Acid/BaseChemistry

Acid/BaseChemistry

Portland Community College Staff*

Version42-0137-00-01

Lab Report Assistant

Thisdocumentisnotmeanttobeasubstitute foraformallaboratoryreport.TheLabReport Assistantissimplyasummaryoftheexperiment’squestions,diagramsifneeded,anddatatables that shouldbeaddressedinaformallabreport. Theintentistofacilitatestudents’writing oflab reports by providing this informationin an editable filewhich can be sent to an instructor.

Observations Incolumns3 and4, recordthe colorandintensityseen. In columns5 and6, determine ifthe substanceisanacidorabase,andifthesubstanceisionic.Forthelastcolumn,determinewhich chemical species is actingas an acid or base.

Data Table 1: Acids and Bases Actingin Water
Well	Substance	1dropBTB	Plus1dropof substance	Acidor base (Q1)	Ionic? Y/N (Q2)	Species actingas acidor base (Q3)
1	NaHCO3
2	CH3COOH
3	HCL
4	Na2CO3
5	H2SO4
6	CH3COONa
7	NaOH
8	HNO3
9	NaHSO4
10	NH3
11	H3PO4
12	NaH2PO4
13	Na2HPO4
14	Na3PO4
15	NaHSO3

Data Table 2: Following Acid/Base neutralizationreactions
Well #	1Dropof Each	Observation	+2Drops Acid	Observation	+2Drops Base	Observation
1	BPB+ NaOH		HCl		NaOH
2	BPB+ NaOH		H2SO4		NaOH
3	BPB+ NaOH		CH3COOH		NaOH
4	BPB+ NaOH		H3PO4		NaOH
5	BPB+ Ca(OH)2		HCl		Ca(OH)2
6	BPB+ Ca(OH)2		H2SO4		Ca(OH)2
7	BPB+ Ca(OH)2		CH3COOH		Ca(OH)2
8	BPB+ Ca(OH)2		H3PO4		Ca(OH)2
9	BPB+ NH3		HCl		NH3
10	BPB+ NH3		H2SO4		NH3
11	BPB+ NH3		CH3COOH		NH3
12	BPB+ NH3		H3PO4		NH3

Please note here if any of the other starting materials is other than a clear, colorless solution.

Data Table 3: Investigating Odor as a Means of IndicatingNeutralization.
Substance(s)	Odor
2Dropsof HClinWell#1
1Dropof Ammoniaon Swab
SwabwithAmmonia& HCl

Data Table 4: Investigating Evaporationas a Means of Indicating a Neutralization Reaction.
ReactionMixture	Observation(When Wet)	Observation(When Dry)
HCl + NaOH
CH3COOH + NH3
HNO3+ NaOH

PART5:Mini-Experiments

1. UseBTBtoclassifyfourhouseholdproductsasacidicorbasic.Possiblesubstancestotest includehomecleaningproducts, glasscleaner,liquiddetergent,bleach, softdrinks,liquid from food items, etc. Remember to:

a. Hypothesis (What you think will happen and why) or purpose:

b. Method used to test your hypothesis:

c. DataandObservationsPutyourdataandobservationsinthespace below.Youcaninclude pictures that you “draw.”

d. Conclusions

2. Find onecommon,highlycoloredsubstancethatcanbeusedasanacid-baseindicator.

Possiblesubstancesinclude fruit/vegetablejuiceorproducts, inks,foodcoloring,flower

petals,etc.Ifusingfreshfruit,veggies,orflowers,crushthesubstancewithalittlewateror

rubbingalcoholto extractthecoloredpigments.Ifredcabbageis available,itmakesasuperb

acid-baseindicator.Thenuseafewdropsofthecoloredextractastheindicator.Testfour

more household products using the freshly made acid-base indicator. Remember to:

a. State a hypothesis or purpose.

b. State the testingmethod.

c. Usethepreparedindicatortotestfoursubstancesknowntobeacidsorbasesfromeither the LabPaq or home materials and record results.

d. State conclusions in terms of the hypothesis or purpose.

Questions

A. ReviewthesubstancesusedinPart1.Determinewhethereachsubstancecontainsanacidor a base based on the BTB results. Place answers to this questionin column 6 of Data Table 1.

B. ReviewtheresponsestoQuestion3.Theanionthatisproducedinthedissociationofthe compoundgoesonto reactwiththe water.Identifytheanion productineachreaction.Placethe formulasfor these species intocolumn7 ofData Table1. If the substance isnotionicandthus does not dissociate, then list the substance in column 7, just as it appears in column 1.

-

C. Foreachionicspecies inDataTable1,writetheequationshowingthedissociationofthe compound in water. Hint: there’s one for each line provided below.

+

a. NaHCO3àNa

+ HCO3

Reviewtheresponses toQuestion 3.Theanionthatisproducedinthedissociation ofthe compoundgoesonto reactwiththe water.Identifytheanion productineachreaction.Placethe formulasfor these species intocolumn7 ofData Table1. If the substance isnotionicandthus does not dissociate, then list the substance in column 7, just as it appears in column 1.

D. Write the reaction of each acid or base the substance listed in column 7 with water.

Acids: Bases:

a) HCO-+ H-OH àHCO

+ OH-

3 2 3

1. What is produced in each and every reactionof an acid with water?

2. What is produced in each and every reactionof a base with water?

E. Reviewtheresults inDataTable2.Foreachreactionmixture,writethereactionequation describing the acid/base neutralizationreaction:

2) 2NaOH + H2SO4 à2H2O+ Na2SO4

F. Definetheterm“neutralization”andprovideanexampleofaneutralizationequation.Listthe three ways used in this lab to detected neutralization.

G. Definethe term “salt,” and provide an example.

H. ReviewDataTable3.Whathappenedwhenthetwochemicalsweremixed?Whatindicates that conclusion? What reaction took place?

I. ReviewDataTable4.Whathappenedwhenthesolution mixturesontheglassslide were heated? Describe the process that took place.

J. InPart4,forHCl+NaOH,whatisleftontheslide afterheating?Providetheformula.Whatis the common name of this substance?