Identify the alkyne in the following sequence of reactions,
Alkyne A B CH2=CH2
H3C-C≡C-CH3
H3C-CH2-C≡CH
H2C=CH-C≡CH
HC≡C-CH2-C≡CH
Which of the following is a correct statement?
Aqueous solutions of Cu+ and Zn2+ are colourless
Aqueous solutions of Cu2+ and Zn2+ are colourless
Aqueous solution of Fe3+ is green in colour
Aqueous solution of MnO-4 is colourless
A.
Aqueous solutions of Cu+ and Zn2+ are colourless
(a) Cu+ = [Ar] 3d10
(No unpaired electrons, so It is colourless)
Zn2+= [Ar] 3d10
(No unpaired electrons, so it is colourless).
(b) Cu2+ = [Ar] 3d9
(One unpaired electron is present, so it is coloured). Zn2+ is colourless.
(c) The colour of Fe2+ is green while that of Fe3+ is blue.
(d) MnO-4, contains no unpaired electrons, however, it is coloured due to charge transfer.
Thus, only statement given in option (a) is correct.
The percentage of lanthanides and iron respectively in misch metal are
50, 50
75, 25
90, 10
95, 5
Which one of the following ions has same number of unpaired electrons as those present in V+ ion?
Fe3+
Ni2+
Mn2+
Cr3+
Which of the following characteristics of the transition metals is associated with their catalytic activity?
Colour of hydrated ions
Diamagnetic behaviour
Paramagnetic behaviour
Variable oxidation states
Which of the ions having following electronic structure would have maximum magnetic moment?
1s2, 2s2, 2p6,3s2,3p6,3d3
1s2, 2s2, 2p6,3s2,3p6,3d5
1s2, 2s2, 2p6,3s2,3p6,3d7
1s2, 2s2, 2p6,3s2,3p6,3d9