Q. Which of the following statements about optical isomers is true?
-
A.
They have the same physical properties
-
B.
They rotate plane-polarized light in opposite directions
-
C.
They have different molecular formulas
-
D.
They are always chiral
Solution
Optical isomers, or enantiomers, rotate plane-polarized light in opposite directions.
Correct Answer: B — They rotate plane-polarized light in opposite directions
Learn More →
Q. Which of the following statements about phenols is true?
-
A.
They are weak acids.
-
B.
They are strong bases.
-
C.
They do not react with bromine.
-
D.
They are insoluble in water.
Solution
Phenols are weak acids due to the ability of the hydroxyl group to donate a proton.
Correct Answer: A — They are weak acids.
Learn More →
Q. Which of the following statements is false regarding inductive effect?
-
A.
It is a permanent effect
-
B.
It decreases with distance
-
C.
It is stronger than mesomeric effect
-
D.
It can be +I or -I
Solution
The inductive effect is generally weaker than the mesomeric effect.
Correct Answer: C — It is stronger than mesomeric effect
Learn More →
Q. Which of the following statements is false regarding the inductive effect?
-
A.
It is a permanent effect.
-
B.
It operates through sigma bonds.
-
C.
It can be observed in both aliphatic and aromatic compounds.
-
D.
It involves the delocalization of pi electrons.
Solution
The inductive effect does not involve the delocalization of pi electrons; that is characteristic of the mesomeric effect.
Correct Answer: D — It involves the delocalization of pi electrons.
Learn More →
Q. Which of the following statements is true about aldehydes?
-
A.
They cannot form hydrogen bonds
-
B.
They are generally more reactive than ketones
-
C.
They have higher boiling points than ketones
-
D.
They are less soluble in water than ketones
Solution
Aldehydes are generally more reactive than ketones due to the presence of the hydrogen atom attached to the carbonyl carbon.
Correct Answer: B — They are generally more reactive than ketones
Learn More →
Q. Which of the following statements is true about alkynes?
-
A.
They are less reactive than alkenes.
-
B.
They are more acidic than alkenes.
-
C.
They cannot undergo addition reactions.
-
D.
They have a higher boiling point than alkenes.
Solution
Alkynes are more acidic than alkenes due to the sp hybridization of the carbon atoms.
Correct Answer: B — They are more acidic than alkenes.
Learn More →
Q. Which of the following statements is true about carboxylic acids?
-
A.
They are always soluble in water
-
B.
They have higher boiling points than alcohols
-
C.
They cannot form hydrogen bonds
-
D.
They are weak bases
Solution
Carboxylic acids have higher boiling points than alcohols due to the ability to form dimers through hydrogen bonding.
Correct Answer: B — They have higher boiling points than alcohols
Learn More →
Q. Which of the following statements is true about ethers?
-
A.
They are polar compounds
-
B.
They have high boiling points
-
C.
They are highly reactive
-
D.
They are used as solvents
Solution
Ethers are commonly used as solvents due to their relatively low reactivity and ability to dissolve a wide range of substances.
Correct Answer: D — They are used as solvents
Learn More →
Q. Which of the following statements is true about ketones?
-
A.
They can be oxidized to carboxylic acids
-
B.
They have a higher boiling point than aldehydes
-
C.
They cannot form hydrogen bonds
-
D.
They are more reactive than aldehydes
Solution
Ketones cannot form hydrogen bonds with themselves due to the absence of a hydrogen atom attached to the carbonyl carbon.
Correct Answer: C — They cannot form hydrogen bonds
Learn More →
Q. Which of the following statements is true regarding mesomeric effect?
-
A.
It is a permanent effect
-
B.
It is a temporary effect
-
C.
It only applies to alkenes
-
D.
It increases acidity
Solution
The mesomeric effect is a permanent effect due to the delocalization of electrons.
Correct Answer: A — It is a permanent effect
Learn More →
Q. Which of the following statements is true regarding optical isomers?
-
A.
They are superimposable
-
B.
They have identical physical properties
-
C.
They rotate plane-polarized light in opposite directions
-
D.
They have different molecular formulas
Solution
Optical isomers, or enantiomers, rotate plane-polarized light in opposite directions.
Correct Answer: C — They rotate plane-polarized light in opposite directions
Learn More →
Q. Which of the following statements is true regarding the -I effect?
-
A.
It stabilizes carbocations
-
B.
It destabilizes carbanions
-
C.
It withdraws electron density
-
D.
It donates electron density
Solution
-I effect withdraws electron density, which can destabilize carbocations and stabilize carbanions.
Correct Answer: C — It withdraws electron density
Learn More →
Q. Which of the following statements is true regarding the inductive effect?
-
A.
It is a temporary effect.
-
B.
It operates through pi bonds.
-
C.
It is stronger than the mesomeric effect.
-
D.
It decreases with distance.
Solution
The inductive effect decreases with distance from the electronegative atom or group.
Correct Answer: D — It decreases with distance.
Learn More →
Q. Which of the following statements is true regarding the mesomeric effect?
-
A.
It can only be observed in aliphatic compounds.
-
B.
It involves the movement of sigma electrons.
-
C.
It is responsible for the stability of resonance structures.
-
D.
It is a short-range effect.
Solution
The mesomeric effect is responsible for the stability of resonance structures due to the delocalization of pi electrons.
Correct Answer: C — It is responsible for the stability of resonance structures.
Learn More →
Q. Which of the following techniques is commonly used to determine protein structure?
-
A.
Mass spectrometry
-
B.
Nuclear magnetic resonance (NMR)
-
C.
X-ray crystallography
-
D.
Both B and C
Solution
Both nuclear magnetic resonance (NMR) and X-ray crystallography are commonly used techniques to determine the three-dimensional structure of proteins.
Correct Answer: D — Both B and C
Learn More →
Q. Which of the following techniques is commonly used to separate proteins based on their size?
-
A.
Chromatography
-
B.
Electrophoresis
-
C.
Spectroscopy
-
D.
Centrifugation
Solution
Gel electrophoresis is a technique used to separate proteins based on their size and charge.
Correct Answer: B — Electrophoresis
Learn More →
Q. Which polymer is commonly used in the production of plastic bottles?
-
A.
Polypropylene
-
B.
Polyethylene terephthalate
-
C.
Polystyrene
-
D.
Polyvinyl chloride
Solution
Polyethylene terephthalate (PET) is commonly used in the production of plastic bottles.
Correct Answer: B — Polyethylene terephthalate
Learn More →
Q. Which polymer is commonly used in the production of rubber?
-
A.
Polyethylene
-
B.
Natural rubber
-
C.
Polystyrene
-
D.
Polyvinyl chloride
Solution
Natural rubber is a polymer that is widely used in the production of rubber products.
Correct Answer: B — Natural rubber
Learn More →
Q. Which polymer is known for its high resistance to heat and chemicals?
-
A.
Polyethylene
-
B.
Teflon
-
C.
Nylon
-
D.
Acrylic
Solution
Teflon is known for its high resistance to heat and chemicals.
Correct Answer: B — Teflon
Learn More →
Q. Which property is NOT typical of elastomers?
-
A.
High elasticity
-
B.
Low tensile strength
-
C.
Good resilience
-
D.
Brittleness
Solution
Brittleness is not a typical property of elastomers; they are known for their high elasticity and resilience.
Correct Answer: D — Brittleness
Learn More →
Q. Which property of polymers is primarily affected by their molecular weight?
-
A.
Color
-
B.
Density
-
C.
Melting point
-
D.
Solubility
Solution
The melting point of polymers is primarily affected by their molecular weight; higher molecular weight generally leads to higher melting points.
Correct Answer: C — Melting point
Learn More →
Q. Which reaction involves the addition of water to an alkene?
-
A.
Hydrogenation
-
B.
Hydrolysis
-
C.
Hydration
-
D.
Dehydration
Solution
The addition of water to an alkene is called hydration.
Correct Answer: C — Hydration
Learn More →
Q. Which reaction is characteristic of alkenes?
-
A.
Hydrogenation
-
B.
Halogenation
-
C.
Hydrolysis
-
D.
Oxidation
Solution
Alkenes readily undergo halogenation due to the presence of a double bond.
Correct Answer: B — Halogenation
Learn More →
Q. Which reaction is characteristic of alkynes?
-
A.
Hydrogenation
-
B.
Halogenation
-
C.
Hydrohalogenation
-
D.
All of the above
Solution
Alkynes can undergo hydrogenation, halogenation, and hydrohalogenation.
Correct Answer: D — All of the above
Learn More →
Q. Which reaction is commonly used to convert alkynes to alkenes?
-
A.
Hydrogenation
-
B.
Halogenation
-
C.
Hydroboration
-
D.
Dehydrohalogenation
Solution
Hydrogenation is used to convert alkynes to alkenes.
Correct Answer: A — Hydrogenation
Learn More →
Q. Which reaction is used to convert alkenes to alkanes?
-
A.
Hydrogenation
-
B.
Halogenation
-
C.
Hydrolysis
-
D.
Dehydrogenation
Solution
Hydrogenation is the process of adding hydrogen to alkenes to convert them into alkanes.
Correct Answer: A — Hydrogenation
Learn More →
Q. Which reaction is used to prepare alkynes from alkenes?
-
A.
Hydrogenation
-
B.
Dehydrohalogenation
-
C.
Hydrohalogenation
-
D.
Halogenation
Solution
Dehydrohalogenation of vicinal dihalides can be used to prepare alkynes from alkenes.
Correct Answer: B — Dehydrohalogenation
Learn More →
Q. Which reagent can be used to convert a haloalkane into an alcohol?
-
A.
Sodium hydroxide
-
B.
Sodium chloride
-
C.
Sodium bromide
-
D.
Sodium acetate
Solution
Sodium hydroxide (NaOH) can be used to perform nucleophilic substitution, converting haloalkanes into alcohols.
Correct Answer: A — Sodium hydroxide
Learn More →
Q. Which reagent can be used to convert a haloalkane to an alcohol?
-
A.
Sodium hydroxide
-
B.
Sodium metal
-
C.
Hydrochloric acid
-
D.
Bromine
Solution
Sodium hydroxide can be used to convert haloalkanes to alcohols through nucleophilic substitution.
Correct Answer: A — Sodium hydroxide
Learn More →
Q. Which reagent can be used to convert an alkyne to a diketone?
-
A.
KMnO4
-
B.
O3
-
C.
H2O
-
D.
H2SO4
Solution
Ozonolysis of an alkyne can yield a diketone.
Correct Answer: B — O3
Learn More →
Showing 841 to 870 of 951 (32 Pages)