3B Analatical Chemistry Flashcards
2 types of study in analatical chemistry
Qualitative and Quantitative
Qualitative analysis includes
Identification of an unknown substance by chemical tests.
Chemical tests include the use of
- Sodium and Ammonium Hydroxides on salt solution.
2. Observation of color and solubility of the precipitates formed.
A salt is colored if
Its cation or anion is colored.
Salts of elements in group ______ are colorless
1,2 and 13 to 17 are colorless.
Salts of elements in group ______ are colored
3 to 12
Name the color of the following elements:
- Cu2+
- Cr3+
- Mn2+
- Fe2+
- Fe3+
- Co2+
- Ni2+
- Blue
- Green
- Pink
- Green
- Brown or yellow
- Blue or pink
- Green
Cr2O7
MnO4
Orange
Pink/Purple
Calcium with NaOH
White insoluble
Magnesium with NaOH
Dull white insoluble
Iron (II) with NaOH
Dirty green Insoluble
Iron (III) with NaOH
Reddish brown insoluble
Cu2+ with NaOH
Pale blue Insoluble
Zn with NaOH
Gelatinous white soluble
Zn(OH)2 Can further react with ______ to form ______.
NaOH, Na2ZnO2
Pb(NO3)2 Can further react with _______ to form _______.
NaOH, Na2PbO2.
Both sodium zincate and Sodium plumbite gives a
Colorless soltion
Ca with NH4(OH)
Cant form a precipitate
Why does Ca not react with NH4(OH)
Concentration of OH- ions is low.
Mg with NH4(OH)
Dull white Insoluble
Fe2+ with NH4(OH)
Dirty green insoluble
Fe3+ with NH4(OH)
Reddish brown Insoluble
Cu2+ with NH4(OH)
Pale blue soluble
Cu(OH)2 can further react with ______- to give _____ and ______.
It can react with ______ and ______- to give ________ and ________.
(NH4OH)
NH4OH, [Cu(NH3)4] (OH) 2 -> Tetramine copper hydroxide.
NH4OH, (NH4)2SO4, [Cu(NH3)4] (SO4) -> Tetra amine copper sulphate.
Tetra amine copper (sulphate and hydroxide) gives a
Inky blue for suplhate only and Deep blue solution for both.
Zn with NH4(OH)
White gelatinous soluble/dirty white
Zn(OH)2 can further react with ______- to give _____ and ______.
It can react with ______ and ______- to give ________ and ________.
(NH4OH)
NH4OH, [Zn(NH3)4] (OH) 2 -> Tetramine Zinc hydroxide.
NH4OH, (NH4)2SO4, [Zn(NH3)4] (SO4) -> Tetra amine Zinc sulphate.
Tetra amine Zinc (sulphate and hydroxide) gives a
Colorless
In both the “further” reactions of Zn and Cu, what should be in excess?
NH4(OH)
Lead with NH4(OH)
Chalky white insoluble
Zn + NaOH
Na2ZnO2 + H2
Which metal requires water to from “-ate”
Aluminium only.
Metals + hot conc. caustic alkalis ->
Soluble salt + Hydrogen
____ and ____ of _____, ___ and _______ are amphoteric.
Hydroxides; Oxides; Zn, Al and Pb
Amphoteric oxides reacts with ___ alkalis
Hot and Concentrated
This -ate, doesnt have any prefeix always.
Aluminium only; Others have “2” as the subscript
