17. Two complexes Cr(H.0).CI, (A) and C NH) , (B) are violet and yellow coloured respectively. The incorrect statement regarding them is (a) 4 value for (A) is less than that of (B) (b) A values of (A) and (3) are calculated from the energies of violet and yellow light respectively ( both absorb energies corresponding to their complementary colours (d) both are paramagnetic with three unpaired electrons

Two complexes [Cr(H_(2)O_(6))_(6)]Cl_(3) and [Cr(NH_(3))_(6)]Cl_(3) (B) are violet and yellow coloured, respectively. The incorrect statement regarding them is :

Two complexes [Cr(H_(2)O_(6))_(6)]Cl_(3) and [Cr(NH_(3))_(6)]Cl_(3) (B) are violet and yellow coloured, respectively. The incorrect statement regarding them is :

Two complexes [Cr(H_(2)O_(6))_(6)]Cl_(3) and [Cr(NH_(3))_(6)]Cl_(3) (B) are violet and yellow coloured, respectively. The incorrect statement regarding them is :

The transition metals and their compounds have paramagnetic properties. This is due to the reason that ions of transition metals have unpaired electrons in (n-1)d orbitals. As the number of unpaired Sc to Mn, the paramagnetic character increases accodingly. From Mn onwards, this character decreases as electrons get paired up. The paramagnetic behaviour is expressed in terms of magnetic moment which is because of the spin of unpaired electron (n). It is given as Magnetic moment = sqrt(n(n+2))B.M Majority of transition metal compounds are coloured both in solid state as well as in aqueous solution. due to d-d transition in which unpaired electrons from the lower energy d-orbitals are transferred to higher energy d-orbitals. The energy of this transition correspond to the radiation in visibe region. Thus, when white light falls on such a transition metal compound, some light energy corresponding to a particular colour is absorbed and one or more electrons are raised from lower energy set of orbitals to those of higher energy. With the absorption of radiations corresponding to specific colour from the white light, a colour known asd the complementary colour is observed or transmitted. The compound which have the same magnetic moment like that of FeCl_(2)

Assertion (A) : Non-stoichiometric compounds are called Bertholide compounds. NaCl and KCl crystal, when heated in an atmosphere of Na and K varpours, respectively, they impart violet and yellow colours to NaCl and KCl , respectively. Reason (R ) : Metal excess defect is due to the presence of extra cations atg the interstitial sites. The excess metal ions move to the interstitial sites and the electrons to the neighbouring sites. The colour results byt the excitation of these electrons by absorbing suitable energy from visible light. When the excited electroon comes back to the ground state, there is emission of radiation in the visible region and gives complimentary colour.