Industrial Chemistry MCQs with Answers
Which component in a dye is primarily responsible for its ability to bind to a fabric?
The chromophore group
The auxochrome group
The solvent medium
The quinoid ring structure
Bismarck Brown, used for dyeing wool and in boot polishes, belongs to which class of dyes based on its structure?
Triarylmethane Dyes
Nitro Dyes
Indigo Dyes
Azo Dyes
What is the color of the indicator phenolphthalein in a basic medium?
Vat dyes, such as Indigo, are applied to fabric in a special way. What is the key first step in the vat dyeing process?
Oxidizing the dye into a soluble, colored form.
Treating the fabric first with a metallic salt.
Reducing the dye into a soluble, colorless form.
Synthesizing the dye directly within the fabric fibers.
Malachite Green is an example of a triarylmethane dye. What is the characteristic structural feature of this class?
A central carbon bonded to three aromatic rings.
Two azo groups linking multiple aromatic rings.
A core structure of anthraquinone.
A nitroso group on a naphthalene ring system.
Which type of dye is applied to a fabric with the help of salts of aluminum or chromium, which form an insoluble complex?
Direct Dyes
Disperse Dyes
Vat Dyes
Mordant Dyes
Congo Red is prepared by coupling tetrazotised benzidine with two molecules of which compound?
Phenol
Naphthionic acid
Sulphanilic acid
m-diaminobenzene
Azoic dyeing, also known as ingrain dyeing, is a method that involves:
Applying the dye after a chemical reduction process.
Using a metallic salt to bind the dye to the fabric.
Producing an insoluble azo dye within the fabric itself.
Immersing the fabric in a colloidal form of the dye.
Which of the following is an example of a Nitro dye, containing the -NO₂ group as a chromophore?
Alizarin
Indigo
Methyl Orange
Naphthol Yellow S
The primary chromophore in azo dyes is the:
-N=N- group
-NO₂ group
Carbonyl group (>C=O)
Quinoid structure
The polymerization of ethylene to form polyethylene is an example of what type of polymerization?
Condensation polymerization
Addition polymerization
Copolymerization
Step-growth polymerization
What is the defining characteristic of a condensation polymer?
Formation from monomers containing double bonds.
Formation with the elimination of a small molecule.
The repeating unit and monomer have the same formula.
The product is always a thermoplastic polymer.
Nylon-6,6 is a polyamide formed by the condensation reaction between which two monomers?
Adipic acid and Hexamethylene diamine
Ethylene glycol and Terephthalic acid
Vinyl chloride and Vinyl acetate
Phenol and Formaldehyde
Which of the following is a key characteristic of a thermosetting polymer?
It softens upon heating and can be remolded.
It is made exclusively by addition polymerization.
It hardens upon heating and cannot be softened.
It has weak forces between its polymer chains.
Polyvinyl chloride (PVC) is an addition polymer formed from the monomer vinyl chloride, which is synthesized from acetylene and HCl.
1,2-dichloroethane
Chloroethene
Trichloroethene
Chloromethane
The reaction by which monomers are converted into polymers is known as:
Hydrolysis
Esterification
Polymerization
Isomerization
A polymer synthesized from more than one kind of monomer is called a:
Homopolymer
Copolymer
Thermoset
Addition polymer
During the addition polymerization of an alkene monomer, what happens to its double bond?
It stays unchanged within the polymer backbone.
Its pi bond breaks to form new sigma bonds.
It is eliminated from the chain as a small molecule.
It migrates to the terminal end of the polymer.
Which of the following is a common use for PVC?
Stockings and apparel
Packing materials and cable insulation
Imitation leather and corrugated roofing
Fishing lines and brush bristles
A polymer that softens on heating and becomes hard again on cooling is known as:
A thermosetting polymer
A thermoplastic polymer
An elastomer
A homopolymer
Adhesives that are made from sources like vegetable matter, starch, or animal skin are classified as:
Synthetic adhesives
Thermosetting adhesives
Natural adhesives
Contact adhesives
How do drying adhesives, such as white glue and rubber cement, harden?
By a chemical reaction between two components.
By cooling down from a molten state.
By the evaporation of their solvent.
By exposure to ultraviolet (UV) light.
What is the key application requirement for contact adhesives?
They must be applied while hot.
They must be mixed just before use.
They must be applied to both surfaces and dried before joining.
They only need to be applied to a single surface.
Hot glue, which is applied with a glue gun, is an example of which type of adhesive?
A natural bioadhesive
A drying adhesive
A thermoplastic adhesive
A UV curing adhesive
Elastomers, thermoplastics, and thermosetting adhesives are all examples of what broad category of adhesives?
Natural adhesives
Synthetic adhesives
Drying adhesives
Hot melt adhesives
UV and light curing adhesives are composed of low or medium molecular weight:
Resins
Starches
Solvents
Elastomers
What is the primary function of an adhesive?
To dissolve the surfaces of two items.
To act as a lubricant between two items.
To adhere or bond two items together.
To provide a decorative coating.
An example of a natural adhesive derived from starch is:
Epoxy
Dextrin
Super glue (cyanoacrylate)
Rubber cement
Which type of adhesive is popular for crafts due to its ease of use with a wide range of materials?
UV curing adhesives
Natural bioadhesives
Hot melt adhesives
Two-part epoxies
The term 'bioadhesives' often refers to which category of adhesives?
Synthetic adhesives
Hot melt adhesives
Natural adhesives
Drying adhesives
The preparation of Methyl Orange involves diazotising which compound first?
Dimethylaniline
Sulphanilic acid
p-nitroaniline
Benzidine
Which of the following dyes is also well-known as an acid-base indicator?
Malachite Green
Indigo
Phenolphthalein
Alizarin
Disperse dyes are primarily used for which type of fabric?
Natural fibers like wool and silk.
Cellulosic fibers like cotton.
Modern synthetic fabrics like nylon and polyester.
All types of fabrics equally.
The para quinoid structure is the characteristic chromophore in which class of dyes?
Azo Dyes
Nitro Dyes
Anthraquinone Dyes
Indigo Dyes
What is the function of an auxochrome like -OH or -NH₂ in a dye molecule?
To act as the primary chromophore for color.
To increase solubility and help bind the dye.
To decrease solubility for wash resistance.
To cause the dye molecules to polymerize.
Which of the following is NOT a characteristic of an addition polymer?
The monomer units contain double or triple bonds.
No molecule is eliminated during polymerization.
The polymer is formed in a step-wise manner.
The polymer's backbone consists of carbon atoms.
The monomers adipic acid and hexamethylene diamine each contain how many carbon atoms?
Both contain 6 carbon atoms.
Adipic acid has 6, hexamethylene diamine has 2.
Both contain 2 carbon atoms.
Adipic acid has 2, hexamethylene diamine has 6.
What type of chemical bond is formed between the monomers in Nylon-6,6?
Ester bond
Ether bond
Amide bond
Carbon-carbon single bond
A polymer made from a single type of monomer, such as polyethylene from ethylene, is called a:
Condensation polymer
Copolymer
Homopolymer
Thermoplastic
The synthesis of vinyl chloride monomer can be achieved by reacting acetylene with which substance in the presence of HgCl₂?
Which of these is NOT a typical use for Nylon-6,6?
Fibers for clothing and carpeting
Filaments for fishing lines and ropes
Molded objects like gears and bearings
Floor covering and gramophone records
The primary difference between a thermoplastic and a thermosetting polymer lies in their:
Monomer composition
Molecular weight
Behavior when heated
Solubility in water
Addition polymerization is also known as:
Step-growth polymerization
Chain-growth polymerization
Copolymerization
Ionic polymerization
Condensation polymerization is also known as:
Step-growth polymerization
Chain-growth polymerization
Radical polymerization
Homopolymerization
Which of these adhesive types works by a physical process rather than a chemical one?
Two-part epoxy
UV curing adhesive
Hot melt adhesive
Cyanoacrylate (Super Glue)
Which category of adhesives requires application to both surfaces before they are joined?
Drying adhesives
Contact adhesives
Hot glue adhesives
Natural adhesives
An adhesive made from inorganic mineral sources would be classified as:
Synthetic
Natural
Thermoplastic
Thermosetting
White glue, a common household and school adhesive, belongs to which class?
Hot melt adhesive
Contact adhesive
Drying adhesive
UV curing adhesive
What is a major advantage of modern synthetic adhesives over many traditional natural adhesives?
They are always less expensive.
They are more biodegradable.
They offer extremely high bond strength.
They are completely non-toxic.
The process of using a glue gun involves which type of adhesive?
Applying a drying adhesive
Melting and applying a hot melt adhesive
Mixing a two-part thermosetting adhesive
Applying a contact adhesive
Mordant Green 4 is a dye that contains which chromophore?
Azo group (-N=N-)
Nitroso group (-N=O)
Nitro group (-NO₂)
Quinoid ring
Para Red was the first azo dye prepared. Its synthesis involves the reaction of diazotized p-nitroaniline with what coupling compound?
Phenol
Aniline
β-naphthol
Dimethylaniline
The color of Methyl Orange changes from yellow in base to red in acid due to:
a hydration reaction.
a change in ionic structure.
the breakdown of the azo bond.
the removal of the sulfonate group.
What happens to the colorless, soluble form of Indigo ('Indigo White') when the dyed cloth is hung in the air?
It is reduced back to the insoluble dye.
It polymerizes on the fabric surface.
It is oxidized back to the insoluble, blue dye.
It reacts with a mordant in the fabric.
The synthesis of phenolphthalein involves heating phthalic anhydride with two moles of what substance?
Aniline
Phenol
Benzene
Benzoic acid
Direct dyes, like Martius Yellow, can be applied directly to fibers like wool and silk because:
they are insoluble and get trapped in the fibers.
they undergo a reduction-oxidation cycle.
their auxochromes interact with polar groups in the fiber.
they are chemically synthesized within the fiber itself.
Which of the following is NOT a main type of dye when classified by structure according to the provided text?
Azo Dyes
Anthraquinone Dyes
Indigo Dyes
Vat Dyes
The chemical stability of a dye, meaning it won't wash out with soap or fade in sunlight, is referred to as its:
Affinity
Fastness
Solubility
Chromogenicity
The structure of Alizarin is based on which parent aromatic hydrocarbon?
Naphthalene
Benzene
Anthracene
Phenanthrene
The 'lake' formed during mordant dyeing is:
a solution of the dye in water.
the reduced, colorless form of the dye.
an insoluble complex of fiber, mordant, and dye.
a colloidal dispersion of the dye.
What is the fundamental difference between homopolymers and copolymers?
The reaction type used for polymerization.
Their thermal behavior when heated.
The number of different monomers used.
Their final average molecular weight.
The process of forming polyethylene can be catalyzed by Ziegler catalysts, which consist of trialkyl aluminum and what other compound?
Titanium tetrachloride
Sulfuric acid
Mercury(II) chloride
An organic peroxide
In the abbreviated formula for an addition polymer like polyethylene, -[CH₂-CH₂]-n, what does the 'n' represent?
The number of carbons in the monomer.
The number of chains in the sample.
The number of repeating monomer units.
The number of branches on the chain.
Which of these is NOT a condensation polymer?
Nylon-6,6
Polyethylene terephthalate (a polyester)
Polyvinyl chloride (PVC)
Bakelite (phenol-formaldehyde resin)
The key difference in the final structure of thermosetting polymers compared to thermoplastic polymers is the presence of:
Repeating amide linkages.
Extensive cross-links.
Aromatic rings in the backbone.
Weak intermolecular forces.
To create a thermosetting polymer, it is beneficial to use:
a monomer with two functional groups.
a monomer with three or more functional groups.
a monomer with a carbon-carbon double bond.
a pre-formed linear polymer.
What is the structural formula of adipic acid, a monomer of Nylon-6,6?
HOOC-(CH₂)₄-COOH
H₂N-(CH₂)₆-NH₂
HOOC-COOH
CH₂=CH-COOH
What is the structural formula of hexamethylene diamine, a monomer of Nylon-6,6?
HOOC-(CH₂)₄-COOH
H₂N-(CH₂)₆-NH₂
H₂N-(CH₂)₂-NH₂
C₆H₅-NH₂
The repeating unit in polyethylene is:
-CH₂-
-(CH₂-CH₂)-
-(CH₂-CHCl)-
-(CH₃-CH₃)-
The repeating unit in polyvinyl chloride is:
-(CH₂-CH₂)-
-(CH₂-CHCl)-
-(CHCl-CHCl)-
-(CCl₂-CH₂)-
An adhesive that is a thermoplastic applied in a molten state is known as a:
Drying adhesive
Contact adhesive
Hot melt adhesive
Natural adhesive
Which of the following is an example of a synthetic adhesive?
Starch-based glue
Animal hide glue
Dextrin
Elastomer-based adhesive
The hardening of rubber cement is an example of which process?
Cooling of a thermoplastic
Curing via a chemical reaction
Evaporation of a solvent
Polymerization initiated by light
Which of these is NOT listed as a category of synthetic adhesives?
Elastomers
Thermoplastic adhesives
Thermosetting adhesives
Bioadhesives
What is the key functional group that gives an auxochrome its ability to bind to a protein fiber like wool?
A long hydrocarbon chain
An acidic or basic group
A carbon-carbon double bond
A central metal atom
The reaction to form Nylon-6,6 eliminates a small molecule. What is this molecule?
Ammonia (NH₃)
Hydrogen gas (H₂)
Water (H₂O)
Methanol (CH₃OH)
If you mix two different types of monomers, one with two acid groups and one with two alcohol groups, what type of polymer will you form?
A polyamide copolymer
A polyester copolymer
An addition homopolymer
A polyethylene copolymer
The main purpose of a mordant in dyeing is to:
Dissolve the dye so it can penetrate the fabric.
Act as a bridge to bind the dye to the fabric.
Reduce the dye to a colorless form.
Intensify the color of the chromophore.
Other Chemistry Topics MCQs
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