17_18_46_9_08_2024_Qualitative Analysis-1

Chemistry Notes

Page 1

• Qualitative Analysis

  • Involves detecting cations and anions in salts or mixtures.

• Physical Examination of the Mixture

  • Observations and Inferences

    • Color

      • Blue or bluish green: Cu2+ or Ni2+

      • Greenish: Ni2+

      • Light green: Fe2+

      • Dark brown: Fe3+

      • Pink violet: Co2+

      • Light pink, flesh color, or dull earthy color: Mn2+

    • Smell

      • Ammonical smell: NH4+

      • Vinegar-like smell: CH3COO–

      • Rotten eggs smell: S2–

    • Density

      • Heavy: Salt of Pb2+ or Ba2+

      • Light fluffy powder: CO3 2–

    • Deliquescence

      • Salt absorbs moisture and becomes paste-like.

Page 2

• Dry Heating Test

  • Observations and Inferences

    • Gas Evolved

    • Sublimate Formed

    • Decrepitation

    • Fusion

    • Swelling

    • Residue

Page 3

• Detection of Gas Evolved

  • Charcoal Cavity Test

• Cobalt Nitrate Test

Page 4

• Flame Test

  • Color of Flame

• Borax Bead Test

Page 5

• Color in oxidizing and reducing flames

• Solubility Chart

Page 6

• Analysis of Anions (Acidic Radicals)

  • Group 'A' Radicals with observations and inferences

Page 7

• Concentrated Sulphuric Acid Group

  • Group 'B' Radicals with precipitation reactions and oxidation/reduction in solutions

Page 8

• Preparation of Sodium Carbonate Extract

  • Individual tests for Group 'A' Radicals like carbonate ion and sulphite ion

Page 9

• Continued tests for sulphide ion

Page 10

• Tests for nitrite ion and acetate ion

Page 11

• Test common to halides Cl–, Br–, I–

• Action of heat on halides, specifically chloride ion

These notes cover various qualitative analysis tests for detecting cations and anions in salts or mixtures, including observations, inferences, and specific tests for different ions.

Chemistry Notes

Page 12

• Qualitative Analysis of Bromide Ion (Br¯)

  • Reactions involving Bromide Ion:

    • Formation of precipitate

    • Formation of gas

    • Other reactions with specific reagents

Page 13

• Chemistry of Iodide Ion (I¯) and Nitrate Ion (NO3¯)

  • Iodide Ion reactions:

    • Formation of precipitate

    • Other specific reactions

  • Nitrate Ion reactions:

    • Formation of precipitate

    • Additional reactions with reagents

Page 14

• Qualitative Analysis Continued

  • Action of Heat:

    • Reactions under gentle warming

    • Group of anions not reacting with H2SO4 but giving precipitates with certain reagents

  • Sulphate Ion (SO4 2–) reactions:

    • Reactions with dilute and concentrated H2SO4

    • Precipitation reactions with specific reagents

Page 15

• Chemistry of Phosphate Ion (PO4 3–) and Borate Ion (BO3 3–)

  • Phosphate Ion reactions:

    • Formation of precipitate

  • Borate Ion reactions:

    • Specific reactions mentioned

Page 18

• Qualitative Analysis Lecture II: Analysis of Cations (Basic Radicals)

  • Note:

    • Details about groups, reagents, and precipitate colors for cation analysis.

Chemistry Notes

Page 19

• Analysis of Cations

  • Group 1st radical (Ag+, Pb2+, Hg22+) precipitated as chloride due to low solubility product.

  • Hydroxides do not precipitate in acidic medium.

  • Group 2nd radical precipitated as sulphide due to low solubility.

  • Group 4th cations precipitated with ammonium hydroxide.

  • Use of HCl to decrease S2- concentration.

  • Avoid using H2SO4 instead of HCl.

• Original Solution Preparation

  • Used for basic radical analysis except NH4+.

  • Prepared by dissolving salt in suitable solvent.

  • NH4Cl suppresses ionization for group 3 cations precipitation.

  • Differentiation between soluble and insoluble salts/mixtures.

  • Sequential dissolution in H2O, dil. HCl, and conc. HCl based on solubility.

  • Boiling off H2S in 2nd to 3rd group transition.

  • Oxidation of Fe2+ to Fe+3 in the original solution.

Page 20

• Qualitative Analysis

  • Detection of Ammonium Ion (NH4+) using Sodium Hydroxide Solution.

  • Tests involving Nessler's Reagent, Sodium Hexanitritocobaltate (III) Solution, etc.

  • Initial focus on 1st group cations (Pb2+, Hg22+, Ag+).

Page 21

• Lead Ion (Pb+2)

  • Precipitation reactions for lead ion.

Page 22

• Mercury Ion (Hg2 2+) and Silver Ion (Ag+)

  • Precipitation reactions for mercury and silver ions.

Chemistry Notes

Page 23

• IInd Group: Hg2+, Pb2+, Bi3+, Cu2+, Cd2+, As3+, Sb3+, Sn2+

  • IIA Group: Hg2+, Pb2+, Bi3+, Cu2+, Cd2+

Page 24

• Mercury Ion (Hg2+)

  • Series of reactions involving H+ ions and precipitation

• Copper Ion (Cu+2)

  • Involves heat in the reaction

Page 25

• Bismuth Ion (Bi+3)

  • Reactions leading to precipitation

• Cadmium Ion (Cd+2)

  • Series of reactions

Page 26

• Lead Ion (Pb2+)

  • Precipitation reactions

• IIB Group: As3+, Sb3+, Sn2+, Sn4+

Page 27

• Arsenic Ion (As+3)

  • Involves heat in the reaction

• Antimony Ion (Sb+3)

  • Series of reactions

• Tin (II) Ion (Sn+2) and Tin (IV) Ion (Sn+4)

  • Precipitation reactions

Page 28

• Sn

  • Reactions leading to precipitation

• IIIrd Group: Al+3, Cr+3, Fe+3

Page 29

• Aluminimum Ion (Al3+)

  • Reactions with NH4Cl leading to precipitation

• Iron Ion (Fe3+)

  • Involves heat in the reaction

Page 30

• Series of reactions involving different ions

• Important Note: Specific reactions mentioned

Page 31

• Chromium Ion (Cr3+)

  • Series of reactions involving CH3OOH and amyl alcohol

Chemistry Notes

Page 32

• Qualitative Analysis of IVth Group (Zn+2, Mn+2, Ni+2, Co+2)

  • Manganese Ion (Mn2+):

    • Precipitation reactions indicated by arrows.

    • Specific reactions leading to precipitation or not.

Page 33

• Zinc Ion (Zn2+)

  • Behavior in neutral solutions.

    • Partial precipitation with specific reactions.

    • Formation of complexes indicated by arrows.

Page 34

• Qualitative Analysis of Cobalt Ion (Co2+)

  • Reactions involving NH4OH.

    • Precipitation or non-precipitation indicated.

    • Formation of complexes and specific reactions shown.

Page 35

• Nickel Ion (Ni2+)

  • Reactions with NH4OH.

    • Formation of complexes and precipitation.

    • Specific reactions leading to different outcomes.

Page 36

• Qualitative Analysis of Vth Group (Ba2+, Sr2+, Ca2+)

  • Barium Ion (Ba2+):

    • Specific reactions leading to precipitation or not.

  • Strontium Ion (Sr2+):

    • Reactions and outcomes shown.

• Calcium Ion (Ca2+)

  • Example reactions and outcomes.

• Magnesium Ion (Mg2+)