion forces and hydrogen bonding London dispersion forces will be stronger here as compared to CH3OH. So, boiling point is maximum here Answer: CH3CH2OH

Based on molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point? Substance, Molecular Mass (amu), Dipole Moment Propane, CH3CH2CH3 44 0.1 Dimethylether, CH3OCH3 46 1.3 Methylchloride, CH3Cl 50 1.9 Acetaldehyde, CH3CHO 44 2.7 Acetonitrile, CH3CN 41 3.9

CH3CN

List the substances Ar, Cl2, CH4, and CH3COOH in order of increasing strength of intermolecular attractions. (a) CH4 < Ar < CH3COOH < Cl2 (b) Cl2 < CH3COOH < Ar < CH4 (c) CH4 < Ar < Cl2 < CH3COOH (d) CH3COOH < Cl2 < Ar < CH4 (e) Ar < Cl2 < CH4 < CH3COOH

CH4​<Ar<Cl2​<CH3​COOH The methane molecule has one carbon atom and four hydrogen atoms. The bond formed between carbon and hydrogen atom is nonpolar, as the electronegativity difference between carbon and a hydrogen atom is very less.

A solution containing less than the equilibrium amount of solvent is called ________. A) a supersaturated solution B) a solute C) a solvent D) an unsaturated solution E) a saturated solution.

D

All of the following are a type of solid except ________. A) molecular B) ionic C) metallic D) supercritical E) covalent network

D

All of the following are alloys except ________. A) sterling silver B) 14-karat gold C) yellow brass D) ceramic E) dental amalgam

D

Identify the gas that is dissolved in carbonated sodas. A) carbon monoxide B) nitrogen C) hydrogen D) carbon dioxide E) oxygen

D

What types of intermolecular forces exist between NH3 and H2O? A) dispersion forces and hydrogen bonds B) dispersion forces, hydrogen bonds, and ion-dipole forces C) dispersion forces and ion-dipole forces D) dispersion forces, dipole-dipole forces, and hydrogen bonds E) dispersion forces

D

Which of the following substances is most likely to be a liquid at room temperature? (a) formaldehyde, H2CO (b) fluoromethane, CH3F (c) hydrogen cyanide, HCN (d) hydrogen peroxide, H2O2 (e) hydrogen sulfide, H2S

D

If the electronic structure of a solid substance consists of a valence band that is completely filled with electrons and there is a large energy gap to the next set of orbitals, then this substance will be a(n) ________. A) alloy B) nonmetal C) conductor D) semiconductor E) insulator

E

The dissolution of water in octane (C8H18) is principally prevented by ________. A) London dispersion forces between octane molecules B) repulsion between like-charged water and octane molecules C) dipole-dipole attraction between octane molecules D) ion-dipole attraction between water and octane molecules E) hydrogen bonding between water molecules

E

The process of ________ can produce an n-type semiconductor, which can greatly increase intrinsic conductivity. A) fusing B) infusing C) melting D) mixing E) doping

E

Which of the following can be used as an elemental semiconductor? A) H B) Ne C) Au D) Li E) Ge

E

________ is the energy required to expand the surface area of a liquid by a unit amount of area. A) Capillary action B) Viscosity C) Volatility D) Meniscus E) Surface tension

E

Of the following substances, ___ has the highest boiling point. A) H2 B) Cl2 C) N2 D) O2 E) Br2

E) Br2 -- has the highest boiling point because its the largest

List the substances BaCl2, H2, CO, HF, and Ne in order of increasing boiling point

H2 < Ne < CO < HF < BaCl2 The attractive forces are stronger for ionic substances than for molecular ones, so BaCl2 should have the highest boiling point. The intermolecular forces of the remaining substances depend on molecular weight, polarity, and hydrogen bonding. The molecular weights are H2, 2 amu; CO, 28 amu; HF, 20 amu; and Ne, 20 amu. The molecular weights of CO, HF, and Ne are similar. Because HF can hydrogen-bond, it should have the highest boiling point of the three.

Choose the pair of substances that are most likely to form a homogeneous solution. A) C6H14 and C10H20 B) N2O4 and NH4Cl C) C6H14 and H2O D) LiBr and C5H12 E) None of the pairs above will form a homogeneous solution

A

Calculate the enthalpy change upon converting 1.00 mol of ice at -25 °C to steam at 125 °C under a constant pressure of 1 atm. The specific heats of ice, liquid water, and steam are 2.03, 4.18, and 1.84 J/g-K, respectively. For H2O, ΔHfus = 6.01 kJ/mol and ΔHvap = 40.67 kJ/mol

AB= H= (1.00 mol)(18.0 g/mol)(2.03 J/g-k)(25K) = 914 J =.91 kJ BC= H= (1.00 mol)(6.01 kJ/mol)= 6.01kJ CD= H= (1.00 mol)(18.0 g/mol)(4.18 J/g-k)(100k)= 7520 J= 7.52 kJ DE= H=

Identify the phase in which the water molecules are closest together. A) dry ice B) liquid C) gas D) solid

B

Which one of the following vitamins is water soluble? A) A B) B C) K D) D E) E

B

Ethanol melts at -114 C and boils at 78 C at constant pressure of 1 atm. What state of matter must a sample of ethanol be at 0 C and 1 atm? A) solid and liquid in equilibrium B) liquid C) gas D) liquid and gas in equilibrium E) solid

B)

With what compound will NH3 experience only dispersion intermolecular forces? A) LiF B) BF3 C) CH3I D) HCN E) CH3OH

B) BF3 = is nonpolar

Which is expected to have the largest dispersion forces? A) C3H8 B) F2 C) Be Cl2 D) C12H26

D

T/F An insulator does not conduct electricity.

T

London Dispersion Forces tend to ________ in strength with increasing molecular weight.

increase

The conversion of a solid to a liquid is called ________.

melting

A volatile liquid is one that ________. A) is highly cohesive B) is highly hydrogen-bonded C) is highly flammable D) is highly viscous E) readily evaporates

E

Give the intermolecular force that is responsible for the solubility of ethanol in water. A) dispersion forces B) ion-dipole forces C) dipole-dipole forces D) ionic forces E) hydrogen bonding

E

A metallic material that is composed of two or more elements is called a(n) ________. A) alloy B) nonmetal C) mineral D) homogeneous mixture E) pure metal

A

A solid has a very high melting point, great hardness, and poor electrical conduction. This is a(n) ________ solid. A) covalent network B) ionic C) molecular D) metallic and covalent network E) metallic

A

Based on the following information, which compound has the strongest intermolecular forces? Substance ΔHvap (kJ/mol) Argon (Ar) 6.3 Benzene (C6H6) 31.0 Ethanol (C2H5OH) 39.3 Water (H2O) 40.8 Methane (CH4) 9.2 A) Water B) Methane C) Benzene D) Argon E) Ethanol

A

NaCl crystallizes in a cubic unit cell with Cl- ions on each corner and each face. How many Na+ and Cl- ions are in each unit cell of NaCl? A) 4 Na+ ions and 4 Cl- ions B) 1 Na+ ion and 1 Cl- ion C) 8 Na+ ions and 8 Cl- ions D) 2 Na+ ions and 2 Cl- ions

A

Place the following substances in order of increasing boiling point. Ne Cl2 O2 A) Ne < O2 < Cl2 B) O2 < Cl2 < Ne C) Cl2 < O2 < Ne D) Cl2 < Ne < O2 E) Ne < Cl2 < O2

A

The phrase ʺlike dissolves likeʺ refers to the fact that ________. A) polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes B) polar solvents dissolve nonpolar solutes and vice versa C) gases can only dissolve other gases D) condensed phases can only dissolve other condensed phases E) solvents can only dissolve solutes of similar molar mass

A

What type of intermolecular force causes the dissolution of NaCl in water? A) ion-dipole force B) hydrogen bonding C) dipole-dipole forces D) dispersion forces E) None of the above

A

Which molecule has hydrogen bonding as the predominant intermolecular force? A) CH3OH B) C6H6 C) CO2 D) CH4 E) C4H10

A

Which of the following is considered a molecular solid? A) I2 B) NH4NO3 C) Xe D) Cu E) None of these is a molecular solid.

A

Which of the following is considered an atomic solid? A) Nb B) N2 C) CsCl D) Br2 E) None of these is an atomic solid.

A

Which of the following statements is true? A) Vapor pressure increases with temperature. B) Dispersion forces are generally stronger than dipole-dipole forces. C) Hydrogen bonds are stronger than covalent bonds. D) Intermolecular forces hold the atoms in molecules together. E) None of the above are true.

A

The enthalpy change for converting 1 mol of ice at -25 C to water at 50 C is_______ kJ. A) 10.71 B) 6.27 C) 4709 D) 12.28 E) 8.83

A)

Which one of the following should have the lowest boiling point? A)CH4 B) Cl2S C) C2H5COOH D) LiCl E) PCl3

A) CH4

Of the following substances, ___ has the highest boiling point. A) H2O B) BF3 C) Cl2 D) SiH4 E) Ar

A) H20 --- only one w dipole forces

1) As a gaseous element condenses, the atoms become ___ and they have ___ attraction for ____ one another. A) less separated, more B) smaller, lesser C) more separated, more D) more separated, less E) less separated, less

A) less separated, more

All of the following can form a solid with a lattice structure similar to that of sodium chloride except ________. A) LiCl B) CuBr2 C) MgO D) KI E) NaF

B

Choose the molecule or compound that exhibits dispersion forces as its strongest intermolecular force. A) HF B) Cl2 C) NaCl D) CO E) All of these have intermolecular forces stronger than dispersion

B

How many H- ions are around each Na+ ion in NaH, which has a cubic unit cell with H- ions on each corner and each face? A) 1 B) 6 C) 8 D) 4

B

How much heat is released when 105 g of steam at 100.0°C is cooled to ice at -15.0°C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol ∙ °C), and the molar heat capacity of ice is 36.4 J/(mol ∙ °C). A) 347 kJ B) 319 kJ C) 54.8 kJ D) 273 kJ

B

The enthalpy change for converting 10.0 mol of ice at -50 C to water at 50 C is ____ kJ. A) 3138 B)6.47 C) 9.15 D) 17.2

B

Which of the following should have the largest Henryʹs law constant (kH) in water? A) Xe B) CO C) CO2 D) CH3CH3 E) Ar

B

Which species has London dispersion forces as the only intermolecular force? A) CH3OH B) CH3CH3 C) CH3F D) HI E) KBr

B

Of the following, ______ is the most volatile A) C2Cl6 B) C2H6 C) C2Br6 D) C2I6 E) C2F6

B) C2H6

Which molecule is the least volatile? A) CH3F B) CH3I C)CH4 D) CH3Cl E) CH3Br

B) CH3I

What is the predominant intramolecular force in NaNO3? A) dipole-dipole attraction B) ionic bonding C) ion-dipole attraction D) London-dispersion forces E) hydrogen bonding

B) Ionic Bonding

Consider the following statements about crystalline solids: (i) Molecules or atoms in molecular solids are held together via ionic bonds. (ii) Metallic solids have atoms in the points of the crystal lattice. (iii) Ionic solids have formula units in the point of the crystal lattice. (iv) Molecules in covalent-network solids are connected via a network of covalent bonds Which of the statements is true? A) (i) B) (ii) C) (iii) D) (iv) E) none

B) ii

Which one of the following exhibits dipole-dipole attraction between molecules? A) CS2 B) BI3 C) HCl D) F2 E)CF4

C) HCl

1) Molecular solids consist of atoms or molecules held together by ________. A) Metallic bonds only B) hydrogen bonds only C) dipole-dipole forces only D) London dispersion forces and hydrogen bonds only E) dipole-dipole forces, London dispersion forces, and/or hydrogen bonds

E

Of the following substances, only ___ has London dispersion forces as its only intermolecular force. A) H20 B)CH3OH C)HI D)CCl4 E)SnF3

D) CCl4

What is the predominant intermolecular force in HCN? A) Ionic bonding B)Hydrogen bonding C)London Dispersion forces D)dipole-dipole attraction E) Ion dipole

D) dipole dipole

In which of these substances is significant hydrogen bonding possible: methylene chloride (CH2Cl2), phosphine (PH3), chloramine (NH2Cl), acetone (CH3COCH3)?

NH2Cl hydrogen is covalently bonded to N

T/F? Many metals are ductile, which means that they can be drawn into thin wires.

T

T/F? The boiling points of normal hydrocarbons are higher than those of branched hydrocarbons of similar molecular weight because the London-dispersion forces between normal hydrocarbons are greater than those between branched hydrocarbons.

T

T/F? Under ordinary conditions, a substance will sublime rather than melt if its triple point occurs at a pressure above atmospheric pressure

T

T/TF? Heats of vaporization are greater than heats of fusion

T

A solution is formed at room temperature by vigorously dissolving enough of the solid solute so that some solid remains at the bottom of the solution. Which statement below is true? A) The solution would be considered unsaturated if it were cooled a bit to increase the solubility of the solid. B) The solution is considered supersaturated. C) The solution is considered saturated. D) The solution is considered unsaturated. E) None of the above are true

c