General
✓✗The study of the chemistry of actinoids is difficult because
- they do not form compounds
- they are very common
- they are radioactive and many have short half-lives, and many are made only in small amounts
- they are gases
General
✓✗Which of the following lanthanoids shows the +2 oxidation state?
- La and Lu
- Gd and Lu
- Eu and Yb
- Ce and Tb
General
✓✗The only oxidation state shown by scandium in its compounds is
- +3
- +2
- +1
- +4
General
✓✗The incorrect statement among the following is
- most of the trivalent lanthanoid ions are colourless in the solid state
- actinoids are highly reactive metals, especially when finely divided
- lanthanoids are good conductors of heat and electricity
- actinoid contraction is greater from element to element than lanthanoid contraction
General
✓✗Commercially, potassium permanganate is prepared from manganate by
- electrolytic oxidation in alkaline solution
- heating with HCl
- treatment with ammonia
- reduction with carbon
General
✓✗As a result of lanthanoid contraction, the basicity of the lanthanoid hydroxides
- first increases then decreases
- decreases from La(OH)3 to Lu(OH)3
- increases from La(OH)3 to Lu(OH)3
- remains constant
General
✓✗Which of the following configurations is correct for iron?
- 1s2 2s2 2p6 3s2 3p6 4s2 3d5
- 1s2 2s2 2p6 3s2 3p6 4s2 3d7
- 1s2 2s2 2p6 3s2 3p6 4s2 3d6
- 1s2 2s2 2p6 3s2 3p6 3d5
General
✓✗Which of the following metals has the most negative Eo(M2+/M) value among Ti, V, Cr, Mn?
- V
- Ti
- Cr
- Mn
General
✓✗The Eo(M2+/M) value of Mn is more negative than expected from the general trend because
- Mn2+ has a d10 configuration
- Mn has a very high enthalpy of atomisation
- Mn2+ has the stable half-filled d5 configuration
- Mn is a noble metal
General
✓✗Which of the following elements is an actinoid?
- Cerium
- Gadolinium
- Lutetium
- Uranium
General
✓✗KMnO4 reacts with oxalic acid according to the equation
2MnO4− + 5C2O42− + 16H+ → 2Mn2+ + 10CO2 + 8H2O
Here, 20 mL of 0.1 M KMnO4 is equivalent to
2MnO4− + 5C2O42− + 16H+ → 2Mn2+ + 10CO2 + 8H2O
Here, 20 mL of 0.1 M KMnO4 is equivalent to
- 50 mL of 0.5 M H2C2O4
- 20 mL of 0.1 M H2C2O4
- 20 mL of 0.5 M H2C2O4
- 50 mL of 0.1 M H2C2O4
General
✓✗The Eo(M2+/M) value of Zn is more negative than expected because
- Zn2+ has the stable d10 configuration
- Zn has a very high melting point
- Zn has a d5 configuration
- Zn is a transition element
General
✓✗The irregular variation of ionisation enthalpies across the 3d series is mainly due to
- the absence of 4s electrons
- constant atomic radius
- the varying stability of different d configurations (such as d0, d5, d10)
- equal nuclear charge
General
✓✗The enthalpy of atomisation in the first transition series is maximum at about
- Sc
- Cu
- Zn
- the middle of the series (V/Cr)
General
✓✗Mercury (Hg), cadmium (Cd) and zinc (Zn) belong to group
- 14
- 10
- 12
- 2