QUANTITATIVE ANALYSIS

CHE 251

 

RETURN TO THE CHEMISTRY LAB PREP PAGE



EXPERIMENTS
 
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51



 

EXP. 1: PREPARATION OF 0.1 N SOLUTIONS OF HYDROCHLORIC ACID AND SODIUM HYDROXIDE

 
 

HYDROCHLORIC ACID

glass-stoppered bottle

distilled water

graduated cylinder or measuring pipet

0.1 N HCl diluted to 1L

SODIUM HYDROXIDE (Carbonate Free)

0.1 N NaOH: 6 to 7 ml of a 1:1 soln NaOH + DH2O diluted to 1L with DH2O

0.1 N NaOH: Dissolve 50 g NaOH in 50 ml DH2O in rubber-stoppered erlenmeyer flask. Allow to stand then filter using Gooch Crucible or decant to remove the sodium carbonate precipitate. Dilute soln. to 1L.

0.1 N NaOH: Dissolve 4 to 4.5 g sodium hydroxide in 400 ml DH2O and add 10 ml barium chloride soln. Allow to stand overnight then decant and dilute soln. to 1L.

Do not use glass-stoppered bottles for storage purposes.

Return to Contents Section
 
 

EXP. 2: DETERMINATION OF THE RELATIVE CONCENTRATIONS OF THE HYDROCHLORIC ACID AND SODIUM HYDROXIDE SOLUTIONS

 

(2) Burets

hydrochloric acid solution, 35 to 40mL

Sodium Hydroxide solution 

250-mL Erlenmeyer flask

2 drops phenolphthalein indicator or alternative below

ALTERNATIVES:

phenolphthalein: 2 g phenolphthalein/ 95% ethanol

bromthymol blue: 0.1 g bromthymol blue + 8 ml 0.02M NaOH dilute to 100 ml w/ distilled water

methyl red: 1 g sodium salt of methyl red/ 1 L distilled water

50 mL distilled water 

Graduated cylinder

Calculator

Return to Contents Section
 
 

EXP. 3: STANDARDIZATION OF SODIUM HYDROXIDE SOLUTION WITH POTASSIUM ACID PTHALATE

 

4 to 5g pure potassium acid phthalate

Electronic balance

weighing bottle

oven at 110C

dessicator

three numbered erlenmeyer flasks w/ 0.7 to 0.9g potas. acid phthalate

50mL distilled water for each erlenmeyer flask

Graduated cylinder

2 drops phenolphtalein per flask

Buret 

Sodium hydroxide solution

hydrochloric acid solution

Calculator

Return to Contents Section
 
 

 EXP. 4: STANDARDIZATION OF THE HYDROCHLORIC ACID SOLUTION WITH SODIUM CARBONATE

 

Hydrochloric Acid solution

TRIS OR TRAM (AKA tris (hydroxymethyl) aminomethane) or pure sodium carbonate: three samples of 0.20 to 0.25 g

NOTE: analytical-grade sodium carbonate @ 99% dry 1/2 hr @ 270 to 300C in oven AND/OR TRIS @ 99.95% dry 1 hr @ 100 to 105C in oven: Prep FRESH 

Electric balance

(3) Erlenmeyer flask w/ previously dried sodium carbonate

50mL distilled water 

2 drops methyl red or methyl orange

Preparation of methyl orange (pH = 4): 1 g potassium acid phthalate in 100 ml distilled water

1 g Potassium acid phthalate + 100 ml distilled water; pH=4

2 drops methyl orange

Hydrochloric acid solution

Sodium hydroxide 

(3) Erlenmeyer flask w/ 0.4 to 0.5 g previously dried TRIS 

50mL distilled water

Bromocresol green: 0.1 gt bromocresol green + 0.1 M NaOH then dilute to 100 ml

Sodium hydroxide solution

Calculator

Return to Contents Section
 
 

EXP. 5: DETERMINATION OF THE PURITY OF POTASSIUM ACID PHTHALATE

 

Solid acid sample: unkown w/ potassium acid phthalate or sulfamic acid; three samples of 0.7 to 0.9 g

Calculator

weighing bottle

Electric balance

oven @ 110C

Desiccator for cooling samples

(3) Erlenmeyer flask w/ unknown samples

75 to 100mL distilled water (boil water for 5 min to remove CO2)

2 drops Phenolpthtalein indicator

standard sodium hydroxide solution

30 to 45 ml of 0.1N base for titration

Return to Contents Section
 
 

EXP. 6: DETERMINATION OF ACETIC ACID CONTENT OF VINEGAR

 

Calculator

Pipet, 10 to 50 ml

25 ml vinegar

250 volumetric flask

Erlenmeyer flask

50mL water

2 drops Phenolpthalein indicator

standard base  (0.1N base for titration)

Return to Contents Section
 
 

EXP. 7: DETERMINATION OF THE ALKALINITY OF SODA ASH

 

balance

250mL beaker

dried unknown, 1g

125mL distilled water

funnel

250mL volumetric flask

Pipet, 10 to 50 ml

Erlenmeyer flask

2 drops of methyl red or methyl orange

standard acid (30 to 45 ml of 0.1 N acid for titration)

Calculator

Na2CO3

Return to Contents Section
 
 

EXP. 8: TITRATIONS IN NONAQUEOUS MEDIA

 

0.1 N HCIO4: add 4.3 ml of 72% perchloric acid to 150 ml glacial acetic acid, mix well, add 10 ml of acetic anhydride, and allow the solution to stand for 30 min. Dilute to 500 ml with glacial acetic acid and allow the solution to cool to room temperature.

0.1N Sodium acetate: dissolve 4.1 g of anhydrous sodium acetate in glacial acetic acid and dilute to 500 ml with the acid.

(2) Burets

35 to 40mL perchloric acid

2 drops of methyl violet indicator

Electronic Balance

0.5 to 0.6g pure potassium acid phtalate

glacial acetic acid

(3) Erlenmeyer flask

hot plate or bunsen burner

three samples of unknown substance (amine or amino acid)

Desiccator

2 drops methyl violet indicator

50mL acetic acid

50 ml pipet

Return to Contents Section
 
 

EXP. 9: PREPARATION OF 0.1 M SOLUTIONS OF SILVER NITRATE AND POTASSIUM THIOCYANATE

 

Electronic balance

0.1M silver nitrate: 8.5 g silver nitrate dilute to 500 ml w/ dist. water   NOTE:  preparesilver nitrate in dark or brown-glass bottle; no light Beaker

0.1 M thiocyanate solution: 4.9 g potassium thiocyanate diluted to 500 ml with distilled water.

Calculator

Return to Contents Section
 
 

EXP.10: STANDARDIZATION OF SILVER NITRATE AND POTASSIUM THIOCYANATE

 

Electronic balance

MOHR METHOD:

three samples of prure, dry Sodium chloride

NOTE: use potassium chloride or sodium chloride  1.1 to 1.2 g sodium chloride or 1.5 to 1.6 g potassium chloride diluted to 250 ml in a volumetric flask

250 mL erlenmeyer flask (3 needed)

2 mL of 0.1M Potassium Chromate Solution: 19.4 g/1L

Silver Nitrate

indicator blank: 2 ml indicator/100 ml + a few 10th of a gram of chloride-free calcium carbonate

OR FAJANS METHOD:

three samples pure, dry sodium chloride; 0.2 to 0.25 g each

three 250 ml erlenmeyer flasks

standard NaCl solution: sample + 50 ml distilled water + 10 drops dichlorofluorescein indicator + 0.1 g dextrin

Calculator

NOTE: Dry salts @ 120C for ~2hr

25 ml standard silver nitrate solution

250 ml erlenmeyer flask

5 ml 1: 1 nitric acid

1 ml iron (III) alum solution (indicator): sat'd solution of iron (III) in 1 M nitric acid

Return to Contents Section
 

EXP. 11: DETERMINATION OF CHLORIDE

 

MOHR METHOD:

Electronic balance

three samples of dried material

(3) 250mL Erlenmeyer flask 

50mL distilled water

2mL 0.1M Potassium Chromate Solution

standard silver nitrate solution (see exp 10)

Calculator

buret

FAJAN METHOD:

balance

three samples of dried material

three 250 ml erlenmeyer flasks

50 ml distilled water 

ten drops of dichlorofluorescein indicator

0.1 g dextrin

buret

litmus paper

one drop phenolphthalein

dilute nitric acid (1 ml to 150 ml distilled water)

0.1 N sodium hydroxide

VOLHARD METHOD:

balance 

three samples

three 250 ml erlenmeyer flasks

50 ml distilled water

5 ml 1: 1 nitric acid (see wxp 10)

standard silver nitrate solution (see exp 10)

buret

1 to 2 ml nitrobenzene or alternative

alternative = 1% nitric acid solution; potassium thiocyanate, and gooch or sintered-glass cruible

rubber stopper for flasks; 3

1 ml iron(III) slum indicator (see exp 10)

standard potassium thiocyanate solution

Return to Contents Section
 
 

EXP. 12: DETERMINATION OF SILVER IN AN ALLOY

 

Electronic balance

three samples of Sliver alloy

three 250mL Erlenmeyer flask

15mL of 1: 1 nitric acid

50 ml volumetric flask

hot plate

1 ml iron(III) alum indicator (see exp 10)

standard thiocyanate solution

buret

Calculator

Return to Contents Section
 
 

EXP. 13: PREPARATION AND STANDARDIZATION OF SODIUM EDTA SOLUTION

 

Calculator

Electronic balance

4g disodium dihydrogen EDTA dihydrate

0.1 g MgCl2. 6H2O

400 ml beaker

1 liter bottle

few drops of 0.1 M sodium hydroxide solution

standard calcium chloride solution: 0.4 g primary CaCl dried @ 100C diluted to 500ml then add drops 1:1 hydrochloric acid.

500mL volumetric flask

pipet, 10 to 50 ml

250 ml erlenmeyer flask

5 ml ammonia-ammonium chloride buffer solution: 6.75 g ammonium chloride in 57 ml conc. ammonia then dilute to 100 ml; pH>10 five drops eriochrome black T indicator: 0.5 g reagent grade eriochrome black T in 100 ml alcohol.

alternative indicator: calmagite: 0.05 g indicator in 100 ml water ; 4 drops

Return to Contents Section
 
 

EXP. 14: DETERMINATION OF CALCIUM BY EDTA TITRATION

 

unknown sample containing 350 to 400mg of CaCO3

Electronic balance

400mL beaker

5 to 10 mL 1:1 hydrochloric acid

50mL distilled water

Hot plate

2 drops methyl red indicator (see exp 2)

6 M NaOH

500mL volumetric flask

pipet, 10 to 50 ml

250 Erlenmeyer flask

5 ml ammonia-ammonium chloride buffer solution (see exp 13)

five drops eriochrome black T indicator (see exp 13)

Return to Contents Section
 
 

EXP. 15: DETERMINATION OF THE TOTAL HARDNESS OF WATER

 

water sample

pipet

(3) 250mzl Erlenmeyer flask

1.0 mL buffer solution (see exp 13)

5 drops indicator solution (see exp 13)

standard EDTA solution 

Calculator

Return to Contents Section
 
 

EXP. 16: DETERMINATION OF CALCIUM IN CALCIUM GLUCONATE

 

0.025M standard solution EDTA

10g Na2H2Y.2H2O

NaOH pellets

standard calcium chloride solution (see exp 13; see note below); NOTE: use instead 1.0 g primary standard grade calcium carbonate 

 zl ium gluconate bablets

stainless steel spatula

glass rod

oven to dry powder at 100C for 1hr

balance

0.4 g sample

(3) 250 ml Erlenmeyer flasks

50mL distilled water

hot plate

5 ml Ammonia-Ammonium chloride buffer (see exp 13)

5 drops Eriochrome black T indicator (see exp 13)

standard EDTA solution

buret

Calculator

Return to Contents Section
 
 

EXP. 17: DETERMINATION OF CHLORINE IN A SOLUBLE CHLORIDE

 

Oven (1 to 2 hr @ 100 to 120C)

(3) porous-bottom filtering crucibles (sintered glass or porous porcelain) of medium porosity

porus filtering discs

concentrated nitric acid

oven @ 100 to 150C

Electronic balance

three potions dried samples; 0.5 to 0.7 g

three 250mL beaker

100 - 150mL water

1 mL nitric acid

0.1 M silver nitrate solution (25 to 20 mg AgNO3/ml)

hot plate w/ stirrer

Silver nitrate solution

beaker

three watch glasses

three 25 ml potions of 0.01 M nitric acid: about two drops of concentrated nitric acid in 100 ml water

wash bottle

wash solution

filter

rubber policeman

drop hydrochloric acid

small glass hooks

dessicator

unknown solid: portion of 0.5 to 0.7

Return to Contents Section
 
 

EXP. 18: DETERMINATION OF SULFUR IN A SOLUBLE SULFATE

 

Oven @ 100 to 120C

Electronic balance

three potions of 0.5 to 0.8 g sample

200mL distilled water

1mL concentrated hydrochloric acid

5% barium chloride: 5g BaCl2.2H2O in 100 ml water

Beaker

graduated cylinder

hot plate

dropper or pasteur pipet

watch glass

thermometer (must measure between 80 to 90C)

steam bath, on hot plate, or using low flame from bunsen burner

fine porous porcelain filtering crucible or funnel w/filter paper

filter paper: slow type, i.e. whatman no. 42 (preferred) or no. 40

(3) crucibles and lids of porous porcelain (or ordinary porcelain w/ filter paperz0

rubber policeman

drop silver nitrate solution

Test Tube

Tirrill burner 

concentrated sulfuric acid

Meker burner

Return to Contents Section
 
 

EXP. 19: DETERMINATION OF IRON IN AN OXIDE ORE

 

Electronic balance

three samples of 0.5 g each of dried iron oxide unknown 

OR

Solutions containing CaCO3 dissolved in Hcl may be used as uninowns. However then use 400 ml beakers and pipets

250mL beaker

20mL 1:1 hydrochloric acid

watch glass

hot plate

wash bottle

10mL saturated bromine water

1 to 2 ml of conc. nitric acid

fast filter paper (i.e. whatman no. 41)

400mL beaker

dilute hydrochloric acid solution

1:2 ammonium hydroxide solution 

25mL of 0.1 M ammonium nitrate wash soln. (8 or 10 g NH4NO3/L)

Funnel

50 ml of 1:10 hydrochloric acid solution

Pipet

hot 0.1 M ammonium nitrate wash solution

 Rubber policeman

balance

Ashless filter paper

meker burner (prefered) or tirrill burner

dessicator

Return to Contents Section
 
 

EXP. 20: GRAVIMETRIC DETERMINATION OF CALCIUM

 

three samples of unknown; 0.5 to 0.7 g each (solutions containing CaCO3 dissolved in HCl may be used as unknowns)

400 ml beaker

75mL water

10mL 1:3 hydrochloric acid 

hot plate with stirrer or glass rod

150mL distilled water

AMMONIUM OXALATE SOLUTION: (two 10 ml portions)

30 ml of this solution: 1 g of ammonium oxalate in 30 ml of water containing 2 ml of concentrated hydrochloric acid. Also add three drops of methyl red indicator

1g Ammonium oxalate

3 drops methyl red indicator

2mL hydrochloric acid

30 ml water

15g sp;od urea

Cold 0.1% Ammonium oxalate solution 

Ashless filter paper of medium porosity (i.e., whatman no. 40)

IF CALCIUM OXALATE MONOHYDRATE USED:

sintered-glass crucible of medium porosity and filtered w/suction

oven@ 105C for 1 hr

porcelain crucible with lid

clay triangle 

Tirril burner

muffle furnace at 1000C for 30 min.

Dessiccator

Return to Contents Section
 
 

EXP. 21: DETERMINATION OF NICKEL IN STEEL

 

three samples of 1 g of Steel (sample should contain about 25 to 35 mg of nickel)

balance

400mL beaker

60mL 1:1 hydrochloric acid

10mL 1:1 nitric acid

hot plate

200 ml distilled water

25mL of 20% Tartaric acid solution: dissolve 25 g of fartaric acid in 100 ml distilled water; filter before use if not clear

concentrated ammonia

Filter paper

hot solution containing a little ammonia and ammonium chloride

hydrochloric acid 

thermometer that reads 70C

20 ml of 1% solution of dimethylglyoxime in alcohol: dissolve 10 g of dimethylgloxime in 1 L of 95% ethanol

Fritted-glass or gooch crucible

cold water

oven @ 110 to 120C

Return to Contents Section
 
 

EXP. 22: OXIDATION-REDUCTION TITRATIONS: PREPARTION OF A 0.1 N POTASSIUM PERMANGANATE SOLUTION

 

0.1 N good grade potassuim permanganate (3.2 g/L)

balance

250 ml beaker

1100 ml water

glass rod

large beaker

glass-stoppered bottle, ~1L size

Cerium (IV)Sulfate

Potassiumdichromate 

Iodine

Sodium Thiosulfate

250mL beaker

Filter

Sintered-glass crucible using suction

labeled glass-stoppered bottle

Return to Contents Section
 
 

EXP. 23: STANDARDIZATION OF POTASSIUM PERMANGANATE SOLUTION

 

SODIUM OXALATE FOWLER-BRIGHT METHOD

balance 

three samples of 0.25 to 0.3 g each of dried salt (sodium oxalate)

500mL Erlenmeyer flasks

dilute Sulfuric Acid: 12.5 ml conc. acid diluted to 250 ml (550 ml/student)

250 ml volumetric flask

hot plate with stirrer or glass rod

Permanganate (35 to 40 ml)

thermometer

OR---

MCBRIDE METHOD:

balance

three samples of 0.25 to 0.3g each of dried sodium oxalate

three 250 ml erlenmeyer flasks

three potions of 75 ml 1.5 N sulfuric acid (20 ml conc. sulfuric acid to 400 ml water)

hot plate

thermometer (80 to 90C)

100 ml 1.5 N sulfuric acid

permanganate solution in dropper bottle

ARSENIC (III) OXIDE:

balance 

three portions of 0.2g each of pure arsenic (III) oxide, previously dried

oven 

three 250 ml erlenmeyer flasks

30 ml cool NaOH soln (20 g sodium hydroxide in 80 ml water)

glass rod or stirring rod

100 ml distilled water

10 ml conc. hydrochloric acid

 0.0025 M potassium iodide solution (catalyst) in dropper bottle = 0.4 g in 1 L water (OR ALTERNATIVE: potassium iodate or monochloride

buret, 50 ml

IRON WIRE:

three samples of 0.2 g each of pure iron wire, free of rust

balance 

three 150 ml beakers

20 ml of 1:1 hydrochloric acid

steam bath or low flame

tin(II) chloride as reducing agent

Return to Contents Section
 
 

EXP. 24: DETERMINATION OF AN OXALATE

 

Electronic weight

three portions dried material comtaining sodium oxalate, 1 g

250 and 500mL Erlenmeyer flask

250mL Water

Dilute Sulfuric acid, 250 ml (12.5 ml H2SO4 to 250 ml water)

hot plate

sulfuric acid, 1.5 N (20 ml H2SO4 to 400 ml water)

buret

Return to Contents Section
 
 

EXP. 25: DETERMINATION OF HYDROGEN PEROXIDE

 

Pipet, 25 ml

Peroxide solution, 0.1 N, 25 ml

250-mL volumetric flask

250-mL Erlenmeyer flask

conc. Sulfuric acid, 5 ml

75mL water

Permanganate solution

buret

Return to Contents Section
 
 

EXP. 26: DETERMINATION OF HYDROGEN PEROXIDE

 

3 samples of Iron ore

electronic balance

three 150-mL beakers

Hydrochloric acid, conc. 10 ml

distilled water

Watch glasses, 3 needed

Steam bath or hot plate or wire gauze

fume hood (when ore dissolves)

mortar & pestle

porcelein crucible & cover

tin(III) chloride: Dissolve 113 g SnCl2.H2O (free of iron) in 250 ml conc. HCl, then add pieces of mossy tin, and dilute to 1 L with distilled water

potassium permanganate crystals

filter paper

potassium pyrosulfate, 5 g

bunsen burner

1:1 hydrochloric acid, 25 ml

hot plate

saturated mercury(II) chloride solution, 20 ml

erlenmeyer flasks, 500 ml

zimmermann-reinhardt solution, 25 ml: Dissolved 70 g MnSO4 in 500 ml DH2O and add slowly, with stirring, 110 ml conc. #2504 and 200ml 85% phosphoric acid. Dilute to 1 L.

blank: 10 ml DH2O + 10 ml conc. HCl

Return to Contents Section
 
 

EXP.27: DETERMINTION OF OXYGEN IN PYROLUSITE

 

three samples of 0.5 g finely ground and dried ore (1.5 g/student

three 250 ml erlenmeyer flasks (3/student)

3 portions of 0.25 g pure sodium oxalate (0.75 g/student)

100mL of sulfuric acid per flask (10 ml H2SSO4/ 100 ml H2O) (300 ml/student)

Steam bath(hot plate) or bursen burner

thermometer

watch glass, 3 needed

rinse/squeeze bottle with distilled water

standard permanganate

Electronic balance

Calculator

buret

Return to Contents Section
 
 

EXP. 28: PREPARATION OF A 0.1 N CERIUM (lV) SOLUTION

 

CERIUM (IV) SULFATE

33g Cerium (IV) Sulfate or 53g Ce(SO4)2.2(NH4)2SO4. 2H2O

glass rod

sulfuric acid solution (add 28 ml H2SO4 to 500 ml H2O)

clean bottle, size = >1L

Trip balance

*OR* 21 g cerium (IV) oxide in 1500 ml beaker. Add hot sulfuric acid soln. (78 ml conc. H2SOr to 300 ml distilled water. Then dilute to 1L.

CERIUM (IV) AMMONIUM NITRATE

electronic balance

54.83 g primary standard grad Cerium (IV) ammonium nitrate

1-liter beaker

56 ml conc. sulfuric acid

distilled water, 700 ml

1 L volumetric flask

magnetic stirrer/hot plate w/stirrer or glass rod

Return to Contents Section
 
 

EXP. 29: STANDARDIZATION OF THE CERIUM (lV) SOLUTION

 

ARSENIC (III) OXIDE

Electronic balance

3 portions of 0.2 pure Arsenic (III) oxide (previously dried in oven)

Oven

500-mL Erlenmeyer flask, 3 needed

10 ml of cool sodium hydroxide solution (20 g NaOH + 80 ml H2O)

Stirrer or glass rod

100mL water

25mL of 1:10 sulfuric acid

2 drops 0.01M osmium tetroxide solution (catalyst) (dissolve 0.125 g of OsO4 in 50 ml of 0.1 N H2SO4)

2 drops ferroin (AKA iron(II) 1,10-phenanthroline sulfate) (indicator) (dissolve 1.5 g of 1, 10-phenanthroline monohydrate, C12H8N2.H2O in 100 ml of 0.025 M iron (II) sulfate) PREPARE FRESH

buret

IRON WIRE

Calculator

three samples of 0.2g pure iron wire, free of rust (0.6 g/student)

150-mL beaker (3/student)

20ml of 1:1 hydrochloric acid (60 ml/student)

Steam bath (hot plate) or bunsen burner

Tin(II) Chloride

20 mL Saturated mercury(II)chloride solution 

500mL Erlenmeyer flask

10mL concentrated hydrochloric acid

2 drops of ferroin indicator

Return to Contents Section
 
 

EXP. 30: DETERMINATION OF IRON IN AN ORE

 

Electronic balance

Iron ore (see exp. 26)

Tin(II) chloride (see exp. 26)

20mL saturated mercury (II) chloride solution

500mL Erlenmeyer flask

1 M HCl, 300 ml

2 drops of ferroin indicator

standard cerium (IV) solution 

buret

Calculator

Return to Contents Section
 
 

EXP. 31: PREPARATION AND STANDARDIZATION OF A 0.1 n POTASSIUM DICHROMATE SOLUTION

 

Electronic balance

4.9g of pure potassium dichromate which has been dried in oven

400-mL beaker

1-liter volumetric flask

iron wire samples (see exp. 23)

Iron(III) ion

Tin(II) chloride (see exp. 26)

500-mL Erlenmeyer flask

250-mL water

5mL concentrated sulfuric acid

5ml of 85% phosphoric acid

 eight (8) drops of sodium diphenylaminesulfonate indicator (dissolve 0.3 g sodium slt in 100 ml water OR 0.3 g hot water + exess 0.1 M sodium sulfate solution; let soln stand until barium sulfate settles; filter or decant soln. from precipitate)

filter paper

buret

Calculator

Oven

Return to Contents Section
 
 

EXP. 32: DETERMINATION OF IRON IN AN ORE USING DICHROMATE

 

Electronic balance

Tin(II)chloride (see exp, 26)

20mL saturated mercury (II) chloride solution 

500mL Erlenmeyer flask

250mL distilled water

5mL concentrated sulfuric acid

5 ml 85% phosphoric acid

8 drops sodium diphenylaminesulfonate indicator (see exp. 31)

dichromate solution (see exp. 31)

Calculator

buret

wash bottle

Return to Contents Section
 
 

EXP.33: PREPARATION AND STANDARDIZATION OF 0.1N IODINE SOLUTION

 

Trip balance

12.7g reagent-grade iodine: place 20 g potassium iodide in a large weighing bottle, dissolve in 10 ml water, weigh bottle and add 6.4 g iodine and stopper bottle. Transfer soln to 500 ml vol, flask, dilute to  mark, mix and place in glass stoppered bottle.

250-mL beaker

40g potassium iodide

25mL water

Iodide 

BROWN glass-stoppered bottle for storing IKI soln.

ARSENITE SOLUTION

Reagent-grade 1.25g arsenic(III) oxide (to dry place in dessicator over sulfuric acid for 12 hrs)

3g sodium hydroxide

10mL water

50mL water

2 drops phenolpthalein indicator

1:1 hydrochloric acid, 1 ml

250 ml volumetric flask

25 ml pitet

250mL Erlenmeyer flask

50mL water

sodium bicarbonate, small potion

~6g sodium bicarbonate (buffer)

5mL starch indicator: 2 g soluble starch, 25 ml water, 500ml boiling water. Cool then add 1 g boric acid. Store in glass-stoppered bottle.

*OR* 5 ml starch indicator : prepare 4:1 urea: starch in beaker, ground in motor and use small scoopful in place of starch soln.

Return to Contents Section
 
 

EXP. 34: DETERMINATION OF PURITY OF ARSENIC(lll)OXIDE

 

Electronic balance

three samples of unknown of 3 to 15% arsenic (III) oxide

500-mL Erlenmeyer flask, 3 needed

distilled water

1g sodium hydroxide

bunsen burner, hot plate

Desiccator

2 drops phenolphthalein indicator

1:1 hydrochloric acid

~6 g sodium bicarbonate

150mL water

5mL starch solution

buret

stirring rod

Calculator

Return to Contents Section
 
 

EXP. 35: DETERMINATION OF VITAMIN C

 

Electronic balance

(3) 100mg Vitamin C tablets

250mL Erlenmeyer flask, 3 needed

150 ml distilled water

5mL starch indicator (see exp.32)

buret

stirring rod

Calculator

Return to Contents Section

 

EXP. 36: PREPARATION AND STANDARDIZATION OF A 0.1 N SODIUM THIOSULFATE SOLUTION

 

25g Sodium thiosulfate pentahydrate crystals

1liter water

hot plate or bunsen burner

0.2 Sodium carbonate

POTASSIUM DICHROMATE

Electronic balance

three portions of 0.2g DRY potassium dichromate

three 500mL Erlenmeyer flask

100mL water

4mL conc. sulfuric acid

2g sodium carbonate

5mL water 5 g potassium iodide (see exp. 33)

Water glass

5ml starch solution

COPPER

Calculator

three portions 0.2 to 0.25 g clean copper wire or foil

three 250-mL Erlenmeyer flask

5mL 1:1 nitric acid

Steam bath(hot plate) or bunsen burner

25mL water

5mL urea solution (1 g in 20 ml water)

1:3 Ammonia

5mL glacial acetic acid

3g potassium iodide

buret

Watch glass

Thiosulfate solution

5mL starch solution

2g potassium thiocyanate

Calculator

timer or stop watch

thermometer

Return to Contents Section
 
 

EXP.37: DETERMINATION OF COPPER IN AN ORE

 
 

Electronic balance

three sample of finely ground, dried ore

250 mL beaker, 3 needed

5mL conc. hydrochloric acid

10mL conc. nitric acid

Watch glass

bunsen burner

10mL 1:1 sulfuric acid

use fume hood

25mL water

5mL saturated bromine water

filter paper

Burner

1:3 ammonium hydroxide

5mL glacial acetic acid

2g Ammonium acid fluoride (chemical will etch glass of storage container)

3g potassium iodide

10mL water

5mL starch solution (see exp. 36)

2g potassium thiocyanate

Calculator

filter paper

NOTE: Dissolve copper oxide commercial unknown by warming 10 to 15 min. in 15 ml of 1:2 sulfuric acid

Return to Contents Section
 
 

EXP. 38: IODEMETRIC DETERMINATION OF HYDROGEN PEROXIDE

 

25mL peroxide solution

250-mL volumetric flask

250-mL Erlenmeyer flask

1:6 (~6N) sulfuric acid, 8 ml

3g potassium iodide

10mL water

3 drops 3% ammonium molybdate solution

5mL starch solution

buret

Calculator

Electric balance

Return to Contents Section
 
 

EXP. 39: DETERMINATION OF BLEACHING POWER BY IODOMETRY

 

Bleach: clorox & purex (2 ml) contain sodium hypochlorite or clorox II & snowy bleach (0.7 to 0.8 g)

0.1 N thiosulfate (titrant)

250-mL Erlenmeyer flask

75mL distilled water

3g of KI

8mL 1:6 sulfuric acid

3 drops of 3% ammonium moylbdate solution

5mL starch solution

thermometer

hot plate

buret

Return to Contents Section
 
 

EXP. 40: DETERMINATION OF MAGANESE IN STEEL

 

SPECTRAL - TRANSMITTANCE CURVE

sample of steel of known manganese content

50mL 1L3 nitric acid

flask

bunsen burner or hot plate

1g Ammonium persulfate

Drops of sodium sulfite or sulfurous acid

10 mL of 85% phosphoric acid

0.5 g potassium periodate

250mL volumetric flask

spectrophotometer: 440 to 700 nm , readings at 20 nm intervals initial and 5nm intervals at the end.

BEER'S LAW CHECK

100mL beaker or Erlenmeyer flask, 4 needed

distilled water

graph paper (student will provide)

rulers (students will provide)

calculator

labels

ANALYSIS OF SAMPLE