Qualitative analysis of anions essay

The objective of this experiment was going to use qualitative analysis to look for the chemical features of four regarded anions by systemic confirmatory testing. The chemical qualities observed may be used to identify an unknown sample. Sulphuric acidity was to be added to a carbonate solution and a great effervescent response would what is presence of carbonate anions. Another test of carbonate solution was going to be reacted with hydrochloric acid plus the gaseous merchandise was to end up being reacted having a suspended drop of ba (symbol) carbonate.

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Arsenic intoxication clouding inside the droplet would also confirm the presence of carbonate anions. Silver nitrate was to become added to chloride solution and the formation of the white precipitate, silver chloride, would confirm the presence of chloride anions. Ammonium hydroxide would be put into dissolve area of the precipitate.

The resultant supernatant solution was to be decanted and re-acidified with nitric acid to reform the precipitate and definitively confirm the presence in the chloride neutron.

Silver nitrate was going to be included in iodide remedy and the creation of a yellow-colored precipitate, metallic iodide, would confirm the existence of iodide anions. One other sample of iodide answer was to always be reacted with drops of acetic acid right up until sufficiently acid. Potassium nitrate was to end up being added to the perfect solution is causing a color change. Methylene chloride was to be in addition to this sample and shaken to confirm the presence of iodide anions simply by forming two separate and differently colored layers. A barium chloride-calcium chloride mixture was to be added to sulphate solution and heated to 90oC. The sample was going to stand for a period of time to allow the organization of awhite precipitate, ba (symbol) sulphate, confirming the presence of the sulphate neutron. The addition of hydrochloric acid and subsequent heating were to have zero effect on the presence, additional confirming arsenic intoxication sulphate anions.




Test pontoons

Carbonate Solution

Test pipe rack

Concentrated Sulphuric acid, H2SO4

Vision dropper

6M Hydrochloric acid, HCL

Graduated pipette

Barium hydroxide solution Ba(OH)2

Pipette bulb

Chloride option, Cl-

Pasteur pipette

Iodide solution, I-


zero. 1M Sterling silver nitrate, AgNO3


Focused Ammonium hydroxide, NH4OH

6M Nitric chemical p, HNO3

6M Acetic acid. HC2H3O2

Potassium nitrate, KNO2

Methylene chloride solution, CH2Cl2

Sulphate solution

Barium chloride-Calcium chloride mixture, BaCl2-CaCl2

Unknown Test 7


Carbonate solution is definitely hazardous in the event of skin get in touch with (sensitizer, irritant), of eye-to-eye contact (irritant), breathing (lung irritant), and consumption. It should be stored in a cool, well-ventilated region. In case of leak, use suitable tools to place the leaking solid within a convenient waste disposal container and neutralize the residue with a dilute solution of lactic acid. Hydrochloric acid is very dangerous in case of skin contact (sensitizer, corrosive, irritant, permeator), fixing their gaze (corrosive, irritant), of inhalation (lung sensitizer, respiratory tract irritant), and ingestion (toxic). It ought to be kept in a dry pot, kept far from oxidizing real estate agents, organic components, metals, alkalis, and dampness. In case of drip, dilute with water and mop with an inert dry material. Residue ought to be neutralized with dilute sodium carbonate. Chloride solution is usually hazardous in case of skin get in touch with (irritant, permeator), of fixing their gaze (irritant), ingestion, and breathing (irritant).

In case there is spill, water down with normal water and cleaner with a great inert dry out material and spread drinking water on the contaminated surface. Iodide solution is lightly harmful in case of skin area contact (irritant), of eye contact (irritant), of ingestion, and inhalation. In case there is spill, make use of appropriate tools to put the spilled solid in a practical waste disposal container. And spread water within the contaminated area. Silver nitrate is very harmful in case of pores and skin contact (corrosive, permeator), of eye contact (irritant), of breathing, and consumption.. Silver nitrate kept away from heat, types of ignition, and combustible material. In case of leak, use appropriate tools that will put the leaking solid in a convenient garbage disposal container. Ammonium hydroxide is extremely hazardous in case there is skin get in touch with (toxic, corrosive, irritant, permeator), eye contact (irritant), inhalation (toxic to higher respiratory tract), and ingestion (toxic). Drinking water should never be put into ammonium hydroxide and it must be kept away from incompatibles such as metals, stomach acids. In case of spill, dilute with water and mop with inert dried out material.

Neutralize residue with dilute acetic acid. Nitric acid is very dangerous incase of skin get in touch with (corrosive, annoyance, permeator), of eye contact (irritant, corrosive), and ingestion. It can be slightly unsafe in case of inhalation (lung sensitizer, respiratory tract and mucus membrane layer irritant). Nitric acid can be explosive in the presence of reducing materials, of organic materials, of metals, of alkalis. In case there is spill, water down with drinking water, mop with an inert dry, and neutralize the residue using a dilute solution of sodium carbonate. Acetic acid is very unsafe in case of skin area contact (irritant), of eye-to-eye contact (irritant), of ingestion, of inhalation. It truly is hazardous in the event of skin speak to (corrosive, permeator), of eye contact (corrosive). It ought to be kept away from sources of temperature, ignition, and oxidizing materials. In case of drip, Dilute with water, mop with an inert dried out, and counteract the residue with a water down solution of sodium carbonate.

Potassium nitrite is extremely dangerous in case of skin area contact (corrosive, irritant), of eye contact (irritant), of ingestion, and inhalation. In case of leak, use appropriate tools to put the leaking solid within a convenient waste disposal container. Potassium nitrite should be kept dried, away from types of ignition, temperature, and flammable materials. Methylene chloride is very hazardous in case of eye contact (irritant), of ingestion, of inhalation, and skin speak to (irritant, permeator). In case of drip dilute with water and mop with an inert dry materials. Sulphate remedy is unsafe in case of eye contact (irritant), skin contact (irritant), and ingestion. In case of epidermis contact, wash with water and soap, and cover area with an emollient. In case of leak, Dilute with water, cleaner with a great inert dried out material pass on water within the contaminated surface area. (ScienceLab, 2005)


Please refer to Lab 3: Qualitative Analysis Part 2- Anions hormone balance Laboratory Manual 2013-2014, Clarington College, pages 11-12 pertaining to full set of Materials and Methods.


Table 1a: Testing to get the presence of Carbonate, CO32- anions

a couple of drops concentrated H2SO4 added, Test conduit shaken

Additional Observations

Carbonate Solution, 3mL

vim seen as colourless gas soars from bottom of check tube evaluation tube

feels very much warmer, upon wafting the gas contains a mildly distressing, acrid smell The presence of an effervescent response indicated that the sample got carbonate anions present.

Desk 1b: Screening for occurrence of Carbon, CO2 to verify the presence of CO32- anions

two drops 6M HCl

1 drop BaOH hanging over test out tube

Carbonate Remedy, 3mL

small amount of spirit noted

about your five seconds after being hanging over test tube, the base of the scrap clouded with white precipitate The addition of HCl to the test resulted in several rising gas bubbles, indicated that a gas was being produced. The clouding of the ba (symbol) hydroxide droplet indicated it had been reacting with carbon dioxide getting away the tube and thus confirmed the presence of carbonate anions in the sample. Stand 2: Tests and credit reporting for the existence of Chloride, Cl- anions

5 drops 0. 1M AgNO3 added

NH4OH is definitely added drop-wise

Supernatant solution is decanted

6M HNO3 is added

Chloride Solution, 5mL

gloomy white medications formed

precipitate partly dissolved upon addition, specific clear supernatant formed above remaining medications cloudy white colored precipitate converted, small white granulations settled at underlying part of check tube six drops of ammonium hydroxide, NH4OH, were added to the sample 6th drops of the nitric, HNO3, were put into acidify the sample The formation of a cloudy white medications in the existence of sterling silver nitrate mentioned that the test had chloride anions present. The subsequent addition of ammonium and re-acidification of the sample resulted in the reformation of any cloudy whit precipitate, thus confirming arsenic intoxication chloride anions. Table 3a: Testing for the presence of Iodide, I- anions

5 drops 0. 1M AgNo3 added

Iodide Solution, 5mL

cloudy pale discolored precipitate created

Arsenic intoxication a over cast yellow precipitate with sterling silver nitrate indicates presence of iodide ion. Table 3b: Testing and confirming arsenic intoxication Iodide, I- anions

Acetic acid is added drop-wise

2 drops KNO2 added

12-15 drops Methylene chloride added, test tube shaken

Iodide Option, 5mL

Blue Litmus Paper proved the solution was acidic simply by turning reddish solution switched a mustard-brown colour

2 specific layers formed in the check tube. The base layer was reddish green, and the top layer was a burnt-orange color 2 drops of lactic acid, HC2H3O2, had been added to hydrogenate sample After confirming the sample was indeed acid, it reacted with the potassium nitrate to alter to a mustard-brown colour. Digging in the methylene chloride shaped 2 distinctly coloured levels, thus credit reporting that the remedy had iodide anions present.

Table some: Testing and confirming the existence of Sulphate SO42- anions

0. 5mL of BaCl2-CaCl2 blend added

Test tube heated, was standing for 5 minutes

your five drops 6M HCl, test out tube heated

Sulphate Solution, 3mL

very faint wisps of over cast white medicine appeared

noticeable over cast white medicine distributed throughout solution addition of HCl made evaluation tube comfortable feeling

after heating test out tube precipitate remained distributed in answer In every instance of heating, test tube was placed in a boiling water bath at 90oC The final heating of the evaluation tube was for approximately 5minutes at 90oC The reaction in the sulphate solution with the ba (symbol) chloride-calciumchloride solution, when warmed, resulted in the appearance of a fine white precipitate, indicating the test had sulphate anions present. The subsequent addition of HCl and reheating resulting in the solution remaining comparatively the same further more confirmed that sulphate anions were present. Table 5a: Testing to get Unknown Test 7 intended for the presence of Carbonate, CO32- anions

2 drops concentrated H2SO4 added, Evaluation tube shaken

Added Observations

Unknown Sample 7, 3mL

zero visible spirit

not any noticeable in order to test tube’s temperature

The lack of effervescence and warmth produced by the sample mentioned the absence of carbonate anions in the sample. Table 5b: Testing Unidentified Sample pertaining to presence of Carbon Dioxide, CO2 to confirm the presence of CO32- anions

2 drops 6M HCl

you drop BaOH suspended over test conduit

Unidentified Sample 7, 3mL

no visible effervescence

suspended scrap remained clear, despite being held above test pipe for a minute The sample did not react with the hydrochloric acid to make a gas that reacted with the barium hydroxide, thus the suspended scrap remained crystal clear. The benefits further affirmed the lack of carbonate anions. Table six: Testing and confirming Not known Sample intended for the presence of Chloride, Cl- anions

5 drops 0. 1M AgNO3 added

NH4OH is added drop-wise

Supernatant remedy is decanted

6M HNO3 is definitely added

Unknown Test 7, 5mL

soft yellow medicine formed

no in order to solution

no change to solution

6 drops of ammonium hydroxide, NH4OH, were put into the test Nitric acid, HNO3, was unable to be added to the precipitate since no very clear supernatant was formed The lack of creation of a over cast white medicine in the existence of silver precious metal nitrate suggested that the sample did not possess chloride anions present. The following addition of ammonium and re-acidification with the sample had been rendered purposeless. Table 7a: Testing Unknown Sample to get the presence of Iodide, I- anions

5 drops 0. 1M AgNo3 added

Unidentified Sample several, 5mL

cloudy soft yellow medicine formed

The presence of a cloudy discolored precipitate with silver nitrate indicates presence of iodide anion. Table 7b: Tests and credit reporting Unknown Test for arsenic intoxication Iodide, I- anions

Acetic acid is added drop-wise

2 drops KNO2 added

12-15 drops Methylene chloride added, test tube shaken

Unknown Test, 5mL

Blue Litmus Paper proved the solution was acidic by turning red solution turned a mustard-orange colour2 distinct layers created in the test tube. The bottom layer was reddish-purple, plus the top level was an orange-brown two drops of acetic acid, HC2H3O2, were added to acidify sample Upon confirming the test was indeed acidic, this reacted while using potassium nitrate to change to a mustard-orange shade. The addition of the methylene chloride formed two distinctly colored layers, hence confirming that the solution experienced iodide anions present. Desk 8: Tests and confirming Unknown Sample for the existence of Sulphate SO42- anions

zero. 5mL of BaCl2-CaCl2 combination added

Test pipe heated, stood for 5 minutes

five drops 6M HCl, evaluation tube heated

Unfamiliar Sample, 3mL

zero precipitate shaped

zero noticeable medications formed

no in order to solution

In each instance of heating, quality tube was placed in a boiling water bathroom at 90oC The final heat of the check tube was for approximately 5minutes at 90oC The lack of medications formation in the test indicated that the test was missing of sulphate anions. This result was further verified by the succeeding addition of hydrochloric chemical p and reheating failing to produce a precipitate.


A powerful acid such as H2SO4, sulphuric acid, along with carbonate generates an energetic reaction as a result of formation of carbon dioxide. The heat felt from the test conduit was a consequence of the exothermic reaction the fact that carbonate answer underwent inside the presence of your strong chemical p. Sulfuric chemical p is a solid acid, nevertheless only for the first They would, so it dissociates into H+ ion as well as the bisulfate ion, HSO4-. HSO4- is a weak acid and dissociate to a great extent, but it also reacts with carbonate (Dartmouth College, 2003). The existence of sulphur may well have made up the slightly unpleasant aroma wafted throughout the experiment. As indicated by results of Table 1b, the formation of CO2 served as a positive indicator for the presence of CO32- in a solution, as indicated by: 2H+(aq) + CO32-(aq) ‘ H2O(l) + CO2(g).

The exposure of the made gas, co2, to barium hydroxide ended in the a cloudy light precipitate as a result of formation of barium carbonate as indicated by: WATER (l) & CO2 (aq) + Ba2+(aq) ‘ BaCO2 (s) + 2 H+(aq). The addition of 01M AgNO3, silver precious metal nitrate, for the chloride option resulted in the organization of a white-colored precipitate because of the formation of silver chloride as indicated by: AgNO3 (aq) & Cl-(aq) ‘ AgCl(s) & NO3 (g). It is interesting to note that chlorides are generally soluble, except for lead(II) and silver chloride. When concentrated NH4OH was added to the silver chloride precipitate mixed due to the creation of an ammine complex, [Ag(NH3)2]&. Silver nitrate is generally acidified with water down nitric acid solution to prevent the precipitation of other non-halide silver salts (Brown, 2012).

Nitric acid acidified the perfect solution due to the addition of H+ ions to the solution, leading to re-precipitation, thus definitively implying the presence of chloride anions. This is expressed because AgCl(s) +2NH3(aq) ‘ Ag(NH3)2+(aq) + Cl-(aq) Ag(NH3)2+(aq) + Cl-(aq) & 2H+(aq) ‘ AgCl(s) + 2NH4+(aq) The addition of 0. 1M AgNO3 to the iodide option resulted in the formation of a gloomy yellow medications as stated by: AgNO3(aq) + I- ‘ AgI(s), which like a precipitate can be insoluble in concentrated freezing mixture. The addition of 6M acetic acid, HC2H3O2, acidified the perfect solution is, as confirmed by the litmus test. The newly acidic solution reacted with potassium nitrite, KNO2, reducing the nitrite to nitrogen dioxide as expressed by: I-(aq) + KNO2 ‘ KI(aq) + NO2(g). The liberation of iodine in the response resulted in a brownish change in colouration in the solution (SUNY Chemisty, 2005). The failing of the sample to turn a reddish-brown might have been a method to obtain error because of a failure to sufficiently rinse your cleaned evaluation tube with DI drinking water.

Methylene chloride, CH2Cl2, which is a nonpolar organic compound was added to the perfect solution is reacted with the iodide in the solution to kind a purple coloured coating of denser solution, which usually settled at the bottom of the evaluation tube. An alternative means of testing for arsenic intoxication iodide anions would have been to use starch, which manera a attribute blue-black intricate. The addition of the barium chloride-calcium chloride mixture, BaCl2-CaCl2, to the sulfate option resulted in the formation of an absurde white sulphate, barium sulphate as indicated by: Ba2+(aq) + SO42-(aq) ‘ BaSO4(s). Other insoluble barium debris contain anions of fragile acids (CO32-, SO32-and PO43-). Precipitation of such anions is usually prevented by simply acidifying the perfect solution (Yoder, 2014). The products in the reaction were created more dominant by the catalyzing the reaction with heat, creating a more noticeably fine white colored precipitate distributed throughout the solution.

The addition of 6M HCl, hydrochloric acid, served to isomerize the solution, further illustrating the insolubility with the barium sulfate precipitate, thereby confirming the existence of sulphate anions. The not known sample was placed through all confirmatory tests. It failed to react with Sulphuric acid and hydrochloric acid solution to produce an effervescent effect, indicating it was carbonate lack of. Unknown Test 7 would not react with all the BaCl2-CaCl2 mixture to form a medications regardless of warmth, indicating the absence of sulphate anions. Unfamiliar Sample 7 formed a pale cloudy yellow medications upon digging in silver nitrate, immediately implying the presence of iodide anions, disqualifying the need to testfurther for chloride. The addition of acetic acid to Not known Sample 7 provide a enough acidic environment for the potassium nitrate to release iodine, thus the answer appeared being a dark mustard orange. The methylene chloride confirmed the presence of iodide ion when a unique reddish-purple coating settled at the end of one other distinctly colored layer of solution.


Based on the results in the experiment, Unfamiliar Sample 7 demonstrated the organization of a medicine in the existence silver nitrate, a change in colouration once mixed with potassium nitrate, as well as the formation of 2 distinctly coloured layers when ever methylene chloride was included in the solution and shaken. In accordance with the substance properties showed by the 5 known anions during the qualitative testing, it can be concluded the Unknown Test 4 obviously demonstrated the characteristic chemical substance responses of any solution with I- ions present.


1 ) An ion is an atom which includes lost or perhaps gained an electron to create a charged compound.

installment payments on your An corpuscule is a negatively charged particle due to the atom gaining one or more electrons. A cation can be described as positively incurred particle due to the atom shedding one or more bad particals.

3. H2SO4(aq) & Na2CO3(aq) ‘ Na2SO4(aq) & H2O(l) & CO2(g)

4a. Aluminum ion: Group IIIA, Al3+

4b. Sulphur ion: Group VIA, S2-

4c. Iodide ion: Group VIIA, I-

4d. Fresh air ion: Group VIA, O2-

4e. Chloride ion: Group VIIA, Cl-


Birk, M. P. (2001, December 4). General Hormone balance With Qualitative Analysis. Recovered from Arizona State University: http://www.public.asu.edu/~jpbirk/qual/qual.html Brownish, W. (2012). Chemical Tests. Retrieved from Doc Brown’s Chemistry: http://www.docbrown.info/page13/ChemicalTests/ChemicalTestsa.htm Dartmouth

College. (2003, May). ChemLab Chapter five. Retrieved by Qualitative Research of Cations: http://www.dartmouth.edu/~chemlab/chem3-5/qual_an/overview/procedure.html ScienceLab. (2005, October 10). Materials Safety Data Sheet (MSDS) List. Retrieved from Scientific research Lab: http://www.sciencelab.com/msdsList.php SUNY Chemisty. (2005, December). Anion Research. Retrieved by Chemistry 112: http://employees.oneonta.edu/kotzjc/LAB/Anion.pdf Tro, N. L. (2011). Necessary Introductory Biochemistry (4th ed. ). Toronto: Prentice Area. White, 3rd there’s r. (2013-2014). Qualitative Analysis Component 2- Anions. Chemistry 1 Laboratory Manual, 7-9. Yoder, C. (2014, November). Qualitative Analysis of CAans and Anions. Recovered from Born Chemist: http://www.wiredchemist.com/chemistry/instructional/laboratory-tutorials/qualitative-analysis

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