CHEMISTRY PROJECT

ON

GLUCOSE CONTENT IN FRUIT JUICES

NAME: Mud i t Chhabra

CLASS: X I I -B

ROLL NUMBER:

SCHOOL: Good ley Pub l i c Schoo l

YEAR: 2012 -2013

SUBMITTED TO: Mrs Shashwat i Sen Gupta

AIM

TO DETERMINE THE AMOUNT OF GLUCOSE

IN FRUIT JUICES.

ACKNOWLEDGEMENT I sincerely express my

gratitude towards my chemistry

teacher Mrs Shashwati Sen Gupta for her expert guidance and suggestions given to me

during this project. I gratefully acknowledge that without her

valuable guidance and comments it would not have

been possible for me to complete this project in time.

Name: Mudit Chhabra Class: XII – B

INTRODUCTIONCarbohydrates are one of the most important bio molecules present in living cells. These are widely

distributed both in plants and animals. Carbohydrates are synthesized by plants by the process known as photosynthesis, given by the reaction.

Glucose so formed is stored as starch , sucrose ,maltose, etc. in various parts of the plants e.g. glucose synthesized by leaves is stored as starch in potato, as sucrose in liquid form in sugarcane and beet root ,as juices in rice , as juices in rice grains etc.

Carbohydrates are regarded as hydrates of carbon and have general formula (CH20) n. Depending on hydrolysis, carbohydrates are of three types:

MONOSACCHARIDES : Carbohydrates which cannot be further hydrolysed to a simpler unit. Eg.glucose and fructose.

DISACCHARIDES: Carbohydrates which yield two MONOSACCHARIDES units on hydrolysis. E.g. sucrose, lactose and maltose.

POLYSACCHARIDES: Carbohydrates which yield large number of MONOSACCHARIDES units on hydrolysis, E.g. starch, glycogen and cellulose.

GlucoseIt is an aldohexose and is most widely distributed monosaccharide. It occurs in large quantity in ripen grapes so it is called grape sugar. It also occurs in most other fruits like honey saps of plants in animal glucose is a source of energy and remains in blood and tissues by the reaction.

An adult on an average contains 5 to 6 grams of glucose in blood which is sufficient to supply energy for 15 minutes. Excess of glucose is stored in liver and glycogen and reconverted into glucose when required

Hormone insulin controls glucose level in blood. A higher glucose level cause a disease called diabetes mellitus and is exerted in urine. Molecular formula of glucose is:

THEORYGlucose reacts with Fehling solution to form red precipitate of cuprous oxide. A known value of Fehling solution is titrated against a standard solution of glucose and then with unknown /

sample of grapes sugar juice, using methylene blue as indicator.

Fehling solution of two types:

A=aq. Copper sulphate cuso4 (aq.)

B=alkaline sodium potassium tartrate

Reaction of glucose and Fehling solutions is an oxidation reaction. A Fehling solution oxidizes aldehyde to carboxylic acid and gets reduced to cu+.

EXPERIMENT 1 APPARATUS REQUIRED

BURETTEPIPETTECONICAL FLASKBURETTE STAND

CHEMICALS REQUIRED

FEHLING SOLUTION OF A AND B

GLUCOSE (SOLID)ORANGE JUICE , APPLE JUICE , PEAR JUICE AND POMEGRANATE JUICEMETHYLENE BLUE

EXPERIMENT FOR FRUIT JUICES

PROCEDURE1. Prepare Fehling solution by mixing equal volumes of Fehling solution A and B.

2. Take fruit juice and dissolve in 250 ml of distilled water, filled up to the mark.

3. Take the burette, clean it with chromic acid, then with distilled water.

4. Fill the burette up to convention point. React the lower meniscus of the fruit juice in burette.

5. Pipette out 20 ml of Fehling solution in conical flask and boil the contents over the gauze.

6. Add fruit juice in hot Fehling solution from burette until the colour of the solution is Pale blue and then drop wise, till the colour just disappears.

Observation table for standard glucose solution

S.NOVOLUME OF FEHLING SOLUTION (ml)

INITIAL READING (ml)

FINAL READING (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE = ml

CALCULATIONS(Standard glucose solution)

Fehling solution = Glucose solution

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

M1*V1 =

M1*20 =

M1 =

Strength of Glucose = Molarity * Molecular Mass

=

=

Observation table for Orange Juice

S.NOVOLUME OF FEHLING SOLUTION (ml)

INITIAL READING (ml)

FINAL READING (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE = ml

CALCULATIONS(Orange juice)

Fehling solution = Glucose solution (Fruit juice)

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

M (orange juice) = M (Fehling)*V (Fehling)/ V (Glucose)

=

M (orange juice) =

Strength of Glucose (orange juice) = Molarity * Molecular Mass

=

=

Percentage of glucose in orange juice =

Strength of Glucose (orange juice)/ Strength of standard Glucose

=

=

Orange juice consists of glucose =

Observation table for Apple Juice

S.NOVOLUME OF FEHLING SOLUTION (ml)

INITIAL READING (ml)

FINAL READING (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE = ml

CALCULATIONS(Apple juice)

Fehling solution = Glucose solution (Fruit juice)

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

M (Apple juice) = M (Fehling)*V (Fehling)/ V (Glucose)

=

M (Apple juice) =

Strength of Glucose (Apple juice) = Molarity * Molecular Mass

=

=

Percentage of glucose in Apple juice =

Strength of Glucose (Apple juice)/ Strength of standard Glucose

=

=

Apple juice consists of glucose =

Observation table for Pear Juice

S.NOVOLUME OF FEHLING SOLUTION (ml)

INITIAL READING (ml)

FINAL READING (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE = ml

CALCULATIONS(Pear juice)

Fehling solution = Glucose solution (Fruit juice)

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

M (Pear juice) = M (Fehling)*V (Fehling)/ V (Glucose)

=

M (Pear juice) =

Strength of Glucose (Pear juice) = Molarity * Molecular Mass

=

=

Percentage of glucose in Pear juice =

Strength of Glucose (Pear juice)/ Strength of standard Glucose

=

=

Pear juice consists of glucose =

Observation table for Pomegranate Juice

S.NOVOLUME OF FEHLING SOLUTION (ml)

INITIAL READING (ml)

FINAL READING (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE = ml

CALCULATIONS(Pomegranate juice)

Fehling solution = Glucose solution (Fruit juice)

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

M (Pomegranate juice) = M (Fehling)*V (Fehling)/ V (Glucose)

=

M (Pomegranate juice) =

Strength of Glucose (Pomegranate juice) = Molarity * Molecular

Mass

=

Percentage of glucose in Pomegranate juice =

Strength of Glucose (Pomegranate juice)/ Strength of standard

Glucose

=

=

Pomegranate juice consists of glucose =

RESULT

Percentage of glucose in ORANGE juice =

Percentage of glucose in APPLE juice =

Percentage of glucose in PEAR juice =

Percentage of glucose in POMEGRANATE

juice =