DF BLOCK

Question 1

Which of the following 3d metal ion will give lowest enthalpy of hydration when dissolved in water?
1) Cr(2+)
2) Mn(2+)
3) Fe(2+)
4) Co(2+)

Answer 1

Mn(2+)

Question 2

German silver is an alloy of

Answer 2

Zinc,copper and nickel

Question 3

Caste iron is used to manufacture wrought iron(True or False)

Answer 3

True

Question 4

Bronze is an alloy of

Answer 4

Copper and Tin

Question 5

Gun metal is also known as

Answer 5

Red brass which is a type of bronze

Question 6

Composition of gun metal

Answer 6

Cu, Sn, Zn

Question 7

Is Mn3O4 magnetic?

Answer 7

Yes

Question 8

Common positive oxidation states of chromium?

Answer 8

+2, +3, +6

Question 9

Which of the following has positive electrode potential?(M2+/M)
1)Co
2)Zn
3)Cu
4)Fe

Answer 9

Cu

Question 10

Density order of Cr, Fe,Co,Cu,Zn?

Answer 10

Zn<Cr<Fe<Co<Cu

Question 11

Electronic configuration of Pt

Answer 11

[Xe]4f(14) 5d(9) 6s(1)

Question 12

Melting of Ag is greater than Cs(T/F)

Answer 12

True

Question 13

Interstitial compounds are chemically reactive

Answer 13

False

Question 14

Interstitial compounds have metallic conductivity

Answer 14

True

Question 15

Interstitial compounds are very hard

Answer 15

True

Question 16

Interstitial compounds have high melting points

Answer 16

True

Question 17

Order of first ie of Ti, Mn, Ni, Zn

Answer 17

Ti <Mn<Ni<Zn

Question 18

Transition element having lowest enthalpy of atomisation?
1) V
2) Zn
3) Fe
4) Cu

Answer 18

Zn

Question 19

Zn metal and NaOH produce H2 gas(t/f)

Answer 19

True

Question 20

Cu metal and conc HNO3 produce H2 gas

Answer 20

False

Question 21

Au metal in presence of NaCN produce H2 gas

Answer 21

False

Question 22

Fe metal and conc HNO3 produce H2 gas?

Answer 22

False

Question 23

Which of the following species is stable in aqueous solution?
1) Cr(2+)
2) MnO4(2-)
3) MnO4(3-)
4) Cu+

Answer 23

MnO4(2-)

Question 24

Colour of KMnO4 is due to?

Answer 24

L–> M charge transfer transition

Charge transfer from O to Mn which temporarily reduces oxidation of Mn from +7 to +6

Question 25

A pink coloured solution turns blue on heating. Presence of which cation?

Answer 25

Co(2+)

Question 26

Stability in aqueous solution
Co(3+) <Fe(3+)<Cr(3+)<Sc(3+)

Answer 26

True

Question 27

Highest value for E of M3+/M2+
1 Co
2Cr
3Mn
4Fe

Answer 27

Co

Question 28

Ferrous oxide is more basic, less volatile, more ionic and less easily hydrolysed than ferric oxide

Answer 28

True

Question 29

Colour absorbed by aqueous solution of CuSO4

Answer 29

Orange red

Question 30

CeO2 can be used for oxidation of aldehydes and ketones

Answer 30

True

Question 31

Aqueous solution of EuSO4 is a strong reducing agent.

Answer 31

True

Question 32

Size of Bk(3+) ion is less than Np(3+) ion.

Answer 32

True
Due to actinoid contraction

Question 33

Holmium electronic configuration

Answer 33

Xe 4f(11) 6s(2)

Question 34

Electronic configuration of Np

Answer 34

[Rn]5f(4) 6d(1) 7s(2)

Question 35

Gadolinium electronic configuration

Answer 35

[Xe]4f(7) 5d(1) 6s(2)

Question 36

Order of atomic sizes

Answer 36

Ce>Sn>Yb>Lu

Question 37

Increasing order on ionic radii of trivalent ions
Yb<Pm<Ce<La

Answer 37

True

Question 38

Bonding in compounds of Ln(III) ions is predominantly ionic

Answer 38

True

Question 39

Mo and W have similar atomic radii

Answer 39

True

Question 40

Highest oxidation states of Uranium and Plutonium are 6 and 7 respectively

Answer 40

True

Question 41

Eu doesn’t show +4 oxidation state

Answer 41

True

Question 42

S1: HgS doesn’t dissolve in hot Dil HNO3
S2: PbS, CuS and CdS dissolve in hot Dil HNO3

Answer 42

Both are true

Question 43

Conc HCl + KMnO4 gives Cl2 at room temperature

Answer 43

True

Question 44

Silver nitrate leaves behind a metal on strong heating

Answer 44

True