Gen. Chem. 2 Final

A substance has a fairly high density, flows freely, and, on the molecular level, is made up of particles that are very close to one another. This substance is _____________. A. a solid or a liquid. It is not possible to say for certain based on the information given B. a gas C. a solid D. a liquid

D. a liquid

Identify the Brønsted-Lowry acid, the Brønsted-Lowry base, the conjugate acid, and the conjugate base in this reaction. The underlined species is the: C5H5N(aq) + H2O(l) --> C5H5NH+(aq) + OH-(aq) OH-(aq) A. Brønsted-Lowry acid B. Brønsted-Lowry base C. conjugate acid D. conjugate base

D. conjugate base

Indicate the kind of intermolecular forces that would occur between the toluene (below) and hexane, C6H14. A. hydrogen bonding B. dipole-dipole C. ion-dipole D. dispersion

D. dispersion

At -78 degree Celsius and 5.2 atm, carbon dioxide is in which phase? A. supercritical fluid B. gas C. liquid D. solid

D. solid

According to the Valence Shell Electron Pair Repulsion (VSEPR) theory, a molecule or ion that has four electron groups around the central atom will have wha basic electron geometry? A. trigonal bipyramidal B. You cannot determine the basic electron geometry of a molecule or ion without knowing whether the electron groups are lone pairs or bonding groups. C. square planar D. tetrahedral

D. tetrahedral

Which of the acids below will ionize completely in aqueous solution? Hydrochloric acid, HCl Hydrofluoric acid, HF Acetic acid, HC2H3O2 a. acetic acid (HC2H3O2) only b. both hydrochloric acid (HCl) and hydrofluoric acid (HF) c. hydrofluoric acid (HF) only d. hydrochloric acid (HCl) only

d. hydrochloric acid (HCl) only

For the following reaction: 2Mg + O2 --> 2MgO, rate = [Mg][O2]^2 What would happen to the rate if [O2] were doubled? The rate would: a. stay the same. b. double. c. triple. d. quadruple.

d. quadruple.

The reaction X -> products is second order in X and has a rate constant of 0.035 M-1s-1. If a reaction mixture is initially 0.40 M in X, what is the concentration of X after 100 seconds? The second order rate law is: 1/[A]t = kt + 1/[A]o a. 0.39 M b. 0.17 M c. 0.33 M d. 0.00 M

b. 0.17 M

Calculate the pH of a solution in which [OH-]= 7.1x10^-3 pH = 14 + log(OH-) a. 8.02 b. 11.85 c. 12.98 d. 4.32

b. 11.85

What is the pH of a buffer that is 0.6 M HF and 0.2 M NaF? The Ka of HF is 6.8×10-4. pH = pKa + log([base]/[acid]) a. 3.50 b. 2.69 c. 3.65 d. 3.17

b. 2.69

A 40.00 mL sample of 0.10 M weak acid with Ka of 1.8×10-5 is titrated with a 0.10 M strong base. (Say NaOH) What is the pH after 20.00 mL of base has been added? a. 9.26 b. 7.00 c. 1.8×10-5 d. 4.74

b. 7.00

Which of the pairs below would be the best choice for a pH 5 buffer? HF/NaF, K a (HF) = 3.5 × 10-4 HC2H3O2/KC2H3O2, K a (HC2H3O2) = 1.8 × 10-5 NH3/NH4Cl, K b (NH3) = 1.8 × 10-5 a. NH3/NH4Cl is best. b. HC2H3O2/KC2H3O2 is best. c. HF/NaF is best. d. Both NH3/NH4Cl and HC2H3O2/KC2H3O2 would be equally good for a pH 5 buffer.

b. HC2H3O2/KC2H3O2 is best.

The pH of a 0.1 M solution of acetic acid, HC2H3O2, (Ka = 1.8 × 10-5) is 2.9. Based on this observation, which statement below best describes the pH of a 0.1 M solution of lactic acid, HC3H5O3, (Ka = 1.4 × 10-4)? a. Since lactic acid has a larger acid dissociation constant than acetic acid, a 0.1 M solution of lactic acid will have a larger pH value than a 0.1 Macetic acid solution. b. The pH of a 0.1 M acetic acid solution will be equal to the pH of a 0.1 M lactic acid solution since both are weak acids. c. Since lactic acid has a larger acid dissociation constant than acetic acid, a 0.1 M solution of lactic acid will have a smaller pH value than a 0.1 M acetic acid solution. d. Since lactic acid has a smaller acid dissociation constant than acetic acid, a 0.1 M solution of lactic acid will have a larger pH value than a 0.1 M acetic acid solution.

c.

Find [OH-] of a 0.33 M methylamine (CH3NH2) solution. (Methylamine has a Kb value of 4.4×10-4.) Express the concentration in moles per liter to two significant figures. a. 1.2×10-10 M b. 5.6×10-2 M c. 1.2×10-2 M d. 5.6×10-5 M

c. 1.2×10-2 M

A 50.0-mL sample of 0.200 M sodium hydroxide is titrated with 0.200 M nitric acid. Calculate the pH in the titration after you add a total of 60.0 mL of 0.200 M HNO3. Express the pH of the solution to two decimal places. pH=-log[H3O+]=-log0.0120 mol H3O+-0.0100 mol H3O+0.050 L+0.060 L=-log0.0020 mol H3O+0.110 L a. 9.26 b. 7.00 c. 1.74 d. 4.74

c. 1.74

Which statement is true regarding the function of a catalyst in a chemical reaction? a. A catalyst decreases the rate of a reaction b. A catalyst does not provide an alternate mechanism for the reaction. c. A catalyst is consumed by the reaction. d. All of the above are not true. mechanism for the reaction.

c. A catalyst is consumed by the reaction.

Which of the following statements about catalysis is/are true? 1) Catalysts are substances that change the rate of a chemical reaction, either speeding it up or slowing it down. 2) Because many biologically important reactions are very slow, living organisms rely on a class of catalysts called enzymes to increase the rate of biochemical reactions. 3) In heterogeneous catalysis, the catalyst and the substrate are always in different phases. a. Only statement 3 is true. b. All three statements are true. c. Both statements 2 and 3 are true. d. Both statements 1 and 2 are true.

c. Both statements 2 and 3 are true.

Identify the Brønsted-Lowry acid, the Brønsted-Lowry base, the conjugate acid, and the conjugate base in this reaction. The underlined species is the: C5H5N(aq) + H2O(l) --> C5H5NH+(aq) + OH-(aq) C5H5NH+(aq) a. Brønsted-Lowry acid b. Brønsted-Lowry base c. conjugate acid d. conjugate base

c. conjugate acid

When comparing the activation energy between different exothermic reactions, as the activation energy decreases at a given temperature, the reaction rate increases because the _______. a. reaction is no longer exothermic b. reaction changes and there are different products c. number of successful effective collisions is higher d. number of successful effective collisions is lower

c. number of successful effective collisions is higher

The balanced chemical equation for the synthesis of ammonia, the Haber process, is shown below. If the nitrogen gas is disappearing at a rate of 0.2 M /s, what is the rate at which ammonia is appearing at the same point in time in this reaction? N2(g) + 3 H2(g) ->2 NH3(g) a. 0.1M/s b. 0.08M/s c. 0.2 M/s d. 0.4M/s

d. 0.4M/s

Calculate the pH of a solution in which [H3O+] = 9.5x10^-9 pH = -log[H3O+] a. 5.98 b. 10.21 c. 7.00 d. 8.02

d. 8.02

Classify the following as covalent, ionic, metallic, or molecular: diamond A. covalent B. metallic C. molecular D. ionic

A. covalent

Classify the process as an endothermic or exothermic process: breaking solute-solute interactions A. endothermic B. exothermic

A. endothermic

Explain why lizards become sluggish in cold weather. How is this phenomenon related to chemistry? a. There is no relationship to chemistry. b. N/A. Reptiles are warm-blooded creatures. c. Cold reptiles move faster, due to extra energy. d. Cold reptiles are lethargic, unable to move very quickly.

d. Cold reptiles are lethargic, unable to move very quickly.

What is the conjugate acid in this reaction? HC2H3O2(aq) + H2O(l) <--> H3O+ + C2H3O2-(aq) a. HC2H3O2 b. C2H3O-2 c. H2O d. H3O+

d. H3O+

Calculate the boiling point of a 2.97 m aqueous sucrose solution. DeltaT = m x Kb Kb = 0.512 degrees C/ m A. 102.65 B. 98.48 C. 101.52 D. 101.84

C. 101.52

Consider the given acid ionization constants. Identify the strongest conjugate base. Acid. Ka HF(aq). 3.5X10^-4 HC7H5O2(aq). 6.5x10^-5 HClO2(aq). 1.1x10^-2 HC2H3O2(aq). 1.8x10^-5 A. F- (aq) B. C7H5O2- (aq) C. C2H3O2- (aq) D. ClO2- (aq)

C. C2H3O2- (aq)

Which compound has the highest boiling point? Potassium fluoride (KF), methane (CH4), or bromoform (CHBr3)? A. CH4 B. CHBr3 C. KF

C. KF

What is the main component of glass? A. SiC B. Al2O3 C. SiO2 D. CaF2

C. SiO2

Identify the types of interactions between the following species: Ions of NaCl A. Solute-Solute B. Solvent-Solvent C. Solute-Solvent

C. Solute-Solvent

Identify the types of interactions between the following species: Ions of NaCl and Water Molecules A. Solute-Solvent B. Solute-Solute C. Solvent-Solvent

C. Solvent-Solvent

Which choice is not true of a liquid in a glass capillary with a convex meniscus? A. The liquid has strong cohesive forces. B. The liquid level will be lower inside the capillary when a capillary is inserted into a bowl of the liquid. C. The behavior of the liquid is driven by strong interactions with the capillary glass. D. The liquid will have a convex meniscus as it moves in the capillary.

C. The behavior of the liquid is driven by strong interactions with the capillary glass.

What type(s) of intermolecular force is/are exhibited by sulfur dioxide, SO2? A. dipole-dipole forces only B. both ion-dipole and dipole-dipole forces C. both dipole-dipole forces and dispersion forces D. dispersion forces only

C. both dipole-dipole forces and dispersion forces

The cations of NaCl A. form a simple cubic unit cell B. fill the octahedral holes C. fill the cubic holes D. fill every other tetrahedral hole

C. fill the cubic holes

Use the valence bond theory to devise a hybridization and bonding scheme for CO2. The molecule is __________ hybridized. A. sp3 B. sp3d C. sp D. sp2

C. sp

For each of the following molecules, would you expect greater solubility in water or in hexane? HO--CH2--CH2--OH A. both B. neither C. water D. hexane

C. water

An experiment carries out the reaction A -> products at three different initial concentrations of A and the initial reaction rate were measured, as indicated in the table. [A](M) Initial Rate (M/s) 0.15 0.010 0.30 0.040 0.45 0.090 Based on this data, what is the rate law for the reaction? a. Rate = k[A] b. Rate = k c. Rate = k[A]3 d. Rate = k[A]2

d. Rate = k[A]2

For the following reaction: 2Mg + O2 --> 2MgO, rate = [Mg][O2]^2 What is the overall reaction order? a. first order b. second order c. zero order d. Third order

d. Third order

Calculate the amount of heat (in kilojoules) required to vaporize 2.58 kg of water at its boiling point. Express the heat in kilojoules to three significant figures, rounding to the nearest tens. SHOW YOUR WORK HERE FOR FULL CREDIT

5830 kJ H2O

Find the percent ionization of a 0.250 M solution of HC2H3O2. Ka for HC2H3O2 is 1.8x10^-5 percent ionization = [H+]/[HC2H3O2]X100 A. 0.85% B. 15% C. 0.15% D. 85%

A. 0.85%

What is the maximum number of bonds that can form in a molecule with a central atom containing five electrons in sp3 hybrid orbitals? A. 3 B. 1 C. 4 D. 2

A. 3

What are the electron and molecular geometries, respectively, for hydrogen sulfide, H2S? A. Electron geometry is tetrahedral. Molecular geometry is bent. B. Electron geometry is bent. Molecular geometry is tetrahedral. C. Electron geometry is linear. Molecular geometry is bent. D. Electron geometry is linear. Molecular geometry is linear.

A. Electron geometry is tetrahedral. Molecular geometry is bent.

This plot shows the rate of the decomposition of SO2Cl2 into SO2 and Cl2 as a function of the concentration of SO2Cl2. What is the order of the reaction? Linear, slope = 1. a. first order b. second order c. zero order d. Order cannot be determined without more information.

A. First order

Rank silicon, boron, and phosphorus in order of decreasing number of valence electrons. Phosphorus has the: A. Most B. Middle C. Least

A. Most

Is the following likely to be soluble in water? Hexane (C6H14) A. No, not soluble B. Yes, soluble

A. No, not soluble

Which statement best describes the polarity of CH2Br2? A. The molecule is always polar. B. Depending on the arrangement of outer atoms, this molecule could be polar or nonpolar. C. The molecule is always nonpolar.

A. The molecule is always polar.

Beer, an alcoholic beverage, is a solution composed primarily of water with an ethanol content of about 7%. Identify the solute and the solvent in beer. A. Water is the solvent, and ethanol is the solute. B. Ethanol is the solvent, and water is the solute. C. You cannot determine which is the solute and which is the solvent because you do not know whether the ethanol was dissolved in the water or the water was dissolved in the ethanol. D. Both water and ethanol are solvents because because solutes must be a solid substance.

A. Water is the solvent, and ethanol is the solute.

By drawing molecular an orbit diagram for B2, predict whether this homonuclear diatomic molecule is magnetic. A. Yes, it is magnetic B. No, it is not magnetic

A. Yes, it is magnetic

Is the following likely to be soluble in water? LiBr A. Yes, soluble B. No, not soluble

A. Yes, soluble

In the liquid state, which of the following would be excepted to have the greatest surface surface tension: ammonia (NH3), dimethyl ether (CH3OCH3), or butane (CH3CH2CH2CH3)? Hint 1. Factors that influence surface tension A. ammonia (NH3) B. dimethyl ether (CH3OCH3) C. Ammonia and dimethyl ether are probably similar because both exhibit hydrogen bonding. D. butane (CH3CH2CH2CH3)

A. ammonia (NH3)

Which of the molecules below will be polar? CS2, BF3, SO2, CH3Br A. both SO2 and CH3Br B. CH3Br only C. both BF3 and CH3Br D. CS2 only

A. both SO2 and CH3Br

Atoms in unit cells may be positioned in corners, along edges, on faces, or centered in the body of the unit cell. All eight of the atoms shown in the simple cubes diagram are in which position? A. corner B. body C. face D. edge

A. corner

Which of the temperatures below is most likely to be the boiling point of water at 880 torr?You don't need to calculate anything to answer this question. A. 92 degrees Celsius B. 105 degrees Celsius C. 70 degrees Celsius D. 100 degrees Celsius

B. 105 degrees Celsius

What is the value of the bond angles in AlCl3? A. 90 degrees B. 109.5 degrees C. 120 degrees D. 180 degrees

B. 109.5 degrees

The solubility of a gas in a liquid solvent at a given temperature is directly proportional to the partial pressure of the gas over the solution. This relationship is expressed by a simple equation known as Henry's Law: S=kxp Calculate the solubility (in M units) of ammonia gas in water at 298 K and a partial pressure of 7.50 bar. The Henry's Law constant is in atmospheres, so you must convert pressure before proceeding. A. 7.40 M B. 429 M C. 58.7 M D. 515 M

B. 429 M

An x-ray beam of unknown wavelength is diffracted from a NaCl surface. If the interplanar distance in the crystal is 376 pm, and the angle of maximum reflection is found to be 7.20 degrees, what is the wavelength of the x-ray beam? (Assume n=1.) Express your answer in terms of picometers. A. 71.4 B. 94.3 C. 376 D. 285

B. 94.3

Consider the Lewis structure for PCl3. A. 120 degrees B. < 109.5 degrees C. 180 degrees D. 90 degrees

B. < 109.5 degrees

Identify the Brønsted-Lowry acid, the Brønsted-Lowry base, the conjugate acid, and the conjugate base in this reaction. The underlined species is the: C5H5N(aq) + H2O(l) --> C5H5NH+(aq) + OH-(aq) C5H5N(aq) A. Brønsted-Lowry acid B. Brønsted-Lowry base C. conjugate acid D. conjugate base

B. Bronsted-Lowry base

Which of the following substances is/are polar covalent? A. MgI2 B. C2H5OH C. CuCl2

B. C2H5OH

Which has the larger dipole moment? A. CH4 B. CHBr3

B. CHBr3

What is graphene? A. Graphene is a cube of graphite consisting of six-atoms B. Graphene is one-atom thick graphite C. Graphene is a two-atom-thick graphite D. Graphene is a rectangle of graphite consisting of eight-atoms

B. Graphene is one-atom thick graphite

Why is graphene unique? A. Graphene is the thickest and strongest known material. It conducts heat and electricity, it is transparent, and it is completely impermeable to all substances, including helium. B. Graphene is the thinnest and strongest known material. It conducts heat and electricity, it is transparent, and it is completely impermeable to all substances, including helium. C. Graphene is the thinnest and strongest known material. It does not conduct heat and electricity, it is transparent, and it is completely impermeable to all substances, including helium. D. Graphene is the thinnest and weakest known material. It conducts heat and electricity, it is transparent, and it is completely impermeable to all substances, including helium.

B. Graphene is the thinnest and strongest known material. It conducts heat and electricity, it is transparent, and it is completely impermeable to all substances, including helium.

Classify the element as metal or nonmetal: Carbon A. Not enough information B. Nonmetal C. Metal

B. Nonmetal

A crystalline solid has a high melting point and is known to be held together with covalent bonds. This solid is an example of __________. A. an ionic solid B. a network covalent solid C. a molecular solid D. a metallic solid

B. a network covalent solid

For the following reaction: 2Mg + O2 --> 2MgO, rate = [Mg][O2]^2 What would happen to the rate if [Mg] were doubled? The rate would: a. stay the same. b. double. c. triple. d. quadruple.

B. double.

Classify the process as an endothermic or exothermic process. A. exothermic B. endothermic

B. endothermic

Which is the strongest intermolecular force? Choose only one answer. A. dipole-dipole forces B. hydrogen bonding C. dispersion forces

B. hydrogen bonding

Classify the element as a metal or nonmetal. A. Not enough information B. metal C. nonmetal

B. metal

According to the Valence Shell Electron Pair Repulsion (VSEPR) theory, a molecule or ion that has five electron groups around the central atom will have what basic electron geometry? A. octahedral B. trigonal bipyramidal C. tetrahedral D. pentagonal planar

B. trigonal bipyramidal

A solution contains 36.3 g of glucose (C6H12O6) dissolved 0.500 L of water. What is the molarity of the solution? (Assume a density of 1.00 g/mL for water.) (molality is moles/kg) A. 0.512 B. 0.124 C. 0.249 D. 0.403

D. 0.403

What is the value of the bond angles in SiCl4? A. 120 degrees B. 180 degrees C. 90 degrees D. 109.5 degrees

D. 109.5 degrees

How many atoms are in the body-centered cubic unit cell? A. 5 B. 4 C. 1 D. 2

D. 2

What is the bond order of C2-? bond order = (bonding electrons - antibonding electrons) / 2 A. 1.5 B. 2 C. 1 D. 2.5

D. 2.5

Chromium crystallizes with a body-centered cubic unit cell. The radius of a chromium atom is 125 pm. Calculate the density of solid crystalline chromium in grams per cubic centimeter. Density = m/v. The atomic mass is (51.996 g/mol) (2 atoms per cell for a body-centered cubic unit cell). Avogadro's number = 6.022x10^23atoms/mol. The volume of a cube is the edge length raised to the third power (l^3), where the edge length is related to the radius of cell unit cell as follows: l=4r/square root of 3 A. 6.59 B. 7.96 C. 8.17 D. 7.18

D. 7.18

Which of the substances below is/are examples of colloids? A. All three are colloids. B. mayonnaise only C. shaving cream only D. Both shaving cream and mayonnaise are colloids.

D. Both shaving cream and mayonnaise are colloids.

Based on the general trends on intermolecular forces, rank C2H5OH, HCl, and C3H6 in order of increasing boiling point. A. C2H5OH < HCl < C3H6 B. C3H6 < C2H5OH < HCl C. HCl < C3H6 < C2H5OH D. C3H6 < HCl < C2H5OH

D. C3H6 < HCl < C2H5OH

Which compound do you expect to be miscible with octane (C8H18)? A. NH3 B. H2O C. CH3OH D. CBr4

D. CBr4

An aqueous solution is saturated with both a solid and a gas at 5 degrees Celsius. What is likely to happen if the solution is heated to 85 degrees Celsius? A. Some gas will bubble out of the solution and some solid will precipitate out of the solution. B. Some solid will precipitate out of solution. C. More gas will dissolve and more of the solid will dissolve. D. Some gas will bubble out of solution and more solid will dissolve.

D. Some gas will bubble out of solution and more solid will dissolve.

Determine the pH at the equivalence point for the titration of 40.0 mL of 0.1 M HNO2 by 0.200 M KOH (Example 16.7). (The pKa of nitrous acid is 3.36.) Express the pH to three decimal places. pH=14-pOH=14+log[OH-]equiv=14+logKb[A-]equiv Essentially, the pH of the solution at the equivalence point is solved in the same way you would calculate the pH of a weak base solution. Beyond the equivalence point, you need to take into account the additional OH- in solution contributed by the strong base. a. 8.092 b. 7.00 c. 6.351 d. 9.518

a. 8.092

Which statement below is true? a. Acids can dissolve many metals. b. Acids are classified as alkaloids. c. Bases turn blue litmus paper red. d. Bases have a sour taste.

a. Acids can dissolve many metals.

Identify the Brønsted-Lowry acid, the Brønsted-Lowry base, the conjugate acid, and the conjugate base in this reaction. The underlined species is the: C5H5N(aq) + H2O(l) --> C5H5NH+(aq) + OH-(aq) H2O(l) a. Brønsted-Lowry acid b. Brønsted-Lowry base c. conjugate acid d. conjugate base

a. Brønsted-Lowry acid