Silk was discovered in China around 3500 BC during the reign of Emperor Huang-ti. Because of its lustre and fine quality, it was regarded as one of the most valuable fibres at the time. Emperors only used it at the time, and it was kept secret for hundreds of years. It was later spread throughout the world through trade. It used to travel along what was known as the ‘Silk route’.
According to historians, silk was also produced in India. Its applications were discovered during the Indus Valley civilisation.
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Definition: Silk is a natural protein fibre used to make textiles. It is an important animal fibre derived from silkworms. Silkworms of various species produce various types of silk. It can be distinguished by its lustre and texture. Kosa, Tussar, Mooga, and other names are examples. Silk moths of various species produce them. The mulberry silk moth is one of the most common. |
Silk in Chemistry Questions with Solutions
Q1. Which of the following silk varieties is not manufactured in India?
a.) Muga silk
b.) Mulberry silk
c.) Tussar silk
d.) American silk
Correct Answer – (d.) American silk.
Q2. How many stages are there in the silkworm’s life cycle?
a.) 3
b.) 4
c.) 5
d.) 6
Correct Answer – (b.) 4.
Q3. Which of the following species produces higher quality silk?
a.) Attacus atlas
b.) Bombyx mori
c.) Attacus ricini
d.) Antheraea assamensis
Correct Answer – (b.) Bombyx mori.
Q4. Silk is produced by ____.
a.) Adult moth
b.) Cocoon
c.) Larva
d.) All of the above
Correct Answer – (c.) Larva.
Q5. Which of the following is called artificial silk?
a.) Nylon
b.) Rayon
c.) Polyester
d.) Acrylic
Correct Answer – (b.) Rayon
Q6. What is silk?
Answer: Silk is a natural protein fibre that can be used to make textiles. It is an important animal fibre derived from silkworms.
Q7. What is the process of taking out silk threads from the cocoon called?
Answer: The process of extracting threads from a cocoon for use as silk is known as reeling the silk. Reeling is done using special machines that unwind the silk threads or fibres from the cocoon.
Q8. How many eggs does a female silk moth lay at a time?
Answer: A female silk moth can lay hundreds of eggs at a time.
Q9. What is sericulture?
Answer: Sericulture is the cultivation of silkworms and the extraction of silk from them. Domestic silk moth caterpillars (also known as ‘Bombyx Mori’) are the most commonly used silkworm species in sericulture. Other silkworm species, such as Eri, Muga, and Tasar, are also raised for the production of ‘wild silks.’
Q10. List the different types of silk.
Answer: The different types of silk are:
- Mulberry silk
- Spider silk.
- Sea silk
- Tussar silk
- Eri silk
- Muga silk (An Assam silk)
- Art silk (Bamboo silk)
Q11. What is the life cycle of a silkworm?
Answer: The mulberry silkworm’s life cycle lasts 45-55 days and includes the stages – egg, larva, pupa, and moth.
Q12. How to identify whether the silk is real or not?
Answer: Following are the ways in which real silk can be identified:
- Real silk is completely smooth to the touch, with a soft, almost waxy feel. In addition, if you scrunch it up in your hand, you should hear a crunching sound.
- The ring test is a common and simple method because silk is naturally flexible and smooth. The only requirement is that the silk not be too heavy. Pull a lightweight silk fabric through a ring if you have one. It’s real silk if it can be threaded and pulled through easily.
Q13. What precautions should be taken to preserve silk?
Answer: Silk is a natural fibre and is very costly. Thus it should be stored very carefully. Some precautions to keep in mind are as follows:
- The best way to store silk is to hang it in a cotton garment bag to keep bugs away. Fold the garments with acid-free tissue paper and store them in a cotton storage box if storing for an extended period of time.
- Silk should never be spot-treated – If you drop something on a silk item and wash only the soiled portion, the soiled portion will fade quickly.
- Never dry silk garments in the dryer.
Q14. What are the disadvantages of silk?
Answer: Some disadvantages of silk are:
- Silk is among the most expensive fabrics available.
- Silk requires more maintenance than other fabrics.
- Silk fades quickly in direct sunlight. A new garment dried outside can appear old and worn.
- The fabric has a tendency to yellow over time and is especially susceptible to perspiration stains.
- Travelling with silk garments can be inconvenient because silk wrinkles easily and necessitates the use of a steam iron.
- Since silk absorbs water, liquid stains are visible.
Q15. Explain the properties of silk.
Answer: The properties of silk are as follows:
- Strength: Silk is one of the strongest fibres.
- Breathability: Silk is a lightweight, breathable fabric. It reduces the risk of overheating while you go about your day.
- Elasticity: Silk clothes retain their shape well if properly cared for. Silk is flexible and has some elasticity, so it can, to some extent, pull itself back into shape after stretching.
- Absorbency: Silk is relatively absorbent. Water, on the other hand, weakens the fibres, so wash your silk with care.
- Thermal regulation: Silk regulates body temperature, so it can keep you cool in hot weather and warm in cold weather.
- Speed of drying: Silk dries quickly, making it ideal for managing laundry or going about your daily activities.
- Shine: Silk fibres are smooth and straight, unlike wool, which has scaliness that can be seen under a microscope. This distinction makes silk smoother to the touch and shinier to the eye, resulting in an overall luxurious feel.
Practice Questions on Silk
Q1. The protein in silk is known as ____.
a.) Casein
b.) Fibroin
c.) Sericin
d.) Both (b) and (c)
Q2. Silkworms are the ____ of silk moths.
a.) Eggs
b.) Cocoon
c.) Caterpillar
d.) Larva
Q3. What are the uses of silk?
Q4. What is artificial silk?
Q5. How is silk processed?
Click the PDF to check the answers for Practice Questions. Download PDF
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