Page 101 - Chemistry - XI

CH COOH
3
S. No. Name of Fibre Weight required to break the fi bre

1. Cotton 400 g
2. Silk 120 g
3. Nylon 1750 g

4. Terylene 710 g

NaOH
S. No. Name of Fibre Weight required to break the fi bre
1. Cotton 410 g

2. Silk 120 g
3. Nylon 1280 g
4. Terylene 700 g

NH OH
4
S. No. Name of Fibre Weight required to break the fi bre
1. Cotton 400 g

2. Silk 110 g
3. Nylon 1300 g
4. Terylene 700 g

Result
Note down the tensile strengths of diff erent sets in acidic/basic conditions.

Precautions

1. Same length of thread in each case should be used before putting weight in the pan.
2. The volume and molarity of acids and bases should be same.
3. Threads should be completely dipped and dried before tying their ends to hook and pan.

VIVA VOCE

Q1. What type of bonds are present in fi bres?
Ans. H-bonds

Q2. What is rayon? Why is it called artifi cial silk?
Ans. Rayon is prepared from cellulose. It is shiny like silk, but chemically it is identical to cotton.

Q3. What is terrywool?
Ans. Terylene mixed with wool is called terrywool.

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