CHEMISTRY INVESTIGATORY
PROJECT
Name:- Niranjan Mahendra Gavali
Class:- XI A
Roll no:- 11A15
SNBP INTERNATIONAL SCHOOL
MORWADI, PIMPRI, PUNE
CBSE AFFILIATION NO. 1130522
Certificate
This is to certify that,
Name of the Student-
Class -
Has successfully completed the project
Name of the Project-
Under the guidance and observation of
Name of the Teacher-
During the academic session 2022-2023, in the partial fulfilment of
PracticalExamination conducted by AISSCE-2023.
Signature of the Teacher with Date-
Signature of the Principal with Date-
School Seal
Signature of the External Examiner-
Acknowledgement
I, Niranjan Mahendra Gavali, student of SNBP
International School, Morwadi, Pimpri, Pune;
affiliated to CBSE Board vide Affiliation No.
1130522; would like to express my gratitude to
the Institution for the support and knowledge I
received in the school. I feel in debt towards
Principal Sweta Paithankar Madam and my
teacher Komal Bandekar Ma’am who gave me
an opportunity the to do project (name of
project) I, once again thank the school for
providing me all the facilities and excellent
education. I am also grateful to my friends and
family for their faith in me.
Thank You All!
Signature of Student ———————————
Date ________________
Signature of the Receiver___________________
INDEX
Serial No. Contents
1. CERTIFICATE
2. ACKNOWLEDGEMENT
3. AIM & APPARATUS
4. INTRODUCTION
5. THEORY
6. DIAGRAMS
7. OBSERVATIONS
8. RESULTS
9. APPLICATIONS
10. BIBLIOGRAPHY
Aim:- Study the effect of acids and bases on
the tensile strength of fibers.
Apparatus:- Apparatus : Hook, Weight Hanger
and Weights.
(b) Materials and Chemicals : Wool, Cotton and
Nylon Fibres, dilute
solution of hydrochloric acid and sodium
hydroxide.
Introduction
Depending upon the sources, the various types of
fibres can be classified into the following three
main categories :
(i) Animal fibres e.g. Wool & Silk.
(ii) Vegetable Fibres e.g. Cotton & Linen.
(iii) Synthetic Fibres e.g. Nylon & Polyester.
Besides their chemical composition and
properties, most important property of these
fibres is their tensile strength. To determine the
tensile strength of any fibre, it is tied to a hook
at one end and weighted are slowly added to the
other end until the fibre break. Since peptide
bonds are more easily hydrolyzed by bases than
acids therefore wool and silk are affected by
basis not by acids. It is because of this reason
that wool and silk threads breakup into
fragments and ultimately dissolve in alkalines.
In other words acids decreases the tensile
strength of vegetable fibres. In contrast,
synthetics fibres such as nylon & polyester
practically remains unaffected by both
acids and bases.
Theory
Procedure :-
(i) Cut out equal lengths of wool, cotton and
nylon threads from given sample of nearly
same diameter.
(ii) Soak the woolen thread in a dilute
solution of sodium hydroxide for five
minutes. Take it out from hydroxide
solution and wash it thoroughly with
water and then dry either by keeping it in
the sun or in an over maintained at a
temperature of about 400C.
(iii) Now take another piece of woolen thread
of the same size and diameter and soak it
in a dilute solution of hydrochloric acid for
five minutes. Take it out, wash thoroughly
with water, dry and determine the tensile
strength again.
(iv) Repeat the above procedure for the
samples of cotton and nylon fibre.
Diagrams
Applications
Natural fibers being cost effective and
abundantly available yields high potential in
various industrial and commercial
applications such as in the interior
applications of the passenger cars, panels for
partition and false ceiling, partition boards,
roof tiles, coir fibers in packaging, furniture
applications, as insulating materials in low
energy houses, geo-textiles for soil protection
and erosion control, enhancing barrier
properties, composites etc.
Observations
(i) The tensile strength of woolen fibre
decreases on soaking in alkalies but
practically remains unaffected on
soaking in acids.
(ii) The tensile strength of cotton fibre
decreases on soaking in acids but
remains practically unaffected on
soaking in alkalies.
(iii) The tensile strength of nylon fibres
remain practically unaffected on
soaking either in acids or in alkalies.
Results
Sr. no. Type of fibre Minimum
weight
1. Wool 750g
2. Cotton 75g
3. Nylon 375g
Sr. Type of Weight Weight Weight
no. Fibre Required required required
To break to break to break
untreated after after
fibre soaking soaking
in dilute in dilute
alkali acid
1. Wool 750g 700g 750g
2. Cotton 75g 75g 50g
3. Nylon 375g 375g 375g
Bibliography
1. https://www.wikipedia.com/
2. https://www.techopedia.com/
3. https://labex.com/
4. https://www.icbe.com/
Reference Books:-
1. Handbook of tensile strength of fibre
2. Fibreshed
