Class 12 Chemistry Chapter 8 the d and f Block Elements MCQs | Class 12 Chemistry Chapter 8 the d and f Block Elements Objective Type Questions and Answers

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Questions
1 Which of general symbol is used to represent Lanthanoides ?
A Ln
B La
C Le
D Li

Answer:Ln
2 Which of following elements are include in actinide ?
A Th to Lr
B Ac to Lr
C Ac to No
D Th to No

Answer:Th to Lr
3 Which of following radioactive elements in Lanthanodies.
A Promethium (Pm)
B Lutetium (Lu)
C Yetterbium (Yb)
D Samarium (Sm)

Answer: Promethium (Pm)
4 Which of following is used in gas lighters ?
A CeO2
B Pyrophoric Misch metal
C Gadolinium sulphate
D Ceric compounds

Answer:Pyrophoric Misch metal
5 Which of following is used as oxidizing agent in volumetric analysis ?
A Ceric compounds
B CeO2
C Oxides of lanthanoids
D Gadolinium sulphate

Answer: Ceric compounds
6 Which of following is used in preparation of optical glass of camera having high refractive index ?
A ceric compounds
B CeO2
C Oxides of lanthanoids
D Gadolinium sulphate

Answer:Oxides of lanthanoids
7 Which of following is used to produce very low temperature by magnetic field ?
A Pyrophoric misch metal
B Uranium
C Thorium
D Gadolinium sulphate

Answer:Gadolinium sulphate
8 What is the constitution of metals in pyrophoric misch metal ?
A ce-50%, ca-40%, Fe-10%
B Ce-50%, La-40%, Fe-7%, other-5%
C Ce-40%, La-50%, Fe-5%, other-5%
D Ce-40%, La-50%, Fe-10%

Answer:Ce-50%, La-40%, Fe-7%, other-5%
9 Which of following statement is wrong ?
A Atoms of all transition elements are paramagnetic
B All transition elements are metals
C All elements of d-block are transition elements
D D-block elements are present in between s & p block elements in periodic table

Answer: Atoms of all transition elements are paramagnetic
10 Why do theoritical value of magnetic moment differ from their practical value ?
A Due to decrease in volume of metal ion
B Due to unsymmetrical arrangement of dipoles in orbital
C Due to rotation-orbital combination
D Both are different methods to calculate magnetic moment

Answer: Due to rotation-orbital combination
11 What is the value of magnetic moment of central metal ion in K2MnO4 ?
A 0.0 BM
B 1.73 BM
C 2.83 BB
D 3.87 BM

Answer: 1.73 BM
12 What will be obtained when managanese dioxide is fused with KOH in presence of oxidizing agent like KNO3 ? What will be the colour of product ? 
A K2 MnO4 Dark green
B KMnO4, Violet
C Mn2O3, Grey
D Mn2O4, Black

Answer: K2 MnO4 Dark green
13 Which of following group of transition metal is used to prepare currency coins ?
A Cu, Ag, Au
B Ru, Rh, Pd
C Fe, Co, Ni
D Os, Ir, Pt

Answer: Cu, Ag, Au
14 Ce is an important member of Lanthenoid series which of following is wrong statement for Ce ?
A The general oxidation state of Ce is +3 and +4
B +3 oxidation state of Ce is more stable than +4
C +4 oxidation state of Ce is not available in its aqueous solution
D Ce (IV) behave as oxidizing agent

Answer:The general oxidation state of Ce is +3 and +4
15 Lanthanide contraction is caused due to ____
A The appreciable shilding on outer electrons by 4f electrons from the nuclear charge
B The appreciable shilding on outer electrons by 5d electrons from the nuclear charge
C The same effective nuclear charge from Ce to Lu
D The poor shilding on outer electrons by 4f electrons from the nucluear charge

Answer:The poor shilding on outer electrons by 4f electrons from the nucluear charge
16 The actinides exhibit more number of oxidation states in general than the lanthanide, because ____
A The 5f-orbitals are more spread in place than the 4f orbitals
B Energy differnce between 5f and 6d orbitals is less than that of 4f and 5d orbitals
C Energy difference between 5f and 6d orbital is more than that of 4f and 5d orbitals
D Actinides are more reactive than that of lanthanides

Answer: Energy differnce between 5f and 6d orbitals is less than that of 4f and 5d orbitals
17 The general oxidation state of Lanthanide elements is +3. Which of following is incorrect statement for them ?
A Ln (III) hydroxides are mainly basic in character
B Because of the large size of the Ln (III) ions, the bonding in its compounds is ionic in character
C Ln (III) Compounds are generally colourless
D The ionic sizes of Ln (III) decreases with increase in atomic number

Answer:Because of the large size of the Ln (III) ions, the bonding in its compounds is ionic in character
18 Which of following statement is wrong for transition element ?
A Once the d5 configuration nis exceeded the tendency to involve all the 3d electrons in bonding decreases
B In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes
C In the highest oxidation states, the transition metals show basic
D In the highest oxidation states of the first five (transition elements (Sc to Mn) all the 4s & 3d electrons are used for bonding

Answer: In the highest oxidation states, the transition metals show basic
19 Which of following is wrong statement ?
A La (OH)3 is less basic than Lu(OH)3
B In lanthanide series, ionic radius decreases while moving Ce3+ to Lu3+ ion
C La is actually tranusition element
D Due to Lanthanide contraction atomic radius of Zn and Hf are same

Answer: La (OH)3 is less basic than Lu(OH)3
20 What is oxidation no. of Cr in K2 Cr2 O7
A +2
B +4
C +6
D +7

Answer: +2

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