1. Nomenclature and Structure of Alkanoates
Q1. Alkanoates are functional isomers of which of the following homologous series?
- A. Alkanols
- B. Alkanoic acids
- C. Alkanals
- D. Alkanones
Answer: B. Alkanoic acids
Q2. What is the general molecular formula for acyclic saturated alkanoates?
- A. CnH2n+1CHO
- B. CnH2nO
- C. CnH2nO2
- D. CnH2n+2O
Answer: C. CnH2nO2
Q3. The functional group present in all alkanoates is represented structurally as
- A. —OH
- B. —CHO
- C. —COOH
- D. —COOR
Answer: D. —COOR
Q4. What is the IUPAC name of the compound CH3CH2COOCH3?
- A. Methyl propanoate
- B. Ethyl ethanoate
- C. Propyl methanoate
- D. Methyl ethanoate
Answer: A. Methyl propanoate
Q5. In the IUPAC nomenclature of alkanoates, the alkyl group attached directly to the oxygen atom is derived from the parent
- A. Alkanoic acid
- B. Alkanol
- C. Alkane
- D. Alkanal
Answer: B. Alkanol
Q6. Which of the following structural formulas represents ethyl methanoate?
- A. CH3COOCH3
- B. HCOOCH2CH3
- C. CH3COOCH2CH3
- D. HCOOCH3
Answer: B. HCOOCH2CH3
Q7. The physical property responsible for the characteristic pleasant fragrance of fruits like bananas and pineapples is due to the presence of
- A. Alkanols
- B. Alkanoic acids
- C. Alkanoates
- D. Alkanes
Answer: C. Alkanoates
Q8. What is the correct IUPAC name for the ester formed by the reaction between methanol and ethanoic acid?
- A. Ethyl methanoate
- B. Methyl ethanoate
- C. Ethanyl methanoate
- D. Methyl methanoate
Answer: B. Methyl ethanoate
Q9. Which structural feature describes the carbonyl carbon atom in an alkanoate functional group?
- A. It is sp3 hybridized and bound to two oxygen atoms
- B. It is sp2 hybridized and bound to two oxygen atoms
- C. It is sp hybridized and bound to one oxygen atom
- D. It forms only sigma bonds with surrounding atoms
Answer: B. It is sp2 hybridized and bound to two oxygen atoms
Q10. What is the clean structural arrangement for propyl ethanoate?
- A. CH3COOCH2CH2CH3
- B. CH3CH2COOCH2CH3
- C. CH3CH2CH2COOCH3
- D. HCOOCH2CH2CH3
Answer: A. CH3COOCH2CH2CH3
Q11. Compared to alkanoic acids of comparable molecular mass, alkanoates have lower boiling points because they
- A. Are highly volatile liquids
- B. Do not form intermolecular hydrogen bonds
- C. Contain fewer carbon atoms
- D. Are insoluble in organic solvents
Answer: B. Do not form intermolecular hydrogen bonds
Q12. What is the IUPAC name of the structure HCOOCH3?
- A. Methyl ethanoate
- B. Ethyl methanoate
- C. Methyl methanoate
- D. Formyl methanoate
Answer: C. Methyl methanoate
2. Preparation (Esterification)
Q1. Esterification is a reaction between an alkanol and an alkanoic acid to produce an alkanoate and
- A. Hydrogen gas
- B. Carbon(IV) oxide
- C. Water
- D. Water gas
Answer: C. Water
Q2. Which of the following catalysts is commonly employed during laboratory esterification reactions?
- A. Concentrated H2SO4
- B. Dilute HCl
- C. Finely divided iron
- D. Manganese(IV) oxide
Answer: A. Concentrated H2SO4
Q3. In an esterification setup, the role of concentrated tetraoxosulfate(VI) acid includes acting as a catalyst and a/an
- A. Oxidizing agent
- B. Reducing agent
- C. Dehydrating agent
- D. Drying agent
Answer: C. Dehydrating agent
Q4. Esterification is best described as what type of chemical reaction?
- A. Irreversible addition reaction
- B. Reversible condensation reaction
- C. Reversible substitution reaction
- D. Neutralization reaction
Answer: B. Reversible condensation reaction
Q5. During esterification, isotopic labeling experiments show that the water molecule formed receives its hydroxyl (—OH) group from the
- A. Alkanol
- B. Alkanoic acid
- C. Catalyst
- D. Solvent
Answer: B. Alkanoic acid
Q6. To shift the equilibrium position of an esterification reaction to favor a higher yield of ester, one can
- A. Add more water to the mixture
- B. Remove the ester or water as it forms
- C. Decrease the concentration of the alkanol
- D. Use dilute acid instead of concentrated acid
Answer: B. Remove the ester or water as it forms
Q7. When a mixture of ethanol, ethanoic acid, and concentrated H2SO4 is heated, how is the ester safely separated from the unreacted reagents?
- A. By adding sodium carbonate solution and separating the upper oily layer
- B. By direct filtration using filter paper
- C. By simple evaporation to dryness
- D. By adding water and collecting the precipitate
Answer: A. By adding sodium carbonate solution and separating the upper oily layer
Q8. What is the role of adding sodium carbonate (Na2CO3) solution during the isolation of an ester product?
- A. To dry the ester layer
- B. To neutralize unreacted alkanoic acid and catalyst
- C. To hydrolyze excess alkanol
- D. To catalyze the forward reaction
Answer: B. To neutralize unreacted alkanoic acid and catalyst
Q9. Which of the following pairs of reactants will produce butyl methanoate?
- A. Butanoic acid and methanol
- B. Methanoic acid and butanol
- C. Butanoic acid and ethanol
- D. Methanoic acid and propanol
Answer: B. Methanoic acid and butanol
Q10. The heating arrangement typically used during laboratory esterification is
- A. Direct heating over a Bunsen burner flame
- B. Heating in a water bath or reflux setup
- C. Heating inside a combustion furnace
- D. Leaving the mixture at room temperature without heat
Answer: B. Heating in a water bath or reflux setup
Q11. Why is direct heating over an open flame avoided during esterification experiments?
- A. The reaction is highly explosive
- B. The reactants and products are highly flammable organic compounds
- C. The catalyst breaks down into harmful gases
- D. Direct heat neutralizes the functional groups
Answer: B. The reactants and products are highly flammable organic compounds
Q12. Complete the reaction equation: CH3CH2COOH + CH3OH → [?] + H2O
- A. CH3COOCH2CH3
- B. CH3CH2COOCH3
- C. HCOOCH2CH2CH3
- D. CH3COOCH3
Answer: B. CH3CH2COOCH3
3. Saponification (Soap Making)
Q1. Saponification is defined chemically as the
- A. Acid hydrolysis of long-chain alkanoates
- B. Alkaline hydrolysis of fats and oils
- C. Esterification of glycerol and fatty acids
- D. Hydrogenation of unsaturated vegetable oils
Answer: B. Alkaline hydrolysis of fats and oils
Q2. The main organic raw materials used for the local manufacture of soap are
- A. Alkanols and alkanoic acids
- B. Fats/oils and strong alkalis
- C. Kerosene and sodium hydroxide
- D. Plastics and concentrated acids
Answer: B. Fats/oils and strong alkalis
Q3. Which of the following chemical substances is a valuable side-product obtained during saponification?
- A. Ethanol
- B. Propane-1,2,3-triol (Glycerol)
- C. Ethyl ethanoate
- D. Sodium chloride
Answer: B. Propane-1,2,3-triol (Glycerol)
Q4. In the commercial production of soap, concentrated sodium chloride (NaCl) is added to the boiled mixture to
- A. Purify the glycerol side-product
- B. Precipitate or separate the soap from the solution
- C. Neutralize excess alkali remaining in the mixture
- D. Give the soap its hard crystalline texture
Answer: B. Precipitate or separate the soap from the solution
Q5. The process of separating soap from the reaction mixture by adding common salt is technically termed
- A. Saponification
- B. Salting-out
- C. Neutralization
- D. Fractional distillation
Answer: B. Salting-out
Q6. Which alkali is used to produce soft soaps, such as liquid hand soaps and shaving creams?
- A. Sodium hydroxide (NaOH)
- B. Potassium hydroxide (KOH)
- C. Calcium hydroxide (Ca(OH)2)
- D. Ammonium hydroxide (NH4OH)
Answer: B. Potassium hydroxide (KOH)
Q7. Chemically, ordinary laundry soap can be classified as a sodium or potassium salt of
- A. Mineral acids
- B. Long-chain alkanoic (fatty) acids
- C. Complex sulfonic acids
- D. Substituted alkanols
Answer: B. Long-chain alkanoic (fatty) acids
Q8. Palm oil consists primarily of glyceryl esters of long-chain organic acids. Hydrolysis of palm oil using NaOH yields
- A. Sodium palmitate and glycerol
- B. Ethyl palmitate and water
- C. Methyl stearate and sodium chloride
- D. Palm oil distillate and hydrogen gas
Answer: A. Sodium palmitate and glycerol
Q9. Local soap makers in rural communities sometimes use ash from burnt plants as a raw material because the ash contains
- A. Sodium chloride
- B. Soluble alkaline carbonates like K2CO3
- C. Concentrated mineral acids
- D. Natural fats and oils
Answer: B. Soluble alkaline carbonates like K2CO3
Q10. What type of molecular structure enables a soap molecule to clean dirty surfaces?
- A. A completely hydrophobic structure
- B. A non-polar head and a polar tail
- C. A polar hydrophilic head and a non-polar hydrophobic tail
- D. A fully cyclic hydrocarbon backbone
Answer: C. A polar hydrophilic head and a non-polar hydrophobic tail
Q11. Fats and oils are structurally defined as triesters of which structural backbones?
- A. Methanol
- B. Glycerol
- C. Ethanol
- D. Glycol
Answer: B. Glycerol
Q12. What chemical hazard is managed by ensuring all alkali is completely consumed or neutralized at the end of saponification?
- A. The soap turning rancid and smelly
- B. Skin irritation or burning due to high alkalinity
- C. Excess lathering making the soap dissolve too quickly
- D. The soap turning into a gaseous state
Answer: B. Skin irritation or burning due to high alkalinity
4. Detergents (Saponifiable vs Non-saponifiable, Hard vs Soft Water Action)
Q1. What is the fundamental chemical difference between soapy and soapless detergents?
- A. Soapy detergents are synthetic while soapless detergents are fully natural
- B. Soapy detergents are sodium salts of fatty acids, while soapless detergents are typically sodium salts of long-chain alkyl benzene sulfonates
- C. Soapless detergents contain no hydrophilic regions
- D. Soapy detergents are non-biodegradable while synthetic detergents decompose instantly
Answer: B. Soapy detergents are sodium salts of fatty acids, while soapless detergents are typically sodium salts of long-chain alkyl benzene sulfonates
Q2. Which of the following groups contains saponifiable matter?
- A. Petroleum fractions
- B. Vegetable oils and animal fats
- C. Synthetic paraffin waxes
- D. Heavy crude motor oils
Answer: B. Vegetable oils and animal fats
Q3. Non-saponifiable lipids or materials are substances that cannot be hydrolyzed by an alkali because they lack
- A. Carbon atoms
- B. Ester linkages
- C. Double bonds
- D. Methyl groups
Answer: B. Ester linkages
Q4. When ordinary soap is used in hard water, it forms an insoluble gray slime called scum. This scum is chemically composed of
- A. Sodium carbonate and magnesium sulfate
- B. Insoluble calcium and magnesium salts of fatty acids
- C. Soluble sodium tetraoxosulfate(VI)
- D. Lead and zinc oxides
Answer: B. Insoluble calcium and magnesium salts of fatty acids
Q5. Why do synthetic (soapless) detergents lather easily and clean effectively even in hard water?
- A. They react with hard water to form a soft oily layer
- B. Their corresponding calcium and magnesium salts are highly soluble in water
- C. They alter the chemical nature of hard water to make it soft instantly
- D. They contain no hydrophilic components
Answer: B. Their corresponding calcium and magnesium salts are highly soluble in water
Q6. Which of the following ion pairs are responsible for the hardness of water that hinders the action of ordinary soap?
- A. Na+ and K+
- B. Ca2+ and Mg2+
- C. Cu2+ and Fe3+
- D. Al3+ and NH4+
Answer: B. Ca2+ and Mg2+
Q7. An environmental disadvantage of using certain synthetic detergents over ordinary soapy detergents is that synthetic detergents
- A. Are highly expensive to store
- B. May contain branched hydrocarbon chains that are non-biodegradable, causing water pollution
- C. Do not lather well in river water
- D. Cause the immediate corrosion of plumbing pipes
Answer: B. May contain branched hydrocarbon chains that are non-biodegradable, causing water pollution
Q8. Soapless detergents with unbranched (straight-chain) hydrocarbons are preferred nowadays by environmentalists because they are
- A. Cheap to manufacture
- B. Biodegradable and can be broken down by bacteria
- C. Highly resistant to bacterial decomposition
- D. Insoluble in natural water bodies
Answer: B.
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