Arun Chem Project

Jawahar Navodaya vidyalaya,Kiltampalem

Investigatory project on chemistry

On the topic:Comparative study of commercial antacids

Guided by: done by:

J.Sameena (P.G.T. chemistry) P.Arun sai kumar

Class:XII, roll:4662908

Certificate This is to certify that ________________, a bonafide student of Jawahar Navodaya Vidyalaya,Kiltampalem has completed his chemistry investigatory project on ”COMPARITIVE STUDY OF COMMERCIAL ANTACIDS” under the guidance of his/her chemistry teacher Sri J.Sameena and the work done by him is original .

Signature of the lecturer incharge signature of the examiner

Acknowledgements On the forefront I would like to offer my heartfelt prayers to the almighty and the omnipresent who owed me everything in my life and to whom I am highly indebted.

Next in my thanks giving list I would like to include my parents who gave me birth and helped me in every step of my life.

I would use this opportunity to to convey my heart felt gratitude to our principal Sri.M.V.Subba Rao garu who permitted to do this project and extended his helping hand in every aspect in completing this project.

I would like to convey my sincere thanks to Smt.J. Sameena (P.G.T.chemistry) who guided us through the project and gave us the ample support to complete this project technically and mentally.

I would like to extend my gratitude to Sri.Yella Rao(lab asst.) Garu who gave his valuable support in completing this project.

Last but not the least I would like to thank my friends who motivated me and extend their valuable helping hand in completing this project

Lastly I would like to thank all the people who directly or indirectly involved in this project.

ACKNOWLEDGEMENT (i) ANTACIDS 1 ACTION MECHANISM 1 INDICATIONS 1 SIDE EFFECTS 1 - 2 SOME MORE SIDE EFFECTS 2 - 3 HYPERACIDITY 3 - 4 SOME FAMOUS ANTACID BRANDS 4 - 5 DRUG NAMES 5 SOME COMMONLY USED ANTACIDS6ALUMINIUM HYDROXIDE 6 -7MAGNESIUM HYDROXIDE 8 – 9CALCIUM CARBONATE 10 – 13SODIUM BICARBONATE 14 – 16BISMUTH SUBSALICYLATE 17 –18 INVESTIGATORY EXPERIMENT 19 – 21 BIBLOGRAPHY (ii)

ANTACIDSAn Antacid is any substance, generally a base or basic salt, whichneutralizes stomach acidity. They are used to relieve acidindigestion, upset stomach, sour stomach, and heartburn.ACTION MECHANISMAntacids perform a neutralization reaction, i.e. they buffer gastric acid,raising the pH to reduce acidity in the stomach. When gastric hydrochloricacid reaches the nerves in the gastrointestinal mucosa, they signal pain tothe central nervous system. This happens when these nerves are exposed,as in peptic ulcers. The gastric acid may also reach ulcers in the esophagusor the duodenum.

Other mechanisms may contribute, such as the effect of aluminium ionsinhibiting smooth muscle cell contraction and delaying gastric emptying.INDICATIONSAntacids are taken by mouth to relieve heartburn, the major symptom ofgastro esophageal reflux disease, or acid indigestion. Treatment withantacids alone is symptomatic and only justified for minor symptoms. Pepticulcers may require H2-receptor antagonists or proton pump inhibitors.The utility of many combinations of antacids is not clear, although thecombination of magnesium and aluminium salts may prevent alteration ofbowel habits.SIDE EFFECTSExcess calcium from supplements, fortified food and high-calcium diets, cancause the milk-alkali syndrome, which has serious toxicity and can be fatal.In 1915, Bertram Sippy introduced the "Sippy regimen" of hourly ingestion ofmilk and cream, the gradual addition of eggs and cooked cereal, for 10 days,combined with alkaline powders, which provided symptomatic relief forpeptic ulcer disease. Over the next several decades, the Sippy regimenresulted in renal failure, alkalosis, and hypercalemia, mostly in men withpeptic ulcer disease. These adverse effects were reversed when the regimenstopped, but it was fatal in some patients with protracted vomiting. Milk alkalisyndrome declined in men after effective treatments were developed forpeptic ulcer disease. But during the past 15 years, it has been reported inwomen taking calcium supplements above the recommended range of 1200

to 1500 mg daily, for prevention and treatment of osteoporosis, and isexacerbated by dehydration. Calcium has been added to over-the-counterproducts, which contributes to inadvertent excessive intake.The New England Journal of Medicine reported a typical case of a womanwho arrived in the emergency department vomiting and altered mentalstatus, writhing in pain. She had consumed large quantities of chewableantacid tablets containing calcium carbonate (Tums). She graduallyrecovered.[1]Compounds containing calcium may also increase calcium output in theurine, which might be associated with kidney stones.[2] Calcium salts maycause constipation.Other adverse effects from antacids include:1. Carbonate : Regular high doses may cause alkalosis, which in turn mayresult in altered excretion of other drugs, and kidney stones. A chemicalreaction between the carbonate and hydrochloric acid may producecarbon dioxide gas. This causes gastric distension which may not be welltolerated. Carbon dioxide formation can also lead to headaches anddecreased muscle flexibility.2. Aluminum hydroxide : May lead to the formation of insoluble aluminiumphosphate-complexes, with a risk for hypophosphatemia andosteomalacia. Although aluminium has a low gastrointestinal absorption,accumulation may occur in the presence of renal insufficiency. Aluminiumcontainingdrugs may cause constipation.3. Magnesium hydroxide : Has laxative properties. Magnesium mayaccumulate in patients with renal failure leading to hypermagnesemia,with cardiovascular and neurological complications. See Milk of

magnesia.4. Sodium : Increased intake of sodium may be deleterious for arterialhypertension, heart failure and many renal diseases.SOME MORE SIDE EFFECTSFortunately, because acid reflux is such a common problem, antacids areamong the medicines available and free of side effects for most people. Sideeffects from antacids vary depending on individual and other medicationsthey may be taking at the time. Those who experience side effects mostcommonly suffer from changes in bowel functions, such as diarrhea,constipation, or flatulence.Although reactions to any drug may vary from person to person, generallythose medications that contain aluminum or calcium are the likeliest to causeconstipation, those that contain magnesium are the likeliest to causediarrhea. Some products combine these ingredients, which essentiallycancels them out, to forestall unpleasant side effects.In general, people with kidney problems should probably not take antacidsas this can sometimes cause a condition known as alkalosis. In other people,side effects may occur if substances such as salt, sugar, or aspirin, areadded to a particular medication. As with all medications, always carefullyread the product label on the package and check with your doctor orpharmacist if you have any question about potential drug interactions or sideeffects.Some side effects, such as constipation and diarrhea, are fairly obvious.Other more serious side effects, such as stomach or intestinal; bleeding, canbe more difficult to recognize. In general, any sign of blood in the stool or the

presence of vomiting is a danger sign and should be brought to theimmediate attention of a physician.If your symptoms persist for more than 10 days to two weeks while you areusing the medication, you should stop taking it and consult your doctor.Persistent symptoms may indicate that you have more a serious problemthan occasional acid reflux. Pregnant or nursing baby should always consultyour doctor before taking this medication. Generally, you should not givethese medications to children under the age of 12 unless under the adviceand supervision of your doctor or the package label has indicated that theproduct is safe for young children. Constant use of antacids leads to acondition called acid rebound where the stomach begins to over secrete acidin order to make up for the quantity that is being neutralized.HYPERACIDITY, CAUSE FOR INTAKE OF ANTACIDSHyperacidity or acid dyspepsia simply means increase of acidity in thestomach. The human stomach secretes hydrochloric acid which is necessaryfor the digestion of food. When the stomach contains an excessive amount ofhydrochloric acid, then the condition is called as hyperacidity or aciddyspepsia.Sometimes, hyperacidity is confused for a simple bellyache. This is becausepeople with hyperacidity usually generally get pains in their stomachs withsimilar symptoms as bellyaches. This confusion is more rampant in childrenwho cannot differentiate between different kinds of stomach ailments.However, hyperacidity can be found out with the sour belching and aftertasteof the already eaten food in the mouth.

The prime medical factors of hyperacidity or acid dyspepsia are as follows :(i) Stomach Ulcers: Ulcers in the stomach are one of the prime causes ofhyperacidity. Once this is diagnosed, the treatment will be done by thesurgical removal of the stomach ulcers.(ii) Acid Reflux Disease: Some people have a gastric disorder called as theacid reflux disease. In this condition, the acids of the stomach, i.e. gastricacids or hydrochloric acid, get refluxed up to the food pipe, which isbiologically called as the esophagus. When this happens, it builds up thelevel of acidity in the stomach.(iii) Stomach Cancers: Stomach cancers can also cause hyperacidity as oneof their symptoms. This is a very rare case, but the mortality rate is quitehigh. Hence, a hyperacidity that lasts more than two weeks must beimmediately shown to the doctor and got checked for any cancer. A timelydiagnosis can enable complete treatment of the disease.SYMPTOMS OF HYPERACIDITYHyperacidity symptoms are observed a couple of hours after eating, whenthe food has been digested and still excess acids are left within the stomach.At this stage, the following symptoms are seen:-1. A typical feeling of restlessness2. Feeling of nausea (wanting to throw up) and actual vomiting3. Sour belching with an aftertaste of the already-eaten food4. Stiffness in the stomach, which is called as atonic dyspepsia5. Lack of desire for any other type of food6. Indigestion7. ConstipationINTERACTIONSAltered pH or complex formation may alter the bioavailability of other drugs,such as tetracycline. Urinary excretion of certain drugs may also be affected.

PROBLEMS WITH REDUCED STOMACH ACIDITYReduced stomach acidity may result in an impaired ability to digest andabsorb certain nutrients, such as iron and the B vitamins. Since the low pH ofthe stomach normally kills ingested bacteria, antacids increase thevulnerability to infection. It could also result in reduced bioavailability ofsome drugs. For example, the bioavailability of ketoconazole (antifungal) isreduced at high intragastric pH (low acid content).SOME FAMOUS ANTACID BRANDS1. Alka-Seltzer – NaHCO3 and/or KHCO32. Equate – Al(OH)3 and Mg(OH)23. Gaviscon – Al(OH)34. Maalox (liquid) – Al(OH)3 and Mg(OH)25. Maalox (tablet) – CaCO36. Milk of Magnesia – Mg(OH)27. Pepto-Bismol – HOC6H4COO8. Pepto-Bismol Children’s – CaCO39. Rolaids – CaCO3 and Mg(OH)210. Tums – CaCO311. MylantaDRUG NAMESSome drugs used as antacids are :1. Aluminium hydroxide2. Magnesium hydroxide3. Calcium carbonate4. Sodium bicarbonate5. Bismuth subsalicylate6. Histamine7. Cimetidine8. Ranitidine9. Omeprazole10. Lansoprazole

SOME IMPORTANT COMMONLY USEDANTACIDS1. ALUMINIUM HYDROXIDE

Aluminium hydroxide, Al(OH)3, Alum, is the most stable form of aluminium innormal conditions. It is found in nature as the mineral gibbsite (also known ashydrargillite) and its three, much more rare, polymorphs: bayerite, doyleiteand nordstrandite. Closely related are aluminium oxide hydroxide, AlO(OH),and aluminium oxide, Al2O3, differing only by loss of water. These compoundstogether are the major components of the aluminium ore bauxite. Freshlyprecipitated aluminium hydroxide forms gels, which is the basis forapplication of aluminium salts as flocculants in water purification. This gelcrystallizes with time. Aluminium hydroxide gels can be dehydrated (e.g.,with the utility of water-miscible non-aqueous solvents like ethanol) to forman amorphous aluminium hydroxide powder, which is readily soluble inacids. Heat-dried aluminium hydroxide powder is known as activatedalumina and is used in gas purification, as a catalyst support and anabrasive.PRODUCTIONBauxites are heated in pressure vessels with sodium hydroxide solution at150–200 °C through which aluminium is dissolved as aluminate (Bayerprocess). After separation of ferruginous residue (red mud) by filtering, puregibbsite is precipitated when the liquid is cooled and seeded with finegrained aluminium hydroxide. The aluminium hydroxide is further calcined togive alumina, which may be smelted in the Hall-Héroult process in order toproduce aluminium.CHEMISTRYGibbsite has a typical metal hydroxide structure with hydrogen bonds. It is

built up of double layers of hydroxyl groups with aluminium ions occupyingtwo-thirds of the octahedral holes between the two layers.Aluminium hydroxide is amphoteric. It dissolves in acid, forming Al(H2O)63+(hexaaquaaluminate) or its hydrolysis products. It also dissolves in strongalkali, forming Al(OH)4- (tetrahydroxoaluminate).PHARMACOLOGYPharmacologically, this compound is used as an antacid under names suchas Alu-Cap, Aludrox or Pepsamar. The hydroxide reacts with excess acid inthe stomach, reducing its acidity. This decrease of acidity of the contents ofthe stomach may in turn help to relieve the symptoms of ulcers, heartburn ordyspepsia. It can also cause constipation and is therefore often used withmagnesium hydroxide or magnesium carbonate, which havecounterbalancing laxative effects. This compound is also used to controlphosphate (phosphorus) levels in the blood of people suffering from kidneyfailure.Aluminium hydroxide, alum, is included as an adjuvant in some vaccines(e.g., Alhydrogel, Anthrax Vaccine), since it appears to contribute toinduction of a good antibody (Th2) response. Its pharmacological action isnot known. However, it has little capacity to stimulate cellular (Th1) immuneresponses, important for protection against many pathogens.Because the brain lesions found in Alzheimer's disease sometimes containtraces of aluminium, there is concern that consumption of excess aluminiumcompounds may cause or contribute to the development of this and otherneurodegenerative diseases. However, multiple epidemiological studies

have found no connection between exposure to aluminium and neurologicaldisorders.In addition, elevated aluminium levels in blood, resulting from kidney dialysiswith well water containing high aluminium, may result in dementia that issimilar to but probably different from that of Alzheimer's disease. However,this hypothesis is controversial.In 2007, tests with mice of the anthrax vaccine using aluminium hydroxideadjuvant were reported as resulting in adverse neuropathy symptoms.USE AS A FIRE RETARDANTAluminium hydroxide also finds use as a fire retardant filler for polymerapplications in a similar way to magnesium hydroxide and hydromagnesite. Itdecomposes at about 180 °C giving off water vapour.2. MAGNESIUM HYDROXIDEMagnesium hydroxide is an inorganic compound with the chemical formulaMg(OH)2. As a suspension in water, it is often called milk of magnesiabecause of its milk-like appearance. The solid mineral form of magnesiumhydroxide is known as brucite.Magnesium hydroxide is common component of antacids and laxatives; itinterferes with the absorption of folic acid and iron. Magnesium hydroxidehas low solubility in water, with a Ksp of 1.5×10−11; all of magnesium hydroxidethat does dissolve does dissociate. Since the dissociation of this smallamount of dissolved magnesium hydroxide is complete, magnesiumhydroxide is considered a strong base.HISTORYIn 1829, Sir James Murray used a fluid magnesia preparation of his own

design to treat the Lord Lieutenant of Ireland, the Marquis of Anglesey. Thiswas so successful (advertised in Australia and approved by the RoyalCollege of Surgeons in 1838) that he was appointed resident physician toAnglesey and two subsequent Lords Lieutenants, and knighted. His fluidmagnesia product was patented two years after his death in 1873.The term milk of magnesia was first used for a white-colored, aqueous, mildlyalkaline suspension of magnesium hydroxide formulated at about 8%w/v byCharles Henry Phillips in 1880 and sold under the brand name Phillips' Milk ofMagnesia for medicinal usage.Although the name may at some point have been owned by GlaxoSmithKline,USPTO registrations show "Milk of Magnesia" to be registered to Bayer, and"Phillips' Milk of Magnesia" to Sterling Drug. In the UK, the non-brand(generic) name of "Milk of Magnesia" and "Phillips' Milk of Magnesia" is"Cream of Magnesia" (Magnesium Hydroxide Mixture, BP).PREPARATIONMagnesium hydroxide can be precipitated by the metathesis reactionbetween magnesium salts and sodium, potassium, or ammonium hydroxide:Mg2+ (aq.) + 2 OH− (aq.) → Mg(OH)2 (s)USESSuspensions of magnesium hydroxide in water (milk of magnesia) are usedas an antacid to neutralize stomach acid, and a laxative. The diarrhea causedby magnesium hydroxide carries away much of the body's supply ofpotassium, and failure to take extra potassium may lead to muscle cramps.Magnesium hydroxide is also used as an antiperspirant armpit deodorant.

Milk of magnesia is useful against canker sores (aphthous ulcer) when usedtopically.Milk of magnesia is sold for medical use as chewable tablets, capsules, andas liquids having various added flavors. It is used as an antacid, though moremodern formulations combine the antimotility effects of equal concentrationsof aluminum hydroxide to avoid unwanted laxative effects.Magnesium hydroxide powder is used industrially as a non-hazardous alkalito neutralise acidic wastewaters. It also takes part in the Biorock method ofbuilding artificial reefs.Solid magnesium hydroxide has also smoke suppressing and fire retardingproperties. This is due to the endothermic decomposition it undergoes at 332°C (630 °F) :Mg(OH)2 → MgO + H2OBIOLOGICAL METABOLISMWhen the patient drinks the milk of magnesia, the suspension enters thestomach. Depending on how much was taken, one of two possible outcomeswill occur.As an antacid, milk of magnesia is dosed at approximately 0.5–1.5g in adultsand works by simple neutralization, where the hydroxide ions from theMg(OH)2 combine with acidic H+ ions produced in the form of hydrochloricacid by parietal cells in the stomach to produce water.Only a small amount of the magnesium from milk of magnesia is usuallyabsorbed from a person's intestine (unless the person is deficient inmagnesium). However, magnesium is mainly excreted by the kidneys solongterm, daily consumption of milk of magnesia by someone suffering from

renal failure could lead in theory to hypermagnesemia.

3.CALCIUMCAR ONATE

Calciumcarbonate sachemcalcompoundwiththechemicalformula CaCO3. Itisacommonsubstancefoundinrockinallpartsofthewo rld,and isthemaincomponentofshells ofmarineorganisms,snails,pearls,and eggshells. Calciumcarbonateis theactiveingredientinagriculturallime, andisusuallytheprincipalcauseofhardwater. Itiscommonlyused medicinallyasacalciumsupple mentorasanantacid,butexcessive consumptioncanbehazardous.

CHEMICALPROPERTIESCalciumcarbonatesharesthetypicalpropertiesofothercarbonate s.Notably:

itreactswithstrongacids, releasingcarbondioxide:CaCO

3(s) +2HCl

(aq)

→ CaCl

2(aq) +CO

2(g) +H

2O

(l)

itreleasescarbondioxideonheating(toabove840°Cinthecaseof CaCO3),toformcalciumoxide,commonlycalledquicklime,with reactionenthalpy178kJ/mole:

CaCO3 → CaO+CO2

Calciumcarbonatewillreactwithwaterthatissaturatedwithcarbondioxide toformthesolublecalciumbicarbonate.

CaCO3 +CO2 +H2O → Ca(HCO3)2

Thisreactionisimportantintheerosionofcomarbnaterocks,forming caverns,andleadstohardwaterinmanyregi ns.

PREPARATIONGEOLOGY Thevastmajorityofcalciumcarbonateusedinindustryisextractedby miningorquarrying. Purecalc umcarbonate(e.g. forfoodorpharmaceutical use),canbeproducedfromapurequarriedsource(usuallymarble).

Alternatively,calciumoxde spreparedbycalciningcrudecalcium carbonate. Waterisaddedtogvecalciumhydroxide,andcarbondioxideis passedthroughthissolutontoprecpitatethedesiredcalciumcarbonate, referredtointheindustryasprecptatedcalciumcarbonate(PCC):

CaCO3 → CaO+CO2CaO+H2O → Ca(OH)2

Ca(OH)2 +CO2 → a O3 +H2O

Carbonateisfoundfrequentlyingeologicsettings. Itisfoundasa polymorph. Apolymorphisamineralwiththesamechemicalformulabut differentchemicalstructure. Aragonite,calcite,limestone,chalk,marble, travertine,tufa,andothersallhaveCaCO3 astheirformulabuteachhasa slightlydifferentchemicalstructure. Calcite,ascalciumcarbonateis commonlyreferredtoingeologyiscommonlytalkedaboutinmarine settings. Calciteistypicallyfoundaroundthewarmtropicenvironments. Thisisduetoitschemistryandproperties. Calciteisabletoprecipitatein warmershallowenvironmentsthanitdoesundercolderenvironments becausewarmerenvironmentsdonotfavourthedissolutionofCO2. Thisis analogoustoCO2 beingdissolvedinsoda. Whenyoutakethecapoffofasodabottle,theCO2 rushesout. Asthesodawarmsup,carbondioxideis released. Thissameprinciplecanbeappliedtocalciteintheocean. Cold watercarbonatesdoexistathigherlatitudesbuthaveaveryslowgrowth rate.

Intropicsettings,thewatersarewarmandclear. Consequently,youwillsee manymorecoralinthisenvironmentthanyouwouldtowardsthepoles wherethewatersarecold. Calciumcarbonatecontributorssuchascorals, algae,andmicroorganismsaretypicallyfoundinshallowwater environmentsbecauseasfilterfeederstheyrequiresunlighttoproduce calciumcarbonate.

USESIndustrialapplications

Themainuseofcalciumcarbonateisinthe nstructionindustry,eitherasa buildingmaterialinitsownright(e.g. marble) rlimestoneaggregatefor roadbuildingorasaningredientofcement rasthestartingmaterialforthe preparationofbuilder'slimebyburninginakiln.

Calciumcarbonateisalsousedinthepurifi ati nofironfromironoreina blastfurnace. Calciumcarbonate scalcinedinsitutogivecalciumoxide, whichformsaslagwithvarous mpuritiespresent,andseparatesfromthe purifiediron.

Calciumcarbonateiswidelyusedasanextenderinpaints,inparticularmatteemulsionpaintwheretypcally30%byweightofthepaintiseitherchalkormarble.

Calciumcarbonateisalsowdelyusedasafillerinplastics. Sometypical examplesincludearound15to20%loadingofchalkinunplasticized polyvinylchloride(uPV )dranppe,5to15%loadingofstearatecoated chalkormarbleinuPV wndowprofile. PVCcablescanusecalcium carbonateatloadingsofupto70phr(partsperhundredpartsofresin)to improvemechanicalpropertes(tensilestrengthandelongation)and electricalproperties(volumeresstvity). Polypropylenecompoundsare oftenfilledwithcalciumcarbonatetoincreaserigidity,arequirementthat becomesimportantathighusetemperatures. Italsoroutinelyusedasafiller inthermosettingresins(SheetandBulkmouldingcompounds)andhasalso beenmixedwithABS,andotheringredients,toformsometypesof compressionmolded"clay"Pokerchips.

Finegroundcalciumcarbonateisanessentialingredientinthemicroporous filmusedinbabies'diapersandsomebuildingfilmsastheporesare nucleatedaroundthecalciumcarbonateparticlesduringthemanufactureof thefilmbybiaxialstretching.

Calciumcarbonateisknownaswhitinginceramics/glazingapplications, whereitisusedasacommoningredientformanyglazesinitswhite powderedform. Whenaglazecontainingthismaterialisfiredinakiln,the whitingactsasafluxmaterialintheglaze.

ItisusedinswimmingpoolsasapHcorrectorformaintainingalkalinity "buffer"tooffsettheacidicpropertiesofthedisinfectantagent.

Itiscommonlycalledchalkasithastraditionallybeenamajorcomponentof blackboardchalk. Modernmanufacturedchalkisnowmostlygypsum, hydratedcalciumsulfateCaSO4·2H2O.

HEALTHANDDIETARYAPPLICATIONScom

Calciumcarbonateiswidelyusedmedicinallyasaninexpensivedietary calciumsupplementorantacid. Itmaybeusedasaphosphatebinderforthe treatmentofhyperphosphatemia(primarilyinpatientswithchronicrenal failure). Itisalsousedinthepharmaceuticalindustryasaninertfillerfor tabletsandotherpharmaceuticals.

Calciumcarbonateisused ntheproduction ft othpasteandisalsousedin homeopathyasoneoftheconsttutonalre edies. Also,ithasseena resurgenceasafoodpreservatveandcolorretainer,whenusedinorwith productssuchasorganicapplesorfood.

Excesscalciumfromsupplements,fortifiedfoodandhigh-calciumdiets,can causethe"milkalkalisyndrome,"whichhasserioustoxicityandcanbefatal. In1915,BertramSippyintroducedthe"Sippyregimen"ofhourlyingestionof milkandcream,andthegradualadditionofeggsandcookedcereal,for10 days,combinedwithalkalnepowders,whichprovidedsymptomaticrelieffor pepticulcerdisease. Overthenextseveraldecades,theSippyregimen resultedinrenalfalure,alkaloss,andhypercalemia,mostlyinmenwith pepticulcerdisease. Theseadverseeffectswerereversedwhentheregimen stopped,butitwasfatalinsomepatentswithprotractedvomiting. Milkalkali syndromedeclinedinmenaftereffectivetreatmentsforpepticulcerdisease.

AformoffoodadditiveisdesignatedasE170. Itisusedinsomesoymilk productsasasourceofdietarycalcium;onestudysuggeststhatcalcium carbonatemightbeasbioavailableasthecalciumincow'smilk.

.SODIUMBICARBONATE

Sodiumbicarbonate orsod umhydrogencarbonate isthechemical compoundwiththeformulaNaH O3. odiumbicarbonateisawhite solidthat iscrystallinebutoftenappearsa safinepowder. Itcanbeusedto experimentandisnotverydangerous. Ithasaslightalkalinetaste resemblingthatofwashingsoda (sodiumcarbonate). Itisacomponentofthe mineralnatronandisfounddssolvedinmanymineralsprings. The natural mineralformisknownasnahcol te. Itisfoundinitsdissolvedform inbile, whereitservestoneutralzethe acdityofthehydrochloricacidpro ducedby thestomach,andisexcreted ntotheduodenumofthesmallintestineviathe bileduct. Itisalsoproducedart fcally. Sinceithaslongbeenknownand swidelyused,thesalthasmany related namessuchasbakingsoda,breadsoda, cookingsoda, bicarbonateofsoda. Colloquially,itsnameisshortenedto sodiumbicarb, bicarbsoda,orsimply bicarb. Thewordsaleratus,from Latinsalæratusmeaning"aeratedsalt", waswidelyusedinthe19thcenturyforbothsodiumbicarbonatean d potassiumbicarbonate. Theter mhasnowfallenoutofcommonusa ge.

HISTORYTheancientEgyptiansusednaturaldepositsofnatron,amixtureconsisting mostlyofsodiumcarbonatedecahydrateandsodiumbicarbonate. The natronwasusedasacleansingagentlikesoap.

In1791,aFrenchchemist,NicolasLeblanc,producedsodiumbicarbonate asweknowittoday. In1846twoNewYorkbakers,JohnDwightandAustin Church,establishedthefirstfactorytodevelopbakingsodafromsodium carbonateandcarbondioxide.

PRODUCTIONNaHCO3 ismainlypreparedbytheSolvaypr ess,whichisthereactionof calciumcarbonate,sodiumchloride,ammonia,andcarbondioxideinwater. Itisproducedonthescaleofabout100,000t n/year(asof2001).[2]

NaHCO3 maybeobtainedbythereactionof arb ndioxidewithanaqueous solutionofsodiumhydroxide. Theinitialrea ti nproducessodiumcarbonate:

CO2 +2NaOH →Na 2O3+H2O

Furtheradditionofcarbondoxdeproducessodiumbicarbonate,whichatsufficientlyhighconcentratonwllprecipitateoutofsolution:

Na2CO3 +CO2 +H2O → 2NaH O3

Commercialquantitiesofbakngsodaarealsoproducedbyasimilar method:sodaash,mined ntheformoftheoretrona,isdissolvedinwater andtreatedwithcarbondoxde. odiumbicarbonateprecipitatesasasolid fromthismethod:

Na2CO3 +CO2 +H2O → 2NaH O3

CHEMISTRYSodiumbicarbonateisanamphotericcompound. Aqueoussolutionsare mildlyalkalineduetotheformationofcarbonicacidandhydroxideion:

HCO−3+H2O → H2CO3 +OH−

Sodiumbicarbonatecanbeusedasawashtoremoveanyacidicimpurities froma"crude"liquid,producingapurersample. Reactionofsodium bicarbonateandanacidtogiveasaltandcarbonicacid,whichreadily decomposestocarbondioxideandwater:

NaHCO3 +HCl → NaCl+H2CO3H2CO3 → H2O+CO2 (g)

Sodiumbicarbonatereactswithaceticacid(CH3COOH)toformsodium acetate:

NaHCO3 +CH3COOH →CH3COONa+H2O+CO2 (g)

Sodiumbicarbonatereactswithbasessuchassodiumhydroxidetoform carbonates:

NaHCO3 +NaOH→ Na2CO3 +H2O

Sodiumbicarbonatereactswithcarboxylgrco

mupsinproteinstogiveabrisk

effervescencefromtheformationofCO2

..Thisreactionisusedtotestforthepresenceofcarboxylic

groupsinprotein

APPLICATIONSSodiumbicarbonateisprimarilyusedinc king(baking)whereitreacts withothercomponentstoreleasecarbondi xide,thathelpsdough"rise". Theacidiccompoundsthatinducethisrea ti nincludephosphates,cream oftartar,lemonjuice,yogurt,buttermilk,c a,vinegar,etc. Sodium bicarbonatecanbesubst tutedforbakingp wderprovidedsufficientacid reagentisalsoaddedtotherecpe.[3] Manyformsofbakingpowdercontain sodiumbicarbonatecombnedwthoneormoreacidicphosphates (especiallygood)orcreamoftartar. Itcanalsobeusedforsofteningpeas(⅛ tsp. perpintofwaterandbrngtoboilforonehour)

Manylaboratorieskeepabottleofsodiumbicarbonatepowderwithineasy reach,becausesodiumbcarbonateisamphoteric,reactingwithacidsand bases. Furthermore,asit srelatvelyinnocuousinmostsituations,thereis noharminusingexcesssodumbcarbonate. Lastly,sodiumbicarbonate powdermaybeusedtosmotherasmallfire.

Sodiumbicarbonate sused nanaqueoussolutionasanantacidtakenorally totreatacidindigestionandheartburn. Itmayalsobeusedinanoralformto treatchronicformsofmetabolicacidosissuchaschronicrenalfailureand renaltubularacidosis. Sodiumbicarbonatemayalsobeusefulinurinary alkalinizationforthetreatmentofaspirinoverdoseanduricacidrenal stones.

Sodiumbicarbonatecanbeusedtoextinguishsmallgreaseorelectricalfires bybeingpouredordumpedoverthefire. However,itshouldnotbepoured ordumpedontofiresindeepfryersasitmaycausethegreasetosplatter. SodiumbicarbonateisusedinBCdrychemicalfireextinguishersasan alternativetothemorecorrosiveammoniumphosphateinABC extinguishers. Thealkal inatureof sodium bi carbon ate makes it the onlydry chemicalagent,besidesPurple-K,thatwasusedinlargescalefire suppressionsystemsinstalledin commercialkitchens. Because itcan act as analkali,theagenthasamildsaponificationeffectonhotgrease,w hich formsasmotheringsoapyfoam. Drychemicalshavesincefallenoutoffavor forkitchenfiresastheyhaveno coolingeffectcomparedtotheextremely effectivewetchemicalagentsspecificallydesignedforsuchhazar ds.

5.BISMUTHSUBSALICYLATE

Bismuthsubsalicylate,w thachemcalformulaC7H5BiO4,isadrug usedtocom

treatnausea,heartburn, ndgeston,upsetstomach,diarrhea,and other.

temporarydiscomfortsofthestomachandgastrointestinaltract. Commonlyknownaspinkbismuth,it stheactveingredientinpopularmedications suchasPepto-Bismolandmodern(since2003)Kaopectate.

PHARMACOLOGYAsaderivativeofsalicylicacd, bsmuthsalicylatedisplaysanti-inflammatory

actionandalsoactsasanantac d. ADVERSEEFFE TSAND ONTRAINDICATIONSTherearesomeadverseeffects. Itcancauseablacktongueandblackstools insomeusersofthedrug,when itcombineswithtraceamountsof sulfurin salivaandthegastrointestinaltract. Thisdiscolorationistemporaryand harmless.

Someoftherisksofsalicylismcanapplytotheuseofbismuthsubsalicylate.

Childrenshouldnottakemedicationwithbismuthsub

salicylatewhile recoveringfrominfluenzaorchickenpox,asepidemiologicevidenc epoints toanassociationbetweentheuseofsalicylate-containingmedications duringcertainviralinfectionsandtheonsetofReye'ssyndrome. Forthe samereason,itistypicallyreco mmendedthatnursingmothersnot usemedication containin gbismuth subsalicylate( such asPepto-Bismol)because small amounts of the medication are excreted in breast milk and posea theoreticalriskofReye'ssyndrometonursingchildren.

RADIOACTIVITYWhilebismuthistechnicallyradioactive,itshalflifeissolong,ontheorderofhundredsofbillionsofyears,thatitsradioactivitypresentsabsolutelyno threatunderallmedicalandotherordinarypurp ses.

DECOMPOSITIONBismuthsubsalicyclateistheonlyactiveingredientinanoverthecountermedicationthatwillactuallyleaveashinymetalslagbehind.

INVESTIGATORYEXPERIMENT

OBJECTIVE:Toanalysethegivensamplesofcommercialantacidsbydeterminingthe amountofhydrochloricacidtheycanneutralize.

REQUIREMENTS: comBurettes,pipettes,titrationflasks,measuringflasks,beakers,weightbox, fractionalweights,sodiumhydroxide,sodiu arbonate,hydrochloricacid, phenolphthalein.

PROCEDURE:1. Prepare1litreofapproximately HCls

lutionbydiluting10mlofthe concentratedacidforonelitre

2. Similarly,make1litreofapproximately NaOHsolutionby dissolving4.0gofNaOHtoprepareonelitreofsolution.

3. Prepare Na2CO3 solut onbyweighingexactly1.325gofanhydrous

sodiumcarbonateandthendssolvingitinwatertoprepareexactly 0.25litres(250ml)ofsoluton.

4. StandardizetheHClsolutonbytitratingitagainstthestandardNa2CO3 solutionusingmethylorangeasindicator.

5. Similarly,standardizeNaOHsolutionbytitratingitagainststandardized HClsolutionusingphenolphthaleinasindicator.

6. Powderthevarioussamplesofantacidtabletsandweigh1.0gofeach.7.

AddaspecificvolumeofstandardisedHCltoeachoftheweighed sampleistaken nconcalflasks. Theacidshouldbeinslightexcess,so thatitcanneutralizeallthealkalinecomponentofthetablet.

8.

Add2dropsofphenolphthaleinandwarmtheflasktillmostofpowder dissolves. Filterofftheinsolublematerial.

9. TitratethissolutionagainstthestandardisedNaOHsolution,tilla permanentpinkishtingeisobtained. Repeatthisexperimentwith differentantacids.

OBSERVATIONSANDCALCULATIONS :StandardisationofHClsolution:

Volumeof Na2CO3 solutiontaken=20.0ml

SNo. Burettereadings Volumeofof acidusedobs. Initial Final

1. 0ml15.0ml 15.0ml

2. 0ml15.1ml 15.1ml

3. 0ml15.0ml 15.0ml

4. 0ml15.0ml 15.0ml

5. 0ml15.0ml 15.0ml

Concordantvolume=15.0mlApplyingnormalityequation,

N1V1 =N2V2N1 *15.0= *20

NormalityofHCl,N1 = = 0.133N

.StandardisationofNaOHsolut on:

VolumeofthegivenNaOHsolutontaken=20.0ml

SNo. Burettereadings Volumeofof acdusedobs. Initial Final

1. 0ml26.5ml 26.5ml

2. 0ml26.8ml 26.8ml

3. 0ml26.6ml 26.6ml

4. 0ml26.6ml 26.6ml

5. 0ml26.6ml 26.6ml

Concordantvolume=26.6mlApplyingnormalityequati

on,′1

′1 =

′2

′2

0.133*26.6= ′2 *20

.NormalityofNaOH, ′2 =

= 0.176N

Analysisofantacidtablet:

Weightofantacidtabletpowder=1.0g

VolumeofHClsolutionadded=20.0mlAntacid Vol. OfNaOH Vol. OfHClsoln.

soln. Usedto Usedtoneutralise neutralise1.0gofunusedHCl antacidmatter

1. Gelusil 12.1ml 12.0ml2. Digene 16.0ml 16.2ml3. Aludrox 19.3ml 18.9ml4. Logas 24.3ml 24.4ml5. Ranitidine 21.4ml 21.7ml6. Ocid20 22.7ml 21.9ml

CONCLUSION :Theantacidwhichhasmaximumvolume fHClisusedforneutralizingi.e.OCID20ismoreeffective.

THISPROJECTISMADEWITHTHEHELPOF FOLLOWINGLINKS:1. WEBSITES :

www.wikipedia.org www.google.com www.yahoo.com www.pharmaceutical-drugmanufacturers.com

2.BOOKS: Comprehensive

practcalManualforclassXII

Pradeep’sNew ourseChemistry

NCERTClassXIIPartII