What type of glue is typically produced from calves’ heads?
- Animal glue
- Fish glue
- Vegetable glue
- Synthetic glue
Correct Answer: Animal glue
Correct Answer Explanation: Calves’ heads are highly valued for producing animal glue, especially for gelatine, because they yield a superior quality due to their purity.
Which of these materials is NOT a primary source of glue?
- Animal skins
- Fish bladders
- Cotton fibers
- Bones
Correct Answer: Cotton fibers
Correct Answer Explanation: Cotton fibers are not used in the production of glue. Glue is typically derived from animal sources, such as skins, bones, and fish bladders.
What is the primary component of glue that gives it its adhesive properties?
- Chondrin
- Ossein
- Collagen
- Glutin
Correct Answer: Glutin
Correct Answer Explanation: Glutin is a protein found in animal tissues and is the main component of glue. It gives glue its strong adhesive properties.
What is the main difference between glue and gelatine?
- Glue is derived from animal bones, while gelatine is derived from animal skins.
- Glue is used for construction purposes, while gelatine is used in food and medicine.
- Glue is typically opaque, while gelatine is typically translucent.
- Glue is produced through a dry process, while gelatine is produced through a wet process.
Correct Answer: Glue is typically opaque, while gelatine is typically translucent.
Correct Answer Explanation: Glue is typically opaque, often appearing brown or yellowish, while gelatine is typically translucent and often colorless. This difference is due to the specific processing methods and the different raw materials used.
How is animal charcoal produced?
- By burning bones in an open fire.
- By boiling bones in water.
- By calcining bones in airtight vessels.
- By extracting bones with hydrochloric acid.
Correct Answer: By calcining bones in airtight vessels.
Correct Answer Explanation: Animal charcoal is produced by calcining bones in airtight vessels, a process that converts the glue-yielding tissue into carbon. This carbon is distributed on the bone earth, resulting in animal charcoal.
What is the main chemical compound used in the electrolytic production of phosphorus?
- Sulphuric acid
- Hydrochloric acid
- Nitric acid
- Phosphoric acid
Correct Answer: Sulphuric acid
Correct Answer Explanation: The electrolytic production of phosphorus involves the decomposition of bone ash with sulphuric acid. This process is more cost-effective and cleaner than traditional methods.
Which of these materials is NOT typically used in the preparation of cements?
- Drying oils
- Resins
- Rubber
- Cotton fibers
Correct Answer: Cotton fibers
Correct Answer Explanation: Cotton fibers are not typically used in the preparation of cements. Cements are typically made from materials like drying oils, resins, rubber, and glue, which contribute to their bonding properties.
What is the primary purpose of water-glass in cement mixtures?
- To increase water resistance
- To reduce brittleness
- To improve flexibility
- To act as a binder
Correct Answer: To act as a binder
Correct Answer Explanation: Water-glass, also known as soluble glass, is a valuable ingredient in cement mixtures because it acts as a binder. It combines with lime to create durable, stone-like adhesives.
What is the main function of alum in paste mixtures?
- To increase water resistance
- To enhance the adhesive power
- To reduce brittleness
- To improve flexibility
Correct Answer: To enhance the adhesive power
Correct Answer Explanation: Alum enhances the adhesive power of paste by forming a leather-like compound with glue, making the paste more resistant to decomposition. This strengthens the adhesive bond.
Which of these glue stocks is typically used for producing gilder’s glue?
- Fish bladders
- Animal bones
- Hide and skin scraps
- Waste paper
Correct Answer: Hide and skin scraps
Correct Answer Explanation: Gilder’s glue is a high-quality glue prepared from selected scraps of hide and skin. It is typically bleached with chloride of lime to achieve its characteristic whiteness.
What is the main difference between oil cements and resinous cements?
- Oil cements are water-resistant, while resinous cements are not.
- Oil cements are typically used for joining metal, while resinous cements are typically used for joining wood.
- Oil cements are derived from natural sources, while resinous cements are synthetically produced.
- Oil cements rely on the chemical interaction of drying oils with basic substances, while resinous cements rely on the solidification of natural plant exudates.
Correct Answer: Oil cements rely on the chemical interaction of drying oils with basic substances, while resinous cements rely on the solidification of natural plant exudates.
Correct Answer Explanation: Oil cements rely on the chemical interaction of drying oils with basic substances to form insoluble soaps, which act as the cement. Resinous cements, on the other hand, are made from natural plant exudates called resins. These substances melt and solidify, forming strong adhesives.
What is the main advantage of using glue and starch pastes in cement mixtures?
- They increase the water resistance of the cement.
- They make the cement more flexible.
- They decrease the brittleness of the cement.
- They improve the adhesion of the cement.
Correct Answer: They decrease the brittleness of the cement.
Correct Answer Explanation: Adding glue and starch pastes to cement mixtures can decrease their brittleness, making them more resilient to cracking. However, this also makes the cement less water-resistant.
What is the main source of isinglass?
- Animal bones
- Fish bladders
- Hide and skin scraps
- Waste paper
Correct Answer: Fish bladders
Correct Answer Explanation: Isinglass is a valuable product derived from fish bladders. It is used in culinary and medicinal applications, as well as in the production of glue and gelatine.
Which of these materials is NOT a common ingredient in hectograph mass?
- Gelatine
- Glycerine
- Water
- Starch
Correct Answer: Starch
Correct Answer Explanation: Hectograph mass is a gelatine-based mixture used for making hectograph copies. It typically contains gelatine, glycerine, and water. Starch is not a common ingredient in hectograph mass.
What is the main advantage of using glycerine-based cements for underwater applications?
- They are water-resistant.
- They solidify quickly.
- They are highly flexible.
- They are very strong.
Correct Answer: They solidify quickly.
Correct Answer Explanation: Glycerine-based cements are particularly useful for underwater applications because they solidify quickly. This rapid hardening allows them to bond effectively in wet environments.
What is the main purpose of using formaldehyde in glue and gelatine solutions?
- To increase the adhesive power
- To reduce the brittleness
- To act as a preservative
- To enhance the flexibility
Correct Answer: To act as a preservative
Correct Answer Explanation: Formaldehyde is a colorless gas with strong antiseptic properties. It is used in the production of formo-gelatine and as a preservative in glue and gelatine solutions to prevent microbial growth and spoilage.
What is the approximate percentage of glue that can be obtained from tannery waste?
- 10-15%
- 20-25%
- 30-35%
- 44-46%
Correct Answer: 44-46%
Correct Answer Explanation: Tannery waste can yield a surprisingly high percentage of glue, typically around 44-46%. This highlights the potential for utilizing byproducts in the production of glue.
What is the typical percentage of moisture, dirt, and salt that should be present in dry, uncured glue stock?
- Less than 5%
- 10%
- 15%
- 20%
Correct Answer: 10%
Correct Answer Explanation: The moisture, dirt, and salt content in dry, uncured glue stock should not exceed 10%. This indicates the importance of quality control in raw materials.
What is the approximate percentage of fat that can be extracted from bones in the head, ribs, and shoulder blades?
- 5-7%
- 10-12%
- 15-17%
- 18-20%
Correct Answer: 12-13%
Correct Answer Explanation: Bones in the head, ribs, and shoulder blades typically yield 12-13% of fat. The thigh and leg bones have a higher yield, ranging from 18-19%.
What is the approximate percentage of phosphorus that can be obtained from bones during the extraction process?
- 15-20%
- 10-12%
- 8-11%
- 5-7%
Correct Answer: 8-11%
Correct Answer Explanation: The actual yield of phosphorus from bones is typically between 8-11%. This indicates that some loss of phosphorus occurs during the extraction process.
What is the approximate percentage of ammonia in the ammoniacal liquor produced during the making of animal charcoal?
- 2-4%
- 5-7%
- 10%
- 15-20%
Correct Answer: 10%
Correct Answer Explanation: The ammoniacal liquor produced during the making of animal charcoal contains on average 10% of ammonia. This demonstrates the potential for recovering valuable byproducts from the process.
What is the approximate amount of animal charcoal that can be obtained from 2000 lbs of raw bone?
- 500-600 lbs
- 800-900 lbs
- 1180-1220 lbs
- 1500-1600 lbs
Correct Answer: 1180-1220 lbs
Correct Answer Explanation: 2000 lbs of raw bone typically yield about 1180-1220 lbs of animal charcoal, along with other valuable byproducts. This showcases the scale of animal charcoal production.
What is the approximate amount of dry glue that can be obtained from 100 lbs of solid and compact bones?
- 5-10 lbs
- 10-15 lbs
- 15-20 lbs
- 25-30 lbs
Correct Answer: 15 lbs
Correct Answer Explanation: Solid and compact bones yield on average 15% of dry glue. This means that 100 lbs of these bones would yield approximately 15 lbs of dry glue.
What is the approximate percentage of calcium phosphate in the basic calcium phosphate precipitate obtained from bone extraction liquor?
- 40-50%
- 50-60%
- 65%
- 75-80%
Correct Answer: 65%
Correct Answer Explanation: The basic calcium phosphate precipitate obtained from the liquor from bone extraction typically contains 65% calcium phosphate, along with other components like water, calcium carbonate, and impurities.
What is the approximate percentage of water in the crude phosphorus obtained by distillation?
- 1-2%
- 3-4%
- 4-6%
- 7-9%
Correct Answer: 4-6%
Correct Answer Explanation: The crude phosphorus obtained by distillation typically contains about 4-6% water. This emphasizes the need for proper drying techniques.
What is the approximate strength of a 10% solution of gelatinized glue, in terms of the load it can withstand in the “Artillery Werkstätte” breaking test?
- 12-64 grammes
- 70-120 kilogrammes
- 150-200 kilogrammes
- 250-300 kilogrammes
Correct Answer: 12-64 grammes
Correct Answer Explanation: The strength of gelatinized glue varies significantly, but a 10% solution typically withstands a load of between 12-64 grammes in the “Artillery Werkstätte” breaking test.
What is the main difference between Russian glue and gilder’s glue?
- Russian glue is typically made from animal bones, while gilder’s glue is made from hide and skin scraps.
- Russian glue is typically dark and opaque, while gilder’s glue is typically light and translucent.
- Russian glue is typically used for construction purposes, while gilder’s glue is typically used for art and crafts.
- Russian glue is typically produced through a dry process, while gilder’s glue is typically produced through a wet process.
Correct Answer: Russian glue is typically dark and opaque, while gilder’s glue is typically light and translucent.
Correct Answer Explanation: Russian glue is typically opaque and white due to the addition of white lead or other mineral substances, while gilder’s glue is a high-quality glue prepared from selected scraps of hide and skin and bleached with chloride of lime, giving it a light, translucent quality.
Which of the following is a common example of a paste made from starch?
- Glue paste
- Starch paste
- Hectograph mass
- Glaziers’ putty
Correct Answer: Starch paste
Correct Answer Explanation: Starch paste is a common example of a paste made from starch. It is used for a variety of purposes, including sticking paper together, creating paper mache, and even as a thickener in cooking.
What is the main reason why bones honeycombed by putrefaction are of little value to the glue boiler?
- They yield less glue.
- They produce a weaker glue.
- They have an unpleasant odor.
- They contaminate the glue.
Correct Answer: They yield less glue.
Correct Answer Explanation: Bones honeycombed by putrefaction are of little value to the glue boiler because they yield less glue. This is due to the decomposition of the glue-yielding tissue by bacteria.
What is the approximate yield of fat from steamed bones?
- 1-2%
- 3-4%
- 4-5%
- 6-7%
Correct Answer: 4-5%
Correct Answer Explanation: Steamed bones can yield 4-5% of fat, which is a lower yield than extraction with solvents.
What is the main reason for thoroughly freeing bones from acid after treatment with hydrochloric acid?
- To prevent the glue from becoming brittle.
- To prevent the glue from being contaminated.
- To prevent the glue from becoming discolored.
- To prevent the glue from becoming too strong.
Correct Answer: To prevent the glue from being contaminated.
Correct Answer Explanation: The bones should be thoroughly freed from acid after treatment with hydrochloric acid to prevent the glue from being contaminated. Even a small amount of acid can affect the quality of the finished glue.
Which type of glue is typically used for making hectograph copies?
- Animal glue
- Fish glue
- Vegetable glue
- Synthetic glue
Correct Answer: Animal glue
Correct Answer Explanation: Hectograph mass is a gelatine-based mixture that typically uses animal glue. The gelatine’s ability to solidify and form a smooth surface makes it suitable for creating copies.
What is the main reason why glue and starch pastes are less water-resistant than cements?
- They are not as strong.
- They are not as flexible.
- They are not as durable.
- They are not as chemically stable.
Correct Answer: They are not as chemically stable.
Correct Answer Explanation: Glue and starch pastes are less water-resistant than cements because they are not as chemically stable. The glue and starch can dissolve in water, weakening the adhesive bond.
What is the main purpose of using lime cements in construction?
- To bind bricks and mortar.
- To seal cracks in walls.
- To create a waterproof barrier.
- To create a decorative finish.
Correct Answer: To bind bricks and mortar.
Correct Answer Explanation: Lime cements are commonly used in construction to bind bricks and mortar. The lime reacts with water to form a strong, durable adhesive.
Which type of cement is typically used for securing window panes?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Oil cement
Correct Answer Explanation: Glaziers’ putty, which is a durable oil cement, is typically used to secure window panes. It provides a strong, flexible bond that can withstand changes in temperature and humidity.
What is the main difference between a paste and a mucilage?
- A paste is typically thicker than a mucilage.
- A paste is typically used for sticking paper, while a mucilage is typically used for sticking envelopes.
- A paste is typically made from starch, while a mucilage is typically made from gum arabic.
- A paste is typically used for a variety of purposes, while a mucilage is typically used for a specific purpose.
Correct Answer: A paste is typically thicker than a mucilage.
Correct Answer Explanation: Pastes are typically thicker and more viscous than mucilages. Mucilages are typically thinner and more watery.
Which type of cement is typically used for joining metal?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Oil cement
Correct Answer Explanation: Oil cements are commonly used for joining metal. They form a strong bond that can withstand the stresses and vibrations associated with metalwork.
What is the main reason why bones of older animals yield more solid glue than those of younger animals?
- The glue-yielding substance in older animals has undergone more transformations.
- The bones of older animals are denser.
- The bones of older animals contain more collagen.
- The bones of older animals are less porous.
Correct Answer: The glue-yielding substance in older animals has undergone more transformations.
Correct Answer Explanation: The glue-yielding substance in older animals has undergone more transformations, resulting in a more solid and durable glue. This is why bones of older animals are preferred for glue production.
What is the main advantage of using formaldehyde in glue solutions?
- It increases the adhesive power.
- It reduces the brittleness.
- It acts as a preservative.
- It enhances the flexibility.
Correct Answer: It acts as a preservative.
Correct Answer Explanation: Formaldehyde acts as a preservative in glue solutions, preventing microbial growth and spoilage. This extends the shelf life of the glue.
What is the main difference between glue made from animal bones and glue made from fish bladders?
- Bone glue is typically stronger than fish glue.
- Bone glue is typically more flexible than fish glue.
- Bone glue is typically more water-resistant than fish glue.
- Bone glue is typically more transparent than fish glue.
Correct Answer: Bone glue is typically stronger than fish glue.
Correct Answer Explanation: Bone glue is typically stronger than fish glue. This is because the collagen in bones is denser and more tightly packed than the collagen in fish bladders.
Which type of cement is typically used for sealing cracks in walls?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Resinous cement
Correct Answer Explanation: Resins are typically used for sealing cracks in walls. They can be applied as a thick paste and will harden, forming a strong seal.
What is the main purpose of using water-glass in cement mixtures?
- To increase water resistance
- To reduce brittleness
- To improve flexibility
- To act as a binder
Correct Answer: To act as a binder
Correct Answer Explanation: Water-glass, also known as soluble glass, is a valuable ingredient in cement mixtures because it acts as a binder. It combines with lime to create durable, stone-like adhesives.
Which of these materials is NOT a common ingredient in cement mixtures?
- Drying oils
- Resins
- Rubber
- Cotton fibers
Correct Answer: Cotton fibers
Correct Answer Explanation: Cotton fibers are not typically used in the preparation of cements. Cements are typically made from materials like drying oils, resins, rubber, and glue, which contribute to their bonding properties.
What is the main difference between glue and gelatine?
- Glue is derived from animal bones, while gelatine is derived from animal skins.
- Glue is used for construction purposes, while gelatine is used in food and medicine.
- Glue is typically opaque, while gelatine is typically translucent.
- Glue is produced through a dry process, while gelatine is produced through a wet process.
Correct Answer: Glue is typically opaque, while gelatine is typically translucent.
Correct Answer Explanation: Glue is typically opaque, often appearing brown or yellowish, while gelatine is typically translucent and often colorless. This difference is due to the specific processing methods and the different raw materials used.
What is the approximate percentage of glue that can be obtained from scraps of parchment and bullocks’ feet?
- 20-30%
- 30-40%
- 40-50%
- 62%
Correct Answer: 62%
Correct Answer Explanation: Scraps of parchment and bullocks’ feet can yield up to 62% of their weight in glue. This makes them highly valuable to the glue boiler.
What is the main reason why green salted glue stock should have no excess of salt and moisture?
- To prevent the glue from becoming brittle.
- To prevent the glue from becoming discolored.
- To prevent the glue from being contaminated.
- To prevent the glue from becoming too strong.
Correct Answer: To prevent the glue from becoming contaminated.
Correct Answer Explanation: Green salted glue stock should have no excess of salt and moisture to prevent the glue from becoming contaminated. Salt and moisture can promote microbial growth, affecting the quality of the glue.
What is the main difference between oil cements and resinous cements?
- Oil cements are water-resistant, while resinous cements are not.
- Oil cements are typically used for joining metal, while resinous cements are typically used for joining wood.
- Oil cements are derived from natural sources, while resinous cements are synthetically produced.
- Oil cements rely on the chemical interaction of drying oils with basic substances, while resinous cements rely on the solidification of natural plant exudates.
Correct Answer: Oil cements rely on the chemical interaction of drying oils with basic substances, while resinous cements rely on the solidification of natural plant exudates.
Correct Answer Explanation: Oil cements rely on the chemical interaction of drying oils with basic substances to form insoluble soaps, which act as the cement. Resinous cements, on the other hand, are made from natural plant exudates called resins. These substances melt and solidify, forming strong adhesives.
Which of these materials is NOT a common ingredient in cement mixtures?
- Drying oils
- Resins
- Rubber
- Cotton fibers
Correct Answer: Cotton fibers
Correct Answer Explanation: Cotton fibers are not typically used in the preparation of cements. Cements are typically made from materials like drying oils, resins, rubber, and glue, which contribute to their bonding properties.
What is the main advantage of using glycerine-based cements for underwater applications?
- They are water-resistant.
- They solidify quickly.
- They are highly flexible.
- They are very strong.
Correct Answer: They solidify quickly.
Correct Answer Explanation: Glycerine-based cements are particularly useful for underwater applications because they solidify quickly. This rapid hardening allows them to bond effectively in wet environments.
What is the main purpose of using formaldehyde in glue and gelatine solutions?
- To increase the adhesive power
- To reduce the brittleness
- To act as a preservative
- To enhance the flexibility
Correct Answer: To act as a preservative
Correct Answer Explanation: Formaldehyde is a colorless gas with strong antiseptic properties. It is used in the production of formo-gelatine and as a preservative in glue and gelatine solutions to prevent microbial growth and spoilage.
What is the approximate percentage of glue that can be obtained from tannery waste?
- 10-15%
- 20-25%
- 30-35%
- 44-46%
Correct Answer: 44-46%
Correct Answer Explanation: Tannery waste can yield a surprisingly high percentage of glue, typically around 44-46%. This highlights the potential for utilizing byproducts in the production of glue.
What is the typical percentage of moisture, dirt, and salt that should be present in dry, uncured glue stock?
- Less than 5%
- 10%
- 15%
- 20%
Correct Answer: 10%
Correct Answer Explanation: The moisture, dirt, and salt content in dry, uncured glue stock should not exceed 10%. This indicates the importance of quality control in raw materials.
What is the approximate percentage of fat that can be extracted from bones in the head, ribs, and shoulder blades?
- 5-7%
- 10-12%
- 15-17%
- 18-20%
Correct Answer: 12-13%
Correct Answer Explanation: Bones in the head, ribs, and shoulder blades typically yield 12-13% of fat. The thigh and leg bones have a higher yield, ranging from 18-19%.
What is the approximate percentage of phosphorus that can be obtained from bones during the extraction process?
- 15-20%
- 10-12%
- 8-11%
- 5-7%
Correct Answer: 8-11%
Correct Answer Explanation: The actual yield of phosphorus from bones is typically between 8-11%. This indicates that some loss of phosphorus occurs during the extraction process.
What is the approximate percentage of ammonia in the ammoniacal liquor produced during the making of animal charcoal?
- 2-4%
- 5-7%
- 10%
- 15-20%
Correct Answer: 10%
Correct Answer Explanation: The ammoniacal liquor produced during the making of animal charcoal contains on average 10% of ammonia. This demonstrates the potential for recovering valuable byproducts from the process.
What is the approximate amount of animal charcoal that can be obtained from 2000 lbs of raw bone?
- 500-600 lbs
- 800-900 lbs
- 1180-1220 lbs
- 1500-1600 lbs
Correct Answer: 1180-1220 lbs
Correct Answer Explanation: 2000 lbs of raw bone typically yield about 1180-1220 lbs of animal charcoal, along with other valuable byproducts. This showcases the scale of animal charcoal production.
What is the approximate amount of dry glue that can be obtained from 100 lbs of solid and compact bones?
- 5-10 lbs
- 10-15 lbs
- 15-20 lbs
- 25-30 lbs
Correct Answer: 15 lbs
Correct Answer Explanation: Solid and compact bones yield on average 15% of dry glue. This means that 100 lbs of these bones would yield approximately 15 lbs of dry glue.
What is the approximate percentage of calcium phosphate in the basic calcium phosphate precipitate obtained from bone extraction liquor?
- 40-50%
- 50-60%
- 65%
- 75-80%
Correct Answer: 65%
Correct Answer Explanation: The basic calcium phosphate precipitate obtained from the liquor from bone extraction typically contains 65% calcium phosphate, along with other components like water, calcium carbonate, and impurities.
What is the approximate percentage of water in the crude phosphorus obtained by distillation?
- 1-2%
- 3-4%
- 4-6%
- 7-9%
Correct Answer: 4-6%
Correct Answer Explanation: The crude phosphorus obtained by distillation typically contains about 4-6% water. This emphasizes the need for proper drying techniques.
What is the approximate strength of a 10% solution of gelatinized glue, in terms of the load it can withstand in the “Artillery Werkstätte” breaking test?
- 12-64 grammes
- 70-120 kilogrammes
- 150-200 kilogrammes
- 250-300 kilogrammes
Correct Answer: 12-64 grammes
Correct Answer Explanation: The strength of gelatinized glue varies significantly, but a 10% solution typically withstands a load of between 12-64 grammes in the “Artillery Werkstätte” breaking test.
What is the main difference between Russian glue and gilder’s glue?
- Russian glue is typically made from animal bones, while gilder’s glue is made from hide and skin scraps.
- Russian glue is typically dark and opaque, while gilder’s glue is typically light and translucent.
- Russian glue is typically used for construction purposes, while gilder’s glue is typically used for art and crafts.
- Russian glue is typically produced through a dry process, while gilder’s glue is typically produced through a wet process.
Correct Answer: Russian glue is typically dark and opaque, while gilder’s glue is typically light and translucent.
Correct Answer Explanation: Russian glue is typically opaque and white due to the addition of white lead or other mineral substances, while gilder’s glue is a high-quality glue prepared from selected scraps of hide and skin and bleached with chloride of lime, giving it a light, translucent quality.
Which of the following is a common example of a paste made from starch?
- Glue paste
- Starch paste
- Hectograph mass
- Glaziers’ putty
Correct Answer: Starch paste
Correct Answer Explanation: Starch paste is a common example of a paste made from starch. It is used for a variety of purposes, including sticking paper together, creating paper mache, and even as a thickener in cooking.
What is the main reason why bones honeycombed by putrefaction are of little value to the glue boiler?
- They yield less glue.
- They produce a weaker glue.
- They have an unpleasant odor.
- They contaminate the glue.
Correct Answer: They yield less glue.
Correct Answer Explanation: Bones honeycombed by putrefaction are of little value to the glue boiler because they yield less glue. This is due to the decomposition of the glue-yielding tissue by bacteria.
What is the approximate yield of fat from steamed bones?
- 1-2%
- 3-4%
- 4-5%
- 6-7%
Correct Answer: 4-5%
Correct Answer Explanation: Steamed bones can yield 4-5% of fat, which is a lower yield than extraction with solvents.
What is the main reason for thoroughly freeing bones from acid after treatment with hydrochloric acid?
- To prevent the glue from becoming brittle.
- To prevent the glue from being contaminated.
- To prevent the glue from becoming discolored.
- To prevent the glue from becoming too strong.
Correct Answer: To prevent the glue from being contaminated.
Correct Answer Explanation: The bones should be thoroughly freed from acid after treatment with hydrochloric acid to prevent the glue from being contaminated. Even a small amount of acid can affect the quality of the finished glue.
Which type of glue is typically used for making hectograph copies?
- Animal glue
- Fish glue
- Vegetable glue
- Synthetic glue
Correct Answer: Animal glue
Correct Answer Explanation: Hectograph mass is a gelatine-based mixture that typically uses animal glue. The gelatine’s ability to solidify and form a smooth surface makes it suitable for creating copies.
What is the main reason why glue and starch pastes are less water-resistant than cements?
- They are not as strong.
- They are not as flexible.
- They are not as durable.
- They are not as chemically stable.
Correct Answer: They are not as chemically stable.
Correct Answer Explanation: Glue and starch pastes are less water-resistant than cements because they are not as chemically stable. The glue and starch can dissolve in water, weakening the adhesive bond.
What is the main purpose of using lime cements in construction?
- To bind bricks and mortar.
- To seal cracks in walls.
- To create a waterproof barrier.
- To create a decorative finish.
Correct Answer: To bind bricks and mortar.
Correct Answer Explanation: Lime cements are commonly used in construction to bind bricks and mortar. The lime reacts with water to form a strong, durable adhesive.
Which type of cement is typically used for securing window panes?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Oil cement
Correct Answer Explanation: Glaziers’ putty, which is a durable oil cement, is typically used to secure window panes. It provides a strong, flexible bond that can withstand changes in temperature and humidity.
What is the main difference between a paste and a mucilage?
- A paste is typically thicker than a mucilage.
- A paste is typically used for sticking paper, while a mucilage is typically used for sticking envelopes.
- A paste is typically made from starch, while a mucilage is typically made from gum arabic.
- A paste is typically used for a variety of purposes, while a mucilage is typically used for a specific purpose.
Correct Answer: A paste is typically thicker than a mucilage.
Correct Answer Explanation: Pastes are typically thicker and more viscous than mucilages. Mucilages are typically thinner and more watery.
Which type of cement is typically used for joining metal?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Oil cement
Correct Answer Explanation: Oil cements are commonly used for joining metal. They form a strong bond that can withstand the stresses and vibrations associated with metalwork.
What is the main reason why bones of older animals yield more solid glue than those of younger animals?
- The glue-yielding substance in older animals has undergone more transformations.
- The bones of older animals are denser.
- The bones of older animals contain more collagen.
- The bones of older animals are less porous.
Correct Answer: The glue-yielding substance in older animals has undergone more transformations.
Correct Answer Explanation: The glue-yielding substance in older animals has undergone more transformations, resulting in a more solid and durable glue. This is why bones of older animals are preferred for glue production.
What is the main advantage of using formaldehyde in glue solutions?
- It increases the adhesive power.
- It reduces the brittleness.
- It acts as a preservative.
- It enhances the flexibility.
Correct Answer: It acts as a preservative.
Correct Answer Explanation: Formaldehyde acts as a preservative in glue solutions, preventing microbial growth and spoilage. This extends the shelf life of the glue.
What is the main difference between glue made from animal bones and glue made from fish bladders?
- Bone glue is typically stronger than fish glue.
- Bone glue is typically more flexible than fish glue.
- Bone glue is typically more water-resistant than fish glue.
- Bone glue is typically more transparent than fish glue.
Correct Answer: Bone glue is typically stronger than fish glue.
Correct Answer Explanation: Bone glue is typically stronger than fish glue. This is because the collagen in bones is denser and more tightly packed than the collagen in fish bladders.
Which type of cement is typically used for sealing cracks in walls?
- Oil cement
- Resinous cement
- Rubber cement
- Glue cement
Correct Answer: Resinous cement
Correct Answer Explanation: Resins are typically used for sealing cracks in walls. They can be applied as a thick paste and will harden, forming a strong seal.