chemistry 11th project on ph scale

7/24/2019 Chemistry 11th Project On pH scale

1/17

BY: AKHIL GAILOT

XI E4

CHEMISTRY PROJECT


2/17

A substance with particular chemical properties incluin! turnin!litmus re" neutrali#in! al$alis" an issol%in! some metals&t'picall'" a corrosi%e or sour(tastin! li)ui o* this $in+

These substances ha%e the abilit' to prouce H,ions in %ar'in!

amount epenin! on the concentration o* the respecti%e aci+ -epenin! on concentration an aci can be istin!uishe into two

i%erse cate!ories namel'" .T/O0G A1I- an 2EAK A1I-+ A stron!aci is the aci which releases lar!e number o* H, ions on attac$ o*suitable a!ents+ Howe%er a wea$ aci is not as capable as thelatter in terms o* prouction o* H,ions+

There also man' other t'pes o* acis such as LE2I. A1I-"A//HE0I3. A1I- etc+ but these are in re*erence with the reactantthe' are reactin! with+ .uch acis are $nown as 1O03GATE BA.E+

Also there is a %er' important concept $nown as the LO2/YB/O0.TE- 1O01E5T 6O/ A1I-.+ 2e shall iscuss this later+

ACIDS


3/17

A baseis a substance that" in a)ueous solution" is slipper' to the touch"tastes bitter" chan!es the color o* inicators 8e+!+" turns re litmuspaper blue9" reacts with acis to *orm salts" an promotes certain chemicalreactions 8base catal'sis9+ Eamples o* bases are the h'roies o*the al$ali an al$aline earth metals 80aOH" 1a8OH9;" etc+9+ .uch substances

prouce h'roie ions 8OH


4/17

5ropose b' ohannes Bronste an his

companion Thomas =+ Lowr'+ Accorin! to this concept an aci is a substance

that is capable o* onatin! an H,ion an a baseis a substance that is capable o* acceptin! an H,ion" i+e acis are proton onors an bases protonacceptors+

A common eample is the issolution o* 0H>in

H;O+

0H>, H;O 0H4,, OH(

LOWRY-BRONSTED

CONCEPT OF ACIDSAND BASES


5/17

This is 'et another concept *or eplanation o*acis an bases+

This concept eals mostl' with the phenomenon

o* *ormation o* H>O,an OH?ions *or aci anbase respecti%el'+

It eals with the concept o* con@u!ate base anaci+

It states that a stron! aci has a wea$ base ana stron! base has a wea$ an %ice %ersa+

E)uation in%ol%e is as *ollows:

HA , H;O H>O,an A(

LEWIS ACIDS AND BASE


6/17

There was a pH inicator we ha use" its composition is as *ollows+

A uni%ersal inicator is t'picall' compose o* water" propan((ol" phenolphthalein soium salt" soium h'roie" meth'lre" bromoth'mol blue monosoium salt" an th'mol

blue monosoium salt+ 2e ha also use pH paper+ 2hich is a lter paper ippe an rie

in the abo%e solution +

PH INDICATOR


7/17

ItCs the re*erence scale to which the color o* the substance a*teraition o* uni%ersal inicator is compare to an the pH isconrme+

H'ronium ion concentration in molarit' is more con%enientl'

epresse on a lo!arithmic scale $nown as pH scale+ The pH o* a solution is ene as the ne!ati%e lo!arithm to base D

o* the acti%it' o* h'ro!en ion+

pH (lo!DFaH,

Its lower limit is D 8aciic9 an upper limit 4 8basic9 an neutalit' at

+

PH SCALE


8/17

The solutions !i"! #esist "!an$e in%H on &ilution o# it! t!e a&&ition o's(all a(ounts o' a"i& o# al)ali a#e"alle& B*FFER SOL*TIONS+

Buer .olutions o* $nown pH can beprepare *rom the $nowle!e o* pKa o* an

aci an pKbo* a base an b' controllin! theratio o* the salt an aci or salt an base+

2e ha%e man' t'pes o* buers we shallicuss this *urther+

B*FFER SOL*TIONS


9/17

There are two t'pes o* buer solutions"

8i9 Solutions o' sin$le substan"es,The solution o* thesalt o* a wea$ aci an a wea$ base+

Ea(%le,ammonium acetate " 1H> 1OO0H4" 0H4 10 actas a buer+

8ii9 Solutions o' Mitu#es,These are *urther o* twot'pes"

8a9 A"i&i" bu.e# ,It is the solution o* a miture o* a wea$aci an a salt o* this wea$ aci with a stron! base+

Ea(%le, 1H> 1OOH" 1H> 1OO0a+

TYPES OF B*FFER

SOL*TIONS


10/17

8b9 Basi" bu.e#,It is the solution o* a miture o* a wea$ base an a salto* this wea$ base with a stron! aci+

Ea(%le,0H4OH , 0H41l

8;9 Bu.e# a"tion: Buer action is the mechanism b' which aeH,ions or OH?ions are almost neutralise& so that pH practicall' remainsconstant+ /eser%e base o* buer neutralises the ae H,ions while thereser%e aci o* buer neutralises the ae OH?ions+

8>9 Ea(%les o' bu.e# solutions

8i9 5hthalic aci , potassium h'ro!en phthalate 8ii9 1itric aci , soium citrate+

8iii9 Boric aci , bora 8soium tetraborate9+

8i%9 1arbonic aci 8H;1O>9 , soium h'ro!en carbonate 0aH1O>+ This

s'stem is *oun in bloo an helps in maintainin! pH o* the bloo closeto +4 8pH %alue o* human bloo lies between +>J ? +4;& a chan!e in pH

b' D+; units ma' cause eath9+ 8%9 0aH>5O4, 0a>5O4 8%i9 0aH>5O4, 0a>H5O4 8%ii9 Gl'cerine , H1l

8%iii9 The pH %alue o* !astric @uice is maintaine between +J an + ueto buer s'stem+


11/17

B*FFER ACTION


12/17

AIM,- TO FIND O*T THE PH OF /ARIO*SHO*SEHOLD

ITEMS

PPARAT*S,- PH INDICATOR0 TEST T*BE0 TESTBE STAND0 BLEACH0 C*RD0 1O1*M E2TRACT0ORAN3E E2TRACT0 SHAMPOO0 /INE3AR

OMATO E2TRACT0 ANTACID0 SOAP0 WASHIN3POWDER+


13/17


14/17

SRNO+

SAMPLE %H COLORCHAN3E

NAT*RE

+ I0EGA/ 4+D /E- A1I-I1

;+ O/A0GE

EXT/A1T

+D 5EA1HY

O/A0GE

A1I-I1

>+ KOK3= EXT/A1T 4+D /E- A1I-I1

4+ TO=ATOEXT/A1T

4+D /E- A1I-I1

+ 13/- EXT/A1T +D O/A0GE A1I-I1

J+ A0TA1I- M+ TEAL BL3E BA.I1+ BLEA1H D+D LIGHT BL3E BA.I1

M+ .OA5 +D AN3/E BL3E BA.I1

+ .HA=5OO +D 0O 1HA0GE 0E3T/AL

D+ 2A.HI0G

5O2-E/

+D AN3/E BL3E BA.I1

OBSER/ATIONS


15/17

I ha%e obtaine this in*ormation *romthe *ollowin! truste sources:

+ 2i$ipeia an 01E/T 5A/T 86O/-E6I0ITIO0.9

;+ 1HE=I.T/Y E//O/LE.. olume An G/B 0E2 E/A 1HE=I.T/Y olume 86O/ EX5LA0ATIO0.9

>+ 1hemistr' Auillar'8 6O/ /EA-I0GO6 pH9

BIBLIO3RAPHY


16/17

6irstl'" I woul li$e to than$ m' 1hemistr'Teacher " =iss Aashima *or !i%in! us sucha woner*ul topic to o such an ama#in!

pro@ect+.econl'" I woul li$e to than$ m' *amil' *or

helpin! me in !atherin! in*ormation anhelpin! in the presentation o* this pro@ect+

AC1NOWLED3EMENT


17/17

chemistry 11th project on ph scale

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