Chem test 1-8
What is the IUPAC name of the following compound?
(S)-3-Chloro-6-ethyloctane
Using the bond dissociation energies given, calculate DH° for the following reaction.
+22 KJ/mol
What is the IUPAC name for the following compound?
1,3-Dimethylcyclopentane
What is the IUPAC name for the following compound?
1-Cyclopentylhexane
What is the IUPAC name for the following compound?
1-Ethyl-3-methylcyclohexane
What is the approximate H-C-O bond angle in formaldehyde, H2CO?
120°
What is the approximate bond angle for the C-C-N bond in acetonitrile, CH3CN? 90° 109.5° 120° 180°
180°
What is the ground-state electronic configuration of a fluorine atom?
1s2, 2s2, 2p5
How many constitutional isomers are there for a molecule having the molecular formula C2H6O?
2
How many transition states are present in the reaction in the energy diagram?
2
Which of the following compounds has primary, secondary, tertiary, and quaternary carbon atoms? 2,2,3-Trimethylpentane 2,2-Dimethylpentane Pentane 2-Methylpentane
2,2,3-Trimethylpentane
Which of the following compounds has only primary, secondary, and tertiary carbon atoms? Pentane 2,2,3-Trimethylpentane 2,2-Dimethylpentane 2-Methylpentane
2-Methylpentane
Which of the following compounds has primary, secondary, and tertiary hydrogen atoms? 2-Methylpentane 2,2-Dimethylpentane Pentane Hexane
2-Methylpentane
Which of the following compounds has primary, secondary, and tertiary hydrogen atoms? Hexane Pentane 2-Methylpentane 2,2-Dimethylpentane
2-Methylpentane
How many isomers can be drawn (constitutional and stereoisomers) for dimethycyclopropane? 3 6 4 2
4
What is the IUPAC name for the following compound?
4-Ethyl-3,6-dimethyloctane
What is the IUPAC name for the following compound?
4-Ethyl-5-methyloctane
What is the name of the following compound?
4-ethyl-3-methylheptane
What is the name of the following compound?
4-isopropyloctane
How many constitutional isomers are there with the molecular formula C6H14?
5
How many cycloalkane constitutional isomers (excluding stereoisomers) are there with molecular formula C5H10?
5
How many different isomers are there for a compound having the molecular formula C3H6O?
7
Which of the following statements is not true? A half-headed curved arrow shows the movement of an electron pair. In polar reactions, a nucleophile reacts with an electrophile. Carbocations are electrophiles. Carbanions are nucleophiles.
A half-headed curved arrow shows the movement of an electron pair.
Which of the following statements is true? With one tetrahedral stereogenic center, a molecule may or may not be chiral. With two or more stereogenic centers, a molecule is always chiral. Achiral molecules usually contain a plane of symmetry. Chiral molecules usually contain a plane of symmetry.
Achiral molecules usually contain a plane of symmetry.
What kind of reaction does the conversion of A to B represent?
Addition reaction.
Which of the following statements about a Brønsted-Lowry base is true? The net charge may be zero or positive. The net charge may be zero, positive, or negative. All Brønsted-Lowry bases contain a proton. All Brønsted-Lowry bases contain a lone pair of electrons or a π bond.
All Brønsted-Lowry bases contain a lone pair of electrons or a π bond
Which of the following statements about a Brønsted-Lowry base is true? The net charge may be zero, positive, or negative. All Brønsted-Lowry bases contain a lone pair of electrons or a π bond. All Brønsted-Lowry bases contain a proton. The net charge may be zero or positive.
All Brønsted-Lowry bases contain a lone pair of electrons or a π bond
Which of the following statements about a Brønsted-Lowry base is true? The net charge may be zero or positive. The net charge may be zero, positive, or negative. All Brønsted-Lowry bases contain a proton. All Brønsted-Lowry bases contain a lone pair of electrons or a π bond.
All Brønsted-Lowry bases contain a lone pair of electrons or a π bond.
What is the relationship between the following compounds?
Diastereomers
Which compound would you predict to be highest in energy?
B
Which reaction is fast and has Keq = 1?
B
Which of the following statements is true? When DH° is negative, more energy is needed to break bonds than is released in forming bonds. When DH° is positive, more energy is released in forming bonds than is needed to break bonds. Bond dissociation energies increase down a column of the periodic table. Bond dissociation energies decrease down a column of the periodic table.
Bond dissociation energies decrease down a column of the periodic table.
Which of the following statements explain why HBr is a stronger acid than HF? Br- is less stable than F- because Br- is less electronegative than F-. Br- is more stable than F- because Br- is larger than F-. Br- is less stable than F- because Br- is larger than F-. Br- is more stable than F- because Br- is less electronegative than F-.
Br- is more stable than F- because Br- is larger than F-.
Which atomic orbitals overlap to form the carbon-carbon s and p bonding molecular orbitals of ethylene, H2C=CH2? Csp3 + Csp3, and Csp2 + Csp2 Csp3 + Csp3, and C2p + C2p C. Csp2 + Csp2, and C2p + C2p D. Csp2 + Csp2, and Csp2 + Csp2
C. Csp2 + Csp2, and C2p + C2p
What is the molecular formula of a cycloalkane that has six carbon atoms?
C6H12
Which of the following ranks the compounds in order of increasing basicity, putting the least basic first? CH4 < CH3OH < CH3NH2 CH3OH < CH3NH2 < CH4 CH3NH2 < CH3OH < CH4 CH4 < CH3NH2 < CH3OH
CH4 < CH3OH < CH3NH2
Which of the following molecules has the smallest dipole moment? NH3 CO2 HCl H2O
CO2
Which atomic orbitals overlap to form the C-H s bonding molecular orbitals of ethane, CH3CH3? C2p + H1s Csp + H1s Csp2 + H1s Csp3 + H1s
Csp3 + H1s
Which of the following statements about alkanes is true? Acyclic alkanes have the general molecular formula CnH2n. Alkanes are aliphatic hydrocarbons having only C-C and C-H p bonds. Acyclic alkanes contain carbons joined in one or more rings. Cyclic alkanes have two fewer H atoms than acyclic alkanes with the same number of carbons.
Cyclic alkanes have two fewer H atoms than acyclic alkanes with the same number of carbons
Which of the following cycloalkanes has the most angle strain? Cyclopentane Cyclopropane Cyclobutane Cyclohexane
Cyclopropane
Which of the following statements about the conformations of acyclic alkanes is true? A staggered conformation with two larger groups 180° from each other is called gauche. Gauche conformations are generally higher in energy than anti conformations. Staggered conformations are at energy maxima and eclipsed conformations are energy minima. A staggered conformation with two larger groups 60° from each other is called anti.
Gauche conformations are generally higher in energy than anti conformations.
Which of the following species is the conjugate base of the hydronium ion, H3O+? HO- H3O H2O H2O-
H2O
Which of the following species cannot act as both a Brønsted-Lowry acid and base? H2PO4- HCO3- HO- HSO4-
HO-
Which of the Keq corresponds to the lowest value of DG°?
Keq = 10-1
For which of the following reactions is ΔS° a positive value?
I
What is the condensed formula of the compound below?
I
Which of the following is the most stable conformation of the following compound?
I
Which of the following structures has a different configuration from the other three?
I
Rank the following compounds in order of increasing strength of intermolecular forces, putting the molecule with the weakest intermolecular force first.
I < III < II
Rank the following atoms in order of increasing electronegativity, putting the least electronegative first.
I < IV < II < III
What is the nucleophilic site in the following compounds?
I = Oxygen; II = π electrons in bond; III = nitrogen
Rank the following alkanes in order of decreasing boiling point, putting the alkane with the highest boiling point first
I > III > II
Consider the following structures I-IV. Which two species represent constitutional isomers?
I and III
Which of the following molecules are aliphatic hydrocarbons?
I and III
Which of the following conformers has the highest energy?
II
Which of the following molecules has a plane of symmetry?
II
Which of the following resonance structures is the least important contributor to the resonance hybrid of the formate anion, HCOO—?
II
Rank the following conjugate bases in order of increasing basicity, putting the least basic first.
II < I < III
Which of the following correctly matches the molecules to the names of the functional group? I. CH3NH2 Amide II. CH3SCH3 Sulfide III. CH3CONH2 Amine IV. CH3CO2CH3 Ester
II and IV
Which of the following Lewis structures is correct?
II, III
Follow the curved arrows to draw the second resonance structure for the ion below.
III
Which is the conjugate acid in the following reaction?
III
Which of the following is the highest energy conformer of 2,3-dimethylbutane?
III
Rank the following compounds in order of increasing acidity, putting the least acidic first.
III < IV < I < II
Rank the following compounds in order of decreasing acidity, putting the most acidic first
III > IV > II > I
Rank the following compounds in order of decreasing acidity, putting the most acidic first.
III > IV > II > I
Rank the following groups in order of decreasing priority according to the Cahn-Ingold-Prelog system.
III > IV > II > I
Which of the following alkyl halides is a vinyl alkyl halide?
IV
Which of the following chair conformations represents trans-1,3-dimethylcyclohexane?
IV
Rank the following in order of increasing leaving group ability, putting the worst leaving group first.
IV < II < III < I
Arrange the following bonds in decreasing order of ionic character, putting the most ionic first.
IV > III > II > I
Which of the Keq corresponds to the most negative value of DG°?
Keq = 10E3
Which of the following statements is not true? In polar protic solvents, nucleophilicity decreases down a column of the periodic table as the size of the anion increases. Polar protic solvents solvate both cations and anions. Polar protic solvents are capable of intermolecular hydrogen bonding. Nucleophilicity is affected by the solvent used in a substitution reaction.
In polar protic solvents, nucleophilicity decreases down a column of the periodic table as the size of the anion increases.
What is the direction of equilibrium when acetylene (C2H2) reacts with ethoxide (CH3CH2O-) in an acid-base reaction?
Left
Which of the following statements about Lewis acids is true? Lewis acids are proton donors. Lewis acids are electron pair acceptors. Lewis acids are proton acceptors. Lewis acids are electron pair donors.
Lewis acids are electron pair acceptors.
What is the role of methylchloride (CH3Cl) in the following reaction?
Lewis base
Which of the following statements about Brønsted-Lowry acids and bases is true? Gain of a proton by an acid forms its conjugate base. Loss of a proton from a base forms its conjugate acid. Loss of a proton from an acid forms its conjugate base. Brønsted-Lowry acid-base reactions always result in the transfer of a proton from a base to an acid.
Loss of a proton from an acid forms its conjugate base
Which of the following is the strongest base? CH3COCH3 H2O NH3 CH3COOH
NH3
In which of the following ions does carbon have a formal charge?
None of these
Which of the following structures has the R configuration?
Only I and II
If the conversion of A to B is slow and B to C is fast, what is the rate equation for this reaction?
Rate = k[(CH3)2CHCl]
Which of the following concepts can be used to explain the difference in acidity between acetic acid (CH3COOH) and ethanol (CH3CH2OH)? Size Electronegativity Resonance Hybridization
Resonance
Which of the following statements about resonance structures is not true? There is no movement of electrons from one form to another. Resonance structures are in equilibrium with each other. Resonance structures are not isomers. Resonance structures differ only in the arrangement of electrons.
Resonance structures are in equilibrium with each other.
For the following reaction, use the identity of the alkyl halide and nucleophile to determine which substitution mechanism occurs. Then determine which solvent affords the faster reaction.
SN2, DMF
What is the relation between the following pair of compounds? Stereoisomers Constitutional isomers Not isomers of each other Identical molecules
Stereoisomers
What is the relationship between the following two compounds?
Stereoisomers
Which of the following statements about the solubility of organic compounds in H2O is true? For an organic compound with one functional group that contains an O or N atom, the compound is water soluble only if it has 35 carbons. The non-polar part of a molecule that is not attracted to water is said to be hydrophilic. The non-polar part of a molecule that is not attracted to water is said to be hydrophobic. The polar part of a molecule that can that can bond hydrogen to water is said to be hydrophobic.
The non-polar part of a molecule that is not attracted to water is said to be hydrophobic.
Consider the reaction (CH3)3CBr + CH3CH2OH →(CH3)3COCH2CH3 + HBr Experimentally one finds that if the concentration of (CH3)3CBr is tripled, the rate of the reaction triples. One also finds that if the concentration of CH3CH2OH is doubled, the rate of the reaction is unchanged. Which of the following correctly describes the kinetics of this reaction? The reaction is third order in (CH3)3CBr. The reaction is first order in CH3CH2OH. The reaction is first-order overall. The reaction is second-order overall. none of the above
The reaction is first order overall.
Which of the following statements is true? A fast reaction has high activation energy. The size of the activation energy tells us about the reaction mechanism. A slow reaction has low activation energy. The size of the activation energy tells us about the reaction rate.
The size of the activation energy tells us about the reaction rate.
Which of the following statements about acid strength is true? The stronger the acid, the larger the pKa. The stronger the acid, the smaller the Ka. The stronger the acid, the further the equilibrium lies to the left. The stronger the acid, the smaller the pKa.
The stronger the acid, the smaller the pKa.
Which of the following statements about acid strength is true? The stronger the acid, the further the equilibrium lies to the left. The stronger the acid, the smaller the pKa. The stronger the acid, the larger the pKa. The stronger the acid, the smaller the Ka.
The stronger the acid, the smaller the pKa.
What is the common name of the following alkyl group?
sec-Butyl
Which of the following correctly expresses the standard Gibbs free energy change of a reaction in terms of the changes in enthalpy and entropy?
ΔG° = ΔH° - TΔS°
