revised chemistry project

8/19/2019 Revised Chemistry Project

1/21

CHEMISTRY PROJECT

Presented By:Pranav Bhatia

CSE

0391150!11


2/21

"i#

T$ deter#ine the %$n%entrati$n $& %itri%

a%id 'resent in ri'e &r(it )(i%es*


3/21

CO+TE+TS

Intr$d(%ti$n Str(%t(re $& %itri% a%id ,ses -ey.$rds Titrati$n $& &r(it )(i%es Pr$%ed(re

"''arat(s O/servati$ns Pre%a(ti$ns Res(t Bi/i$ra'hy


4/21

I+TRO2,CTIO+ A fruit is the mature ovary of a flower. A fruit contains

considerable amount of various organic acids. Citricacid is a weak organic acid found in citrus fruits. Theacid content varies in different fruits at ripe and unripestages. Therefore, unripe fruits like lemon, oranges,etc are sour in taste. At room temperature, citric acid isa white crystalline powder. It shares some propertiesof carboxylic acid. When heated above !" degreeCelsius, it decomposes to C#$ and %$#.

Chemical formula & C'%(#! )olecular weight & *$.$g +Carbon& !."-, hydrogen&.$/-, oxygen&"(.$*-0 I12AC 3A)4& $hydroxy5propane5,$,5tricarboxylic

acid


5/21

Citri% "%id in r(it

J(i%es A titration is a techni6ue to determine how much

analyte+species being analy7ed0 is present in a sample.This is done by reacting the analyte with a knownamount of titrant +species added in small increments bya buret0. In titrations, an indicator is often used todetermine the end of the reaction+endpoint0 bychanging colors.

A titration is a stoichiometric techni6ue. That is, byknowing the amunt of itrant added and the molarity of

the titrant, you calculate the number of moles of titrantthat reacted with the analyte. 3ext, a mole to moleratio is applied to find the moles of analyte.

In this experiment to estimate the amount of citricacid+analyte0 in fruit 8uices, you will add

3a#%+titrant0 to the fruit 8uice until the solution withthe phenolphthalein+indicator0 changes color to pink.9ince some of the 8uices are colored, the endpoint may

be a slightly different color.


6/21

STRUCTURE OF ACID

CH2-COOH

HO-C-COOH

CH2-COOH

USES

It is the main constituent of citrus 8uices. It is natural preservative and is also used to add an acidic +sour0taste to foods and soft drinks. It is used as anacidulous in beverages, confectionary and effervescentsalts. In biochemistry, it is important as anintermediate in the citric acid labs and therefore,

occurs in the labs as an environmentally benigncleaning agent and acts as an antioxidant and is used toad8ust p% of food.


7/21

-ey.$rds:

Volumetric analysis: a 6uantitative method ofanalysis dealing with volumes of solution and theirmeasurements.

In volumetric analysis, concentration of a solution isdetermined by allowing a known volume of a solutionto react 6uantitatively with another solution of knownconcentration.

Titration: It is the process by which the volume orconcentration of either the acid or base is determined.

Titrant: The reagent of known concentration. Titrand: The substance being titrated Normality: It is defined as the gram e6uivalents of

solute present litre of solution 3:+wt;e6uivalent weight0


8/21

#xidation state is e6ual to

. =alency of an element

$. acidity of a base.

. basicity of a acid+etc.0 Equivalence #oint: the state of a titration when

reaction is 8ust complete.

Indicator: the reagent used to locate the exactcompletion stage, i.e. end point of the reaction byshown change in its color.

It gives different colors in different medium.

It is of two types&5

. 4xternal indicator& > +fe+C300'

9elf indicator& when color of one of the titrantschanges at end point. 4g >)n/

$. Internal indicator& it is added to the solutionstaken in the conical flask.

4g. 2henolphthalein

)ethyl orange 9tarch solution )ethyl red


9/21

In the experiment sodium hydroxide is titrated againstthe fruit extract and the end point is determined when

phenolphthalein which is used as an indicator changes

color from colorless to pink.

End #oint: after the reaction between the substanceand the standard solution is practically complete, withone extra drop the indicator shows a clear usualchange in the li6uid being titrated, the stage in titrationat which this occurs is called the end point.


10/21

Titrati$n $& &r(it )(i%es

The following are performed&

3A#% v;s orange 8uice 3A#% v;s lemon 8uice 3A#% v;s sweet lime. 3A#% v;s apple 8uice.

?ix the burette vertically with the help of iron stand

and fill it with 3A#% with the help of a funnel. Take/ ml of fruit extract in the conical flask and add a fewdrops of phenolphthalein to it. #pen the tape to let

3A#% fall dropwise in the conical flask. >eep onshaking till a permanent pink color appears. 3ote thefinal reading and repeat the process till concordantreadings are obtained.


11/21

PROCE2,RE:4 Pre'arati$n $& &r(it etra%t:

Peel of the fruits and extract their juices in a

container by crushing them. Filter this juice in

another container. It should be free from seeds

and fibres.

Pre'arati$n $& 50# +610 +"OH s$(ti$n:

N!" # $%!"""&"%2'" $ # !g

(a)e *-+ fla)es of N,OH and add them to 2'"

ml of ater in a standard flas).


12/21

"PP"R"T,S

$raduated a##aratus

2ipette, burette, pipette bulb, measuring flask to

make standard solution.

$eneral a##aratus

Titration flask, beakers, gla7ed tile, glass funnel, wash bottle, burette stand

C"emical %alance &or ei!"in!

C"emicals required

9odium pellets, fruit 8uices containing citric acid+lemon 8uice, apple 8uice, sweet lime, orange 8uice,concentrated sulphuric acid, phenopthalin


13/21

OBSER7"TIO+

9olution in burette @3A#% solution

9olution in conical flask5fruit 8uices Indicator used phenolphthalein

4nd point @colourless to pink.


14/21

RIPE OR"+8E

.No. Initial /in ml0reading

Final /in ml0reading

1olumeused

!. 2 '

2. ' +

. + !!.' .'&. !!.' !&.'

NaOH olution Orange 3uice

N! # N!" N2 # 4

1!

# ml 12

# !"ml

N!1! # N212

N2 # "."N

5eight of orange 2" g

67. 5t. of Citric acid 8&."&

trength N x 67.5t."." x 8&."&

!.92 gl

In !"" ml ".!92 g

2" gm fruit contains ".!92 x!""

2"".98:


15/21

RIPE SEET IME.No. Initial /in ml0

readingFinal /in ml0

reading1olume

used

!. + 9.2 !.2

2. 9.2 !".& !.2

. !".& !!.+ !.&&. !!.+ ! !.2


N! # N!" N2 # 4

1!

# !.2ml 12

# !"ml

N!1! # N212

N2 # "."!2N

5eight of eet ;ime 2" g

67. 5t. of Citric acid 8&."&

trength N x 67.5t."."!2 x 8&."&

".*8+gl

In !"" ml "."** g

2" gm fruit contains "."** x!""

2"".+':


16/21

RIPE EMO+.No. Initial /in ml0


reading1olume

used

!. !8 &8.' ".'

2. ! !.' ".'

. 2 2 "&. ' '.' ".'


N! # N!" N2 # 4

1!

# ".'ml 12

# !"ml

N!1! # N212

N2 # "."'N

5eight of


17/21

RIPE "PPE.No. Initial /in ml0


reading1olume

used

!. ! 2.! !.!

2. 2.! .2 !.!

. .2 &.& !.2&. &.& '.' !.!


N! # N!" N2 # 4

1!

# !.!ml 12

# !"ml

N!1! # N212

N2 # "."!!N

5eight of


18/21

RES,T.No. Fruit Citric ,cid Content

!. Orange juice ".98:

2. eet ;ime juice ".+':

. ;emon juice 9.*':

&. ,==le juice ".':

Citric ,cid Content is >aximum in ;6>ON 3?IC6


19/21

PREC",TIO+S 'recautions usin! a %urette

urette should be thoroughly washed.

urette must not leak. 9top cock must be properlygreased.

urette should always be clamped vertically into the burette stand.

efore filling the burette, it must be rinsed withsmall amount to solution.

%ot solutions should not be poured into the burette.%ot li6uids make the glass expand and make errorsin measurement.

Always read the lower meniscus in case ofcolourless solution and upper meniscus in case of

coloured solutions.


20/21

'recautions usin! t"e #i#ette

2ipette should be washed thoroughly well before use. Always use the forefinger and not the thumb while

closing the upper end of the meniscus.

The solution should not be sucked too fast as it maygo into the mouth.

9olutions of poisonous substances should not besucked with the mouth. Instead use a pipette bulb or a burette.

Bo not blow off the last drop from the pipette.

'recautions "ile usin! t"e measurin! &las(

3either heat it nor add hot solutions to it. Cool thesolution to room temperature before pouring. %eadingmay change the volume of the flask.

Clean the flask before use. ast few drops of water must be added very carefully.


21/21

Bi/i$ra'hy T"is #ro)ect "as %een success&ul it" t"e material

!iven in t"e &olloin! %oo(s:

3C4DT

ab )anual of Chemistry

revised chemistry project

Documents