Multiple Choice QuestionsThe aqueous ferrous ion is green, ferric ion is pale yellow. The aqueous chromic ion is green, hence the colour of chromate ion must be
orange
colourless
yellow
red
C.
yellow
Most of the compounds of transition metals are coloured in solid as well as solution state. Colour in transition metal ions is usually due to electron transition within the d-shell. Intensely coloured ions with the metal in its highest oxidaton state (e.g., Mn7+, Cr6+, Fe6+) derive the colour from electrons transitions between the metal and the oxygen atom.
Iron:
(i) Fe2+ is green.
(ii) Fe3+ is pale yellow in colour.
Chromium : The colour of chromic ion, i.e., Cr3+ depends around the ligand around the ion. Aqueous solution contains the violet octahedral hexaaquachromium (III) ion, but when some of the water ligands are replaced by other species, such Cr3+ ions are green.
In chromate ion (CrO), Cr occurs in +6 oxidation state and it is yellow in colour.
CO2 acts as electrophile in which reaction?
Williamson's reaction
Kolbe reaction
Perkin's reaction
Reimer-Tiemann reaction
Which one of the following undergoes aldol condensation?
Acetaldehyde
Propanaldehyde
Acetone
All of these
Except one, the other three are isomers, find odd man out
| ethanol | oxiran | oxitane | vinyl alcohol |
| (1) | (2) | (3) | (4) |
vinyl alcohol
ethanol
oxiran
oxitane
One amine is more basic than ammonia and the other is less basic than ammonia. The two amines are respectively
N-methyl ethanamine and N, N-dimethyl ethanamine
aniline and N-methyl aniline
N-methyl aniline and aniline
N, N-dimethyl aniline and benzenamine
One of the isomer of C4H11N is optically active. It must be a
primary amine
secondary amine
tertiary amine
all isomers are optically inactive
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