Senior Chem Past Exam

Which statement is correct about the reaction between methane and chlorine?

It involves homolytic fission and Cl· radicals.

Which product is formed by the reaction between CH2=CH2 and HBr?

CH3CH2Br

Which compound is a member of the same homologous series as 1-chloropropane?

1-chlorobutane

Which formula is a correct representation of pentane?

CH3(CH2)3CH3

Which of the structures below is an aldehyde?

CH3CH2CHO

What product results from the reaction of CH2=CH2 with Br2?

CH2BrCH2Br

What is the IUPAC name for CH3CH2CH(CH3)2?

2-methylbutane

Which substance(s) could be formed during the incomplete combustion of a hydrocarbon?

Carbon and carbon monoxide

Which formulas represent butane or its isomer?

CH3(CH2)2CH3 and CH3CH(CH3)CH3

Which is the correct description of the following reaction? C2H4 + H2O → C2H5OH

Addition

Which statement about neighboring members of all homologous series is correct?

They differ by a CH2 group.

Which type of compound must contain a minimum of three carbon atoms?

A ketone

Which of the following molecules is polar?

cis-2-butene

A compound with the molecular formula C3H6 could be

cyclopropane

When a racemic mixture is separated by chemical reactions it leads to

isolation of enantiomers

Which of the following molecules is most likely to undergo an SN1 reaction?

(CH3CH2)3CBr

Which of the following is NOT a feature of SN2 reactions

a carbocation intermediate

E1 reactions are characterized by all of the following EXCEPT

nucleophilic attack on a carbocation intermediate

Alkane halogenation reactions proceed by which of the following mechanisms?

free radical substitution

Which of the following radical reactions is an example of a free radical propagation step?

Br· + CH2=CHCH2 → CH3CHBrCH3

A substitution reaction involving methyliodide would most likely demonstrate which of the following?

an SN2 reaction mechanism

Decide if the following compounds contain chiral carbons. Identify the chiral carbon if present. CH3CH2CHOHCH2CH3

yes

Which product is formed from the reaction between CH3COOH and CH3CH2OH?

CH3COOCH2CH3

In which pair do both types of compounds take part in hydrogen bonding?

Alcohols (alkanols) and amines

Which product is formed in the reaction between ethene and bromine?

CH2BrCH2Br

Organic acids contain the

carboxyl group

Which is a correct description of a free radical?

It has an unpaired electron and is formed by the homolytic fission of a covalent bond.

Alcohols (alkanols) can undergo dehydration reactions. Which product could be obtained from the dehydration of ethanol?

Ethene

What is the correct order of reaction types in the following sequence? C2H5Cl → C2H5OH → CH3COOH → CH3COOCH3

substitution, oxidation, esterification

Which of the compounds A–D is an ether?

CH3OCH2CH3

Which of the compounds A–D is an aldehyde?

CH3CH2CHO

Which of the compounds A–D can be formed by the oxidation of ethanol?

CH3CHO

Which of the compounds A–D can be formed by the oxidation of 2-propanol?

CH3COCH3

Which of the following pairs represent members of an homologous series?

C3H7COOH and C4H9COOH

How many different isomers have the formula C4H10?

2

What is the final product formed when CH3CH2OH is refluxed with acidified potassium dichromate (VI)?

CH3COOH

What are alkanes called when atoms of fluorine, chlorine, bromine, or iodine are substituted for hydrogen atoms?

halogenoalkanes

Which formula is the most useful in distinguishing isomers?

structural formula

Which group of organic compounds can be considered derivatives of ammonia NH3?

amine

Esters are frequently used

in perfumes and flavorings

What is the splitting pattern expected in the HNMR spectrum for the hydrogen atoms in bold print in CH3COCH2CH3?

quartet

In order for a reagent to behave as a nucleophile it must have

a nonbonding electron pair

Which statement about members of a homologous series is true?

each differs from its nearest neighbors by 14 amu

How many structurally distinct (different) sets of hydrogens are present in (CH3)2CCH2OCH2?

3

How would the bond strength of the C=C double bond in an alkene compare to that of a C–C single bond in the corresponding alkane?

stronger than, but less than twice as strong

What is the molecular formula of dioxin?

C12H4Cl4O2

Which of the following compounds has no isomer?

CH2=CHCl

Which of the following statements about carbon is not correct?

carbon expands its valence shell

A tertiary carbocation (carbonium ion) is more stable than either a secondary or primary carbocation because

it possesses three electron-donating substituent groups

Which compound is a likely product from addition of Cl2 to 1-butene?

CH3CHClCHClCH3

Enantiomers are

stereoisomers having non-identical mirror image configurations

In the following diagram of a light wave what distance is defined as the wavelength?

1 to 3

Four major spectroscopic tools are listed below. Which makes use of the longest wavelength radiation?

proton NMR

The 1H NMR of 1,1-dibromoethane consists of two well-separated signals. Which description is correct?

large doublet and small quartet

Which spectroscopic tool would be best for distinguishing a sample of 1,2,2-trichloropropane from 1,1,2-trichloropropane?

proton NMR

The 1H NMR spectrum of diethyl ether (CH3CH2OCH2CH3) shows

two peaks, one triplet and one quartet

A saturated hydrocarbon

has the formula CnH2n+2

Which of the following is not the name of a hydrocarbon side-chain?

diethyl

Compounds with the same molecular formulas but different structural formulas are

isomers

Name the following: CH3CH2C(CH3)2H

2-methylbutane

Which of the following isomers of C5H12 has the lowest boiling point?

(CH3)4C

Incomplete combustion of alkanes produces all of the following except

carbon dioxide

A form of bond breakage in which both bonded atoms end up with one of the shared electrons is called

homolytic fission

Which is a possible product of the chlorination of ethane in the presence of ultraviolet light?

C2H5Cl

The reaction of an alkane with chlorine gas in the upper atmosphere is dependent upon the presence of

ultraviolet light

When free radicals cause the formation of other free radicals, this is referred to as

propagation

The name of CH2=CHCH2CH3 is

1-butene

The product of the reaction of H2 and CH2=CH2 is

CH3CH3

The reactant required to form CH3CH2Cl from CH2=CH2 is

HCl

Bromine water is added to a colorless solution of an organic compound which turns yellowish upon the addition, but slowly becomes colorless over time. The organic compound is a/an

alkene

Teflon is a type of

polymer

Name the following: CH3CHOHCH3

2-propanol

Identify the type of organic compound shown: CH3COCH3

ketone

Identify the type of organic compound shown: CH3COOCH3

ester

Identify the type of organic compound shown: (CH3)3N

amine