PT LAB AND ORG CHEM

126問 • 3ヶ月前

Liane

通報

問題一覧

Which of the following is NOT a typical characteristic of organic compounds?

High melting and boiling points

What is the IUPAC name for the following structural formula: CH3CH2C(CH3)CHCH(CH3)2 ?

3,3,5-trimethylhexane

Which of the following compounds contains the fewest hydrogen atoms?

Propyne

Which suffix is commonly used to indicate the presence of a ketone functional group?

-one

A molecule has the formula C2H6O. Which of the following functional groups could it contain? I. Alcohol II. Ketone

I only (Alcohol)

Which of the following is the correct IUPAC name for the alkane whose longest chain has eight carbons with methyl groups at C-2 and C-3 and an ethyl group at C-4?

4-ethyl-2,3-dimethyloctane

Which of the following is NOT a valid representation of 3-methyl-1-butene?

CH3-CH=CH-CH2-CH3

What is the molecular formula of 3-methyl-1-butene?

C5H10

How many constitutional isomers are possible for the molecular formula C5H12?

How many distinct branched constitutional isomers exist for the formula C4H10?

Which of the following statements about covalent bonding is true?

A σ bond has cylindrical symmetry about the bonding axis.

Which types of bonds are formed by a carbon atom with sp hybridization?

Two π bonds and two σ bonds.

What is the bond angle and molecular geometry around each carbon atom in ethene (CH2=CH2)?

120°, trigonal planar.

What is the hybridization of the oxygen atom in methanol (CH3OH)?

sp3

Which of the following types of covalent bonds is generally the strongest?

σ bond

Which of the following is NOT chiral?

A molecule with a plane of symmetry

Which of the following statements is true for an optically active compound?

The molecular configuration is chiral.

Which of the following compounds can exist as cis and trans (geometric) isomers?

1-Chloropropene

Which of the following is a necessary feature for a compound to have enantiomers?

Neither a double bond nor a ring is necessary; the necessary feature is chirality (e.g., a stereogenic center or another element of asymmetry).

A racemic mixture consists of equal amounts of:

Enantiomers

Which of the following is NOT an addition reaction?

Dehydration

In which type of reaction does one sigma bond break and another form at the same carbon atom?

Substitution

Which of the following best describes an electrophile?

An electron-deficient species that accepts electron pairs

Which of the following is a nucleophile?

CH3− (methyl anion)

Which of the following statements is FALSE?

A nucleophile must always be negatively charged.

Liquefied petroleum gas (LPG) is mainly composed of which pair of hydrocarbons?

Propane and Butane

Which of the following hydrocarbons has the lowest boiling point?

CH4 (methane)

Compared to ionic compounds of similar molar mass, hydrocarbons typically have:

Neither higher water solubility nor higher melting points (Neither I nor II)

What are the products of the complete combustion of an alkane?

CO2 and H2O

Alkanes undergo halogenation primarily through which mechanism?

Free radical substitution

Alkenes and alkynes, because they contain π bonds, typically undergo which type of reaction?

Electrophilic addition

Which of the following reactions can reduce an alkene to form an alkane?

Hydrogenation

What is the major product of the addition of Cl2 to 1-butene?

1,2-Dichlorobutane (CH2Cl-CHCl-CH2-CH3)

Which of the following reagent systems will convert an alkene to a bromohydrin (adds Br and OH across the double bond)?

Br2, H2O

All of the following reactions convert alkenes to alcohols except:

Ozonolysis

Which of the following statements about Markovnikov's rule is true?

The electrophile (e.g., H+) adds to the carbon with more hydrogens

Propene is treated with cold, dilute KMnO4 (syn dihydroxylation). What is the major product?

1,2-Propanediol (propane-1,2-diol)

In an alkene, the π bond is primarily responsible for which property?

Reactivity with electrophiles

Which of the following demonstrates anti-Markovnikov hydration of an alkene?

Hydroboration–oxidation of alkenes

Which of the following alkynes is a terminal alkyne?

CH≡C–CH2–CH3 (1-butyne)

What is the position of the bromine atom relative to the methyl group in 3-bromotoluene?

meta

Aromatic compounds undergo substitution reactions instead of addition reactions because:

Substitution preserves the stability of the aromatic system.

Which of the following is an aromatic compound?

Styrene

AlCl3 is a catalyst used in the alkylation and acylation of aromatic compounds. It functions as:

A Lewis acid

What is the product of the Friedel–Crafts alkylation of nitrobenzene?

No reaction (Friedel–Crafts alkylation does not occur on nitrobenzene under normal conditions because the nitro group strongly deactivates the ring)

Freon is an example of a:

Alkyl halide (a halogenated alkane, e.g., chlorofluorocarbon)

What is the role of OH− (hydroxide ion) in typical substitution reactions?

Nucleophile (and often a base)

In the reaction of cyanide with 1-bromobutane in methanol, what is the role of cyanide?

A nucleophile

Through which mechanism does the reaction of a primary alkyl bromide with methoxide (NaOCH3 in CH3OH) typically proceed?

SN2

Which of the following chloroalkanes undergoes substitution with OH− exclusively by an SN1 mechanism?

tert-Butyl chloride ((CH3)3CCl)

Which of the following lists of compounds is arranged in order of increasing boiling point?

2-methylbutane < n-pentane < butanone < butanol

Which of the following classes of compounds is generally the most volatile (has the lowest boiling points) for compounds of comparable molecular weight?

Ether

Which of the following types of alcohols react readily with acidic dichromate solution (K2Cr2O7 in aqueous H2SO4) by oxidation?

Primary alcohols

Aldehydes and ketones typically undergo which type of fundamental organic reaction?

Nucleophilic addition

Why are carboxylic acids generally more acidic than alcohols?

The carboxylate anion is stabilized by resonance.

Which of the following alcohols reacts most rapidly with HBr to give the corresponding alkyl bromide?

2-methyl-2-propanol (tert-butanol)

Which of the following C4 compounds is most soluble in water?

Butanoic acid (butyric acid)

Which of the following alkyl halides reacts most rapidly with water (hydrolysis) under typical conditions?

tert-Butyl chloride (2-chloro-2-methylpropane)

Which nitrogen-containing functional group contains a carbon–nitrogen triple bond?

Nitrile (–C≡N)

Which of the following nitrogen-containing functional groups can act as a weak base because of a readily available lone pair on nitrogen?

Amine

ISO/IEC 17025 is intended to ensure the technical competence and accuracy of results in which type of laboratories?

Testing and calibration laboratories

Which of the following best describes the function of a control sample in laboratory quality control?

To validate test accuracy using a sample with a known analyte concentration

What is the main purpose of using a spiked sample in analytical testing?

To assess method recovery and matrix effects by adding a known amount of analyte

Which component of the quality system is defined by ISO as the assembly of all planned and systematic actions necessary to provide confidence that a product, process, or service will meet quality requirements?

Quality Assurance

Which part of the quality management system is reactive and primarily focused on ensuring the quality of products or results, particularly those about to be released?

Quality Control

Which internal quality control tool is most appropriate for detecting gradual shifts or sudden changes in an analytical process?

Control chart (e.g., Shewhart or Levey–Jennings chart)

Which internal quality control tool is most appropriate for monitoring precision (random error) of an analytical method?

Replicate measurements

A laboratory performs multiple tests on the same sample to evaluate reproducibility and consistency of results. Which QC practice is being applied?

Running replicates

Which of the following laws regulates the use of chemical precursors and essential chemicals that may be used in the manufacture of illegal drugs, and applies to laboratories handling such substances?

RA 9165

Which law regulates the storage and handling of flammable and reactive chemicals in laboratories to prevent fire hazards?

RA 9514

Where is the best location to place a laboratory fume hood to ensure optimal performance and safety?

Away from air supply vents and diffusers

Which of the following are considered good practices when using a laboratory fume hood? (Select all that apply)

Position equipment and chemicals at least 6 inches (15 cm) inside the hood, Avoid sudden sash movements

Which of the following placement conditions is most likely to compromise the effectiveness of a fume hood?

Located next to an exterior door that remains open frequently

According to ANSI Z358.1-2014, what is the generally recommended minimum eye flushing duration when the chemical involved is unknown?

At least 15 minutes

Which chemical exposure typically requires the longest eye flushing time?

Strong alkalis

The area surrounding a safety shower or eyewash station should:

Remain clear of all items at all times and be marked with yellow and black floor tape to remind users to keep it clear

Which type of fire extinguisher is best suited for extinguishing fires involving energized electrical equipment (Class C fires), and why?

Carbon dioxide - because it displaces oxygen without conducting electricity

Under RA 9514, which class of fire extinguisher is typically recommended for fires involving flammable liquids and gases?

Class B - Foam or dry chemical extinguisher

According to the Department of Trade and Industry - Bureau of Philippine Standards, what is the color coding for a foam fire extinguisher?

Red body with no band

What are the components of the fire triangle?

Oxygen, fuel, heat

What is the main purpose of a Chemical Hygiene Plan (CHP) in the laboratory?

To ensure consistent, safe chemical handling and regulatory compliance

Which of the following best illustrates the purpose of labeling and signage in a laboratory safety system?

Alerts personnel to potential hazards and facilitates emergency response

Which statement best explains why relying solely on personal protective equipment (PPE) without integrating SOPs and ventilation systems is insufficient for ensuring laboratory safety?

PPE serves as the last line of defense and must be supported by systemic controls

A laboratory worker is setting up an experiment involving flammable solvents and open flame. Which type of lab coat is most appropriate?

Flame-resistant lab coat

Which combination of glove and lab coat would provide the most protection when working with concentrated acids and corrosive agents?

Neoprene gloves and a chemical-resistant lab coat

Which of the following PPE combinations is most appropriate when handling cryogenic liquids like liquid nitrogen?

Cryogenic gloves and a flame-resistant lab coat

Which type of respirator is most appropriate for protection against airborne particles such as dust, aerosols, and biological agents in low-hazard environments?

N95 respirator

Which combination of personal protective equipment (PPE) is most appropriate when handling highly toxic and corrosive chemicals that pose both splash and vapor inhalation risks?

Face shield with goggles and full-face respirator

Which of the following is the primary advantage of using a Powered Air-Purifying Respirator (PAPR) in a laboratory environment?

It supplies filtered air continuously while reducing breathing effort

Which type of goggles should be avoided when working with volatile chemicals because their design allows vapor entry?

Anti-fog goggles

In the GHS system, what does the skull and crossbones pictogram represent?

Acute toxicity (fatal or toxic)

Which laboratory hazard is most likely to result in injuries such as cuts or burns from hot surfaces and sharp instruments?

Physical hazard

A researcher is handling genetically modified organisms and disposing of biohazardous waste. Which set of safety measures is most appropriate?

Biosafety cabinet use, sterilization, and waste segregation

What type of hazards is represented by the GHS pictogram showing a flame symbol?

Flammable, self-reactive substances, and pyrophorics

What does the GHS health hazard pictogram (silhouette with a star on the chest) indicate?

Risk of long-term health effects like cancer or reproductive toxicity

Which of the following documents provides essential information about chemical hazards, safe handling, storage guidelines, and emergency procedures, and typically includes 16 standardized sections?

Safety Data Sheet

Which of the following is NOT typically listed as a special hazard in the white section of the NFPA 704 diamond?

FLAM (Flammable)

Which GHS pictogram indicates an environmental hazard?

Dead tree and fish — environmental hazard

What does the GHS corrosion pictogram (test tube pouring on hand and metal) indicate?

Corrosive chemical that can cause skin burns and eye damage

100

How many standardized sections does a Safety Data Sheet (SDS) typically include?

General Chem

General Chem

Laboratory

Laboratory

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Chromatography

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Eval Exam Lab and Org

Liane · 74問 · 3ヶ月前

Eval Exam Lab and Org

Mock Lab and Org

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PT GEN CHEM

PT GEN CHEM

問題一覧

Which of the following is NOT a typical characteristic of organic compounds?

High melting and boiling points

What is the IUPAC name for the following structural formula: CH3CH2C(CH3)CHCH(CH3)2 ?

3,3,5-trimethylhexane

Which of the following compounds contains the fewest hydrogen atoms?

Propyne

Which suffix is commonly used to indicate the presence of a ketone functional group?

-one

A molecule has the formula C2H6O. Which of the following functional groups could it contain? I. Alcohol II. Ketone

I only (Alcohol)

Which of the following is the correct IUPAC name for the alkane whose longest chain has eight carbons with methyl groups at C-2 and C-3 and an ethyl group at C-4?

4-ethyl-2,3-dimethyloctane

Which of the following is NOT a valid representation of 3-methyl-1-butene?

CH3-CH=CH-CH2-CH3

What is the molecular formula of 3-methyl-1-butene?

C5H10

How many constitutional isomers are possible for the molecular formula C5H12?

How many distinct branched constitutional isomers exist for the formula C4H10?

Which of the following statements about covalent bonding is true?

A σ bond has cylindrical symmetry about the bonding axis.

Which types of bonds are formed by a carbon atom with sp hybridization?

Two π bonds and two σ bonds.

What is the bond angle and molecular geometry around each carbon atom in ethene (CH2=CH2)?

120°, trigonal planar.

What is the hybridization of the oxygen atom in methanol (CH3OH)?

sp3

Which of the following types of covalent bonds is generally the strongest?

σ bond

Which of the following is NOT chiral?

A molecule with a plane of symmetry

Which of the following statements is true for an optically active compound?

The molecular configuration is chiral.

Which of the following compounds can exist as cis and trans (geometric) isomers?

1-Chloropropene

Which of the following is a necessary feature for a compound to have enantiomers?

Neither a double bond nor a ring is necessary; the necessary feature is chirality (e.g., a stereogenic center or another element of asymmetry).

A racemic mixture consists of equal amounts of:

Enantiomers

Which of the following is NOT an addition reaction?

Dehydration

In which type of reaction does one sigma bond break and another form at the same carbon atom?

Substitution

Which of the following best describes an electrophile?

An electron-deficient species that accepts electron pairs

Which of the following is a nucleophile?

CH3− (methyl anion)

Which of the following statements is FALSE?

A nucleophile must always be negatively charged.

Liquefied petroleum gas (LPG) is mainly composed of which pair of hydrocarbons?

Propane and Butane

Which of the following hydrocarbons has the lowest boiling point?

CH4 (methane)

Compared to ionic compounds of similar molar mass, hydrocarbons typically have:

Neither higher water solubility nor higher melting points (Neither I nor II)

What are the products of the complete combustion of an alkane?

CO2 and H2O

Alkanes undergo halogenation primarily through which mechanism?

Free radical substitution

Alkenes and alkynes, because they contain π bonds, typically undergo which type of reaction?

Electrophilic addition

Which of the following reactions can reduce an alkene to form an alkane?

Hydrogenation

What is the major product of the addition of Cl2 to 1-butene?

1,2-Dichlorobutane (CH2Cl-CHCl-CH2-CH3)

Which of the following reagent systems will convert an alkene to a bromohydrin (adds Br and OH across the double bond)?

Br2, H2O

All of the following reactions convert alkenes to alcohols except:

Ozonolysis

Which of the following statements about Markovnikov's rule is true?

The electrophile (e.g., H+) adds to the carbon with more hydrogens

Propene is treated with cold, dilute KMnO4 (syn dihydroxylation). What is the major product?

1,2-Propanediol (propane-1,2-diol)

In an alkene, the π bond is primarily responsible for which property?

Reactivity with electrophiles

Which of the following demonstrates anti-Markovnikov hydration of an alkene?

Hydroboration–oxidation of alkenes

Which of the following alkynes is a terminal alkyne?

CH≡C–CH2–CH3 (1-butyne)

What is the position of the bromine atom relative to the methyl group in 3-bromotoluene?