Problem 15
Which of the following are coloured due to charge transfer spectra (a) \(\mathrm{CrO}_{3}\) (b) \(\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right) \mathrm{NO}\right] \mathrm{SO}_{4}\) (c) \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (d) All of these
Problem 17
For which lanthanide are \(+2\) and \(+3\) oxidation states are common? (a) Eu (b) \(\mathrm{Na}\) (c) \(\mathrm{Ce}\) (d) \(\mathrm{La}\)
Problem 18
An alkaline solution of ___ and citrate ions is called ___. (a) silver chloride; Tollen's reagent (b) cupric sulphate; Benedict's solution (c) silver nitrate; Fehling's solution (d) cupric sulphate; Schiff's reagents
Problem 19
Ferrous ion changes to \(\mathrm{X}\) ion, on reacting with acidified hydrogen peroxide. The number of d-electrons present in \(\mathrm{X}\) and its magnetic moment (in B.M.) are respectively (a) 5 and \(4.9\) (b) 4 and \(5.92\) (c) 6 and \(6.95\) (d) 5 and \(5.92\)
Problem 20
Which one of the following characteristics of the transition metal is associated with their catalytic activity? (a) variable oxidation states (b) colour of hydrated ions (c) paramagnetic behaviour (d) high enthalpy of atomization
Problem 21
Iron loses its magnetic property at (a) melting point (b) curie point (c) \(1000 \mathrm{~K}\) (d) boiling point
Problem 22
In the extraction of zinc, the formation of blue flame is due to the burning of (a) \(\mathrm{C}\) (b) \(\mathrm{CO}\) (c) \(\mathrm{Zn}\) (d) \(\mathrm{ZnO}\)
Problem 23
Which one of the following ions exhibits colour in aqueous solution? (a) \(\mathrm{Ti}^{4+}\) (b) \(\mathrm{Zn}^{2+}\) (c) \(\mathrm{Ni}^{2+}\) (d) \(\mathrm{Sc}^{3+}\)
Problem 25
Which one of the following ions is colourless in its aqueous solution? (a) \(\mathrm{Ti}^{3+}\) (b) \(\mathrm{Cu}^{2+}\) (c) \(\mathrm{Ni}^{2+}\) (d) \(\mathrm{Zn}^{2+}\)
Problem 26
Which one of the following ions exhibit highest magnetic moment? (a) \(\mathrm{Cu}^{2+}\) (b) \(\mathrm{Ti}^{3+}\) (c) \(\mathrm{Ni}^{2+}\) (d) \(\mathrm{Mn}^{2+}\)
