Page 102 - Chemistry - XI

Q4. What is terrycot?
Ans. Terylene mixed with cotton is terrycot.

Q5. Name two natural polyamide fi bres.
Ans. Wool and silk are natural polyamide fi bres.
Q6. What is the type of nylon fi bre?
Ans. It is polyamide, a synthetic fi bre.

Q7. What is meant by tensile strength of fi bres?
Ans. It is the minimum weight per unit length required to break a fi bre.

Q8. What is the chemical nature of fi bres?
Ans. They are polymers of small molecules called monomers.

Q9. What are fi bres?
Ans. They are thread-like materials which are used for textiles.
Q10. Why does a piece of apple turn brown on exposure to air?
Ans. It is due to formation of hydrated ferric oxide.

Q11. What type of vegetables contain iron ?
Ans. Green leafy vegetables

Q12. Which medicine is used in case of anaemia?
Ans. Folic acid (ferrous sulphate)

Q13. Which metal can be eaten in an elemental form?
Ans. Silver, in the form of silver paper on sweets.

Q14. Which metal is present in haemoglobin?
Ans. Fe (iron)

PROJECT - 8

Introduction
Carbohydrates, fats and proteins are the few basic constituents of plants and animals.

Carbohydrates

Carbohydrates are energy resource produced by green plants. They are made up of C, H and O in the ratio
of 1 : 2 : 1. Some common carbohydrates are glucose, cellulose, starch, etc.

Fats
Fats are important for the body because they provide energy and help in growth. They also help in synthesis
of harmones and provide insulation and padding to the body. Fats and lipids are triglyceride of fatty acids.

Triglycerides can be hydrolysed readily with aqueous sodium hydroxide (NaOH) in which the components
of
of fatty acids are obtained as sodium salts (soaps) and glycerol. Saturated fats are solid at room temperature fatty acids are obtained as sodium salts (soaps) and glycerol. Saturated fats are solid at room temperature
whereas unsaturated fats are in liquid form.
whereas unsaturated fats are in liquid form.

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