What is the key difference between wool and cotton fibers?
- Wool fibers are spirally twisted tubes
- Wool fibers contain sulphur
- Cotton fibers are made of cellulose
- Cotton fibers contain nitrogen
Correct Answer: Wool fibers contain sulphur
Correct Answer Explanation: Animal fibers like wool and fur contain sulfur, while plant fibers like cotton and flax do not. This difference is crucial in identifying the origin of a textile fiber.
What is the “carrotting” process used for?
- Softening wool fibers for felting
- Removing impurities from wool fibers
- Improving the dyeing properties of wool fibers
- Enhancing the felting properties of fur
Correct Answer: Enhancing the felting properties of fur
Correct Answer Explanation: The carrotting process involves treating fur with nitric acid and mercuric nitrate, which damages the fiber’s surface and increases its felting ability. However, this process can also be harmful to the environment and the health of workers.
What is the “veneering” process used for?
- Creating a smooth finish on hat brims
- Adding a layer of unproofed wool to a hat body
- Dyeing hats a more even and durable color
- Creating a waterproof coating on hats
Correct Answer: Adding a layer of unproofed wool to a hat body
Correct Answer Explanation: The veneering process, invented in 1887 by F.W. Cheetham, involves adding a layer of unproofed wool or fur to the surface of a proofed hat body. This helps create a more even and durable surface for dyeing, addressing a major challenge in the hat industry.
What is the detrimental effect of hard water on hat making?
- Hard water makes wool fibers more brittle
- Hard water makes dyes less effective
- Hard water increases the cost of dyeing
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: Hard water, containing dissolved minerals like calcium and magnesium, can negatively impact hat making in several ways:
- It wastes soap, as the minerals react with soap to form a precipitate.
- It interferes with the mordanting process, affecting the dye’s adherence to the fibers.
- It can damage dyes and make them less effective.
What is the role of mordants in dyeing?
- Mordants are used to soften fibers for dyeing
- Mordants are used to remove impurities from fibers
- Mordants are used to fix dyes to fabrics
- Mordants are used to create different colors
Correct Answer: Mordants are used to fix dyes to fabrics
Correct Answer Explanation: Mordants act as a bridge between the dye and the fabric, helping the dye adhere to the fibers more effectively and creating a more permanent color. Different mordants are used for different dyes and fabrics.
What is the main difference between substantive and adjective dyes?
- Substantive dyes are used for wool and adjective dyes are used for cotton
- Substantive dyes are water-soluble and adjective dyes are not
- Substantive dyes require a mordant and adjective dyes do not
- Substantive dyes dye directly and adjective dyes require a mordant
Correct Answer: Substantive dyes dye directly and adjective dyes require a mordant
Correct Answer Explanation: Substantive dyes, also known as direct dyes, have an affinity for the fabric and can dye it directly without a mordant. Adjective dyes, on the other hand, require a mordant to fix them to the fabric.
What is the significance of the “indigo-vat” method?
- It is a method for dyeing silk a vibrant blue
- It is a method for creating a waterproof finish on hats
- It is a method for dyeing cotton a deep indigo blue
- It is a method for creating a color fastness test
Correct Answer: It is a method for dyeing cotton a deep indigo blue
Correct Answer Explanation: The indigo-vat method involves reducing indigo blue to soluble indigo white, which can then dye fabrics. The indigo white then oxidizes back to insoluble indigo blue, fixing the dye to the fabric.
What is the main challenge of dyeing felt hats a deep black?
- Black dyes tend to fade quickly on felt
- Felt is highly porous and absorbs dye unevenly
- Felt is naturally resistant to black dyes
- Achieving a true black requires a mixture of dyes
Correct Answer: Achieving a true black requires a mixture of dyes
Correct Answer Explanation: Dyeing felt hats a true black is a complex process. A single black dye often doesn’t produce the desired shade, so a mixture of different dyes is needed to create a deep, rich black color.
What is the main reason for using soft water in hat making?
- Soft water helps to prevent fibers from shrinking
- Soft water improves the dyeing process and minimizes waste
- Soft water helps to prevent the build-up of impurities on the fibers
- Soft water makes the final hat product softer and more comfortable
Correct Answer: Soft water improves the dyeing process and minimizes waste
Correct Answer Explanation: Hard water, containing dissolved minerals, can interfere with the dyeing process, leading to uneven color and waste. Soft water, on the other hand, helps to improve the efficiency and effectiveness of dyeing.
What is a key component of the “yolk” or “suint” found in wool?
- Cholesterol
- Keratin
- Melanin
- Sericin
Correct Answer: Cholesterol
Correct Answer Explanation: The “yolk” or “suint” in wool contains a substance resembling a fat called cholesterol, which is of great therapeutical value. This highlights the potential for waste products from industry to have valuable applications.
What is the approximate yield of coal-tar from one ton of Lancashire coal?
- 12 gallons
- 12 pounds
- 12 liters
- 12 kilograms
Correct Answer: 12 gallons
Correct Answer Explanation: One ton of Lancashire coal yields about 12 gallons of coal-tar, which is a valuable source of various chemicals and dyes.
What is the main component of silk?
- Cellulose
- Fibroïn
- Keratin
- Sericin
Correct Answer: Fibroïn
Correct Answer Explanation: Fibroïn is the protein that makes up the core of the silk fiber, giving it its strength and luster. Sericin is the silk-glue that surrounds the fibroïn fiber, providing a protective coating.
What is the “silk-glue” or “silk-gum” called?
- Keratin
- Sericin
- Fibroïn
- Cellulose
Correct Answer: Sericin
Correct Answer Explanation: Sericin is the silk-glue or silk-gum that surrounds the fibroïn fiber. It is removed in the ungumming process, making the silk fibers more lustrous and easier to dye.
What is the approximate percentage of impurities found in raw cotton?
- 2%
- 5%
- 10%
- 15%
Correct Answer: 5%
Correct Answer Explanation: Raw cotton contains about 5% impurities, including seeds, leaves, and other debris. This highlights the importance of cleaning raw materials for better dyeing and processing.
What is the approximate range of length for cotton fibers?
- 0.5 to 1.5 centimeters
- 2.5 to 6 centimeters
- 10 to 20 centimeters
- 30 to 50 centimeters
Correct Answer: 2.5 to 6 centimeters
Correct Answer Explanation: Cotton fibers vary from 2.5 to 6 centimeters in length and 0.017 to 0.05 millimeters in breadth, giving a sense of the scale of cotton fibers.
What is the boiling point of water at sea level?
- 180°F (82°C)
- 200°F (93°C)
- 212°F (100°C)
- 220°F (104°C)
Correct Answer: 212°F (100°C)
Correct Answer Explanation: Water boils at 212°F (100°C) at sea level. This is a fundamental property of water.
What is the latent heat of water?
- 536 heat units
- 79 heat units
- 100 heat units
- 212 heat units
Correct Answer: 79 heat units
Correct Answer Explanation: The latent heat of water is 79 heat units, meaning that 79 units of heat are needed to melt 1 kilogram of ice. This is the amount of energy required to change the state of water from solid to liquid without changing its temperature.
What is the latent heat of steam?
- 79 heat units
- 100 heat units
- 212 heat units
- 536 heat units
Correct Answer: 536 heat units
Correct Answer Explanation: The latent heat of steam is 536 heat units, meaning that 536 units of heat are needed to convert 1 kilogram of water into steam. This is the amount of energy required to change the state of water from liquid to gas without changing its temperature.
What is the approximate monthly consumption of soap in London?
- 100,000 kilograms
- 500,000 kilograms
- 1,000,000 kilograms
- 5,000,000 kilograms
Correct Answer: 1,000,000 kilograms
Correct Answer Explanation: The monthly consumption of soap in London is 1,000,000 kilograms (about 1000 tons), highlighting the scale of soap consumption.
What is the approximate increase in soap consumption in London due to hard water?
- 23,000 kilograms
- 230,000 kilograms
- 2,300,000 kilograms
- 23,000,000 kilograms
Correct Answer: 230,000 kilograms
Correct Answer Explanation: The hardness of the Thames water means the use of 230,000 kilograms (nearly 230 tons) more soap per month than if soft water were used, demonstrating the significant impact of water hardness on soap consumption.
What is a key chemical element found in animal fibers like wool and fur?
- Carbon
- Nitrogen
- Oxygen
- Sulphur
Correct Answer: Sulphur
Correct Answer Explanation: Animal fibers like wool and fur contain sulfur, which can be detected using tests like the alkaline lead solution. This distinguishes them from vegetable fibers, which do not contain sulfur.
What is the chemical formula for water?
- H2O
- CO2
- N2O
- O2
Correct Answer: H2O
Correct Answer Explanation: Water is a compound of hydrogen and oxygen, with the chemical formula H2O. This simple formula represents the fundamental composition of water.
What is the main gas released when wool and fur decompose at high temperatures?
- Carbon dioxide
- Hydrogen sulfide
- Nitrogen dioxide
- Oxygen
Correct Answer: Hydrogen sulfide
Correct Answer Explanation: Wool and fur decompose when heated to a high temperature, releasing ammonia and sulfur-containing vapors, indicating the presence of nitrogen and sulfur in the fibers. This process can also release hydrogen sulfide, a gas with a characteristic rotten egg smell.
What is the approximate amount of benzene produced from 12 gallons of coal-tar?
- 1-1/10 lb.
- 9/10 lb.
- 1½ lb.
- 6½ lb.
Correct Answer: 1-1/10 lb.
Correct Answer Explanation: The 12 gallons of coal-tar yield 1-1/10 lb. of benzene, 9/10 lb. of toluene, 1½ lb. of carbolic acid, between 1/10 and 2/10 lb. of xylene, 6½ lb. of naphthalene, and ½ lb. of anthracene, showing the proportions of valuable products obtained from coal-tar.
What is the main chemical compound involved in the production of aniline?
- Nitrobenzene
- Benzene
- Toluene
- Xylene
Correct Answer: Nitrobenzene
Correct Answer Explanation: The production of aniline involves reducing nitrobenzene with hydrogen gas. Nitrobenzene is a key intermediate in the production of many dyes and other chemicals.
What is the approximate amount of Magenta needed to dye 500 yards of flannel a full shade?
- 0.25 lb.
- 0.623 lb.
- 1.25 lb.
- 2.5 lb.
Correct Answer: 0.623 lb.
Correct Answer Explanation: 0.623 lb. of Magenta will dye 500 yards of flannel, 27 inches wide, a full shade, demonstrating the impressive dyeing power of coal-tar dyes.
What is the approximate amount of Alizarin needed to dye 255 yards of Printers’ cloth a full Turkey red?
- 0.25 lb.
- 0.75 lb.
- 1.25 lb.
- 2.25 lb.
Correct Answer: 2.25 lb.
Correct Answer Explanation: 2.25 lb. of Alizarin (20%) will dye 255 yards of Printers’ cloth a full Turkey red, showing the dyeing power of Alizarin.
What is the approximate amount of a violet dye solution needed to dye a skein of silk a bright full shade of violet?
- One drop
- Two drops
- Five drops
- Ten drops
Correct Answer: Two drops
Correct Answer Explanation: Two drops of a violet dye solution can dye a skein of silk a bright full shade of violet, highlighting the intense tinctorial power of some coal-tar dyes.
What is the main reason for using a mixture of dyes to achieve a true black on felt?
- Different dyes have different affinities for felt fibers
- Different dyes have different color fastness properties
- Different dyes have different chemical properties
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: Dyeing felt hats a true black is a complex process. Different dyes have different affinities for felt fibers, color fastness properties, and chemical properties. Using a mixture of dyes helps to create a deeper, richer black shade that is more durable and less likely to fade.
What is the approximate percentage of precipitate that accumulates in logwood black dye baths?
- 5%
- 10%
- 25%
- 50%
Correct Answer: 25%
Correct Answer Explanation: The mud or precipitate that accumulates in logwood black dye baths amounts to no less than 25% of the weight of the copperas used, indicating the potential for waste and inefficiency in poorly-managed dye baths.
What is the name of the protein that makes up the core of a silk fiber?
- Cellulose
- Fibroïn
- Keratin
- Sericin
Correct Answer: Fibroïn
Correct Answer Explanation: Fibroïn is the protein that makes up the core of the silk fiber, giving it its strength and luster.
What is the approximate amount of moisture wool can absorb in damp conditions?
- 8 to 10%
- 15 to 20%
- 30 to 50%
- 60 to 80%
Correct Answer: 30 to 50%
Correct Answer Explanation: Wool can absorb from 8 to 10% moisture in dry weather and 30 to 50% in damp conditions, highlighting the importance of moisture testing when purchasing wool.
What is the main chemical involved in the production of nitrobenzene?
- Nitric acid
- Sulphuric acid
- Hydrochloric acid
- Acetic acid
Correct Answer: Nitric acid
Correct Answer Explanation: Nitrobenzene is produced by reacting benzene with nitric acid. This reaction is a key step in the production of many dyes and other chemicals.
What is the process called when a liquid changes into a vapor?
- Condensation
- Evaporation
- Ebullition
- Sublimation
Correct Answer: Ebullition
Correct Answer Explanation: Ebullition is the process of boiling, where a liquid changes into a vapor. This process occurs when the vapor pressure of the liquid equals the surrounding atmospheric pressure.
What is the name of the salt formed by the partial neutralization of an acid by a base?
- Acid salt
- Basic salt
- Neutral salt
- Double salt
Correct Answer: Acid salt
Correct Answer Explanation: An acid salt is a salt formed by the partial neutralization of an acid by a base. This means that the acid has not been completely neutralized, leaving some of its hydrogen ions still present in the salt.
What is the name of the salt formed by the partial neutralization of a base by an acid?
- Acid salt
- Basic salt
- Neutral salt
- Double salt
Correct Answer: Basic salt
Correct Answer Explanation: A basic salt is a salt formed by the partial neutralization of a base by an acid. This means that the base has not been completely neutralized, leaving some of its hydroxide ions still present in the salt.
What is the name of the test used to determine the percentage of silk in a mixed fabric?
- The carrotting test
- The veneering test
- The indigo-vat test
- The basic zinc chloride test
Correct Answer: The basic zinc chloride test
Correct Answer Explanation: Basic zinc chloride dissolves silk but not wool or vegetable fibers. This property is used in a method for determining the percentage of silk in a mixed fabric.
What is the main chemical compound that makes up cotton fibers?
- Fibroïn
- Keratin
- Cellulose
- Sericin
Correct Answer: Cellulose
Correct Answer Explanation: Cellulose is a complex carbohydrate found in plants and is the main component of cotton fibers. This makes cotton a vegetable fiber, as opposed to animal fibers like wool and silk.
What is the chemical process involved in reducing indigo blue to soluble indigo white?
- Oxidation
- Reduction
- Hydrolysis
- Condensation
Correct Answer: Reduction
Correct Answer Explanation: The indigo-vat method involves reducing indigo blue to soluble indigo white through a process called reduction. This process involves the addition of electrons to the indigo molecule, changing its chemical structure and making it soluble in water.
What is the name of the complex carbohydrate found in plants that makes up the main component of cotton, flax, and other vegetable fibers?
- Fibroïn
- Keratin
- Cellulose
- Sericin
Correct Answer: Cellulose
Correct Answer Explanation: Cellulose is a complex carbohydrate found in plants, forming the main component of cotton, flax, and other vegetable fibers. It gives these fibers their strength and durability.
What is the name of the test used to determine the presence of sulphur in wool, fur, and hair?
- The basic zinc chloride test
- The indigo-vat test
- The sulphuretted hydrogen test
- The carrotting test
Correct Answer: The sulphuretted hydrogen test
Correct Answer Explanation: Sulphuretted hydrogen (H2S) is a good test for sulphur in wool, fur, and hair. When sulphuretted hydrogen gas is passed over a lead acetate solution, it forms a black sulfide of lead, indicating the presence of sulphur.
What is the name of the chemical process involved in converting nitrobenzene to aniline?
- Oxidation
- Reduction
- Hydrolysis
- Condensation
Correct Answer: Reduction
Correct Answer Explanation: The conversion of nitrobenzene to aniline involves a process called reduction, which involves the addition of hydrogen atoms to the nitrobenzene molecule. This process changes the chemical structure of the molecule and produces aniline.
What is the name of the process involved in removing the “silk-glue” or “silk-gum” from silk fibers?
- Carrotting
- Veneering
- Ungumming
- Proofing
Correct Answer: Ungumming
Correct Answer Explanation: The ungumming process involves removing the silk-glue or silk-gum (sericin) from silk fibers. This process makes the silk fibers more lustrous and easier to dye.
What is the name of the substance used to fix a dye to a fabric?
- Pigment
- Mordant
- Dye
- Binder
Correct Answer: Mordant
Correct Answer Explanation: A mordant is a substance used to fix a dye to a fabric. It acts as a bridge between the dye and the fabric, helping the dye adhere more effectively and creating a more permanent color. Different mordants are used for different dyes and fabrics.
What is the main reason why a single black dye often doesn’t produce the desired shade on felt hats?
- Felt is highly porous and absorbs dye unevenly
- Felt is naturally resistant to black dyes
- Black dyes tend to fade quickly on felt
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: Dyeing felt hats a true black is a complex process. Felt is highly porous and absorbs dye unevenly, making it difficult to achieve a consistent color. Felt is also naturally resistant to some black dyes, and black dyes tend to fade quickly on felt. This is why a mixture of dyes is often needed to create a deep, rich black shade that is more durable and less likely to fade.
What is the name of the process involved in adding a layer of unproofed wool or fur to the surface of a proofed hat body?
- Carrotting
- Veneering
- Ungumming
- Proofing
Correct Answer: Veneering
Correct Answer Explanation: The veneering process involves adding a layer of unproofed wool or fur to the surface of a proofed hat body. This helps create a more even and durable surface for dyeing, addressing a major challenge in the hat industry.
What is the name of the process involved in treating fur with nitric acid and mercuric nitrate to enhance its felting properties?
- Carrotting
- Veneering
- Ungumming
- Proofing
Correct Answer: Carrotting
Correct Answer Explanation: The carrotting process involves treating fur with nitric acid and mercuric nitrate, which damages the fiber’s surface and increases its felting ability. However, this process can also be harmful to the environment and the health of workers.