The d- and f- Block Elements Test

Result

The d- and f- Block Elements Test - 16

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Transition metals are often paramagnetic owing to:

A
high m.p. and b.p. of transition metals

B
presence of vacant d-orbitals

C
presence of one or more unpaired d-electrons

D
their less electropositive nature as compared to the elements of groups IA and IIA

Solution

The general outer electronic configuration of d-block elements is $$(n-1)d^{1-10}\ ns^{1-2}$$. Hence, d - block elements often have one or more unpaired d - electrons.

Due to presence of these unpaired electrons, transition elements show paramagnetism.

Therefore transition elements are often paramagnetic due to presence of one or more unpaired d electrons.

Option C is correct.
Question 2
1 / -0

Amphoteric behaviour is shown by the oxides of:

A
$$Al$$ and $$Ca$$

B
$$Pb$$ and $$Ba$$

C
$$Cr$$ and $$Mg$$

D
$$Sn$$ and $$Zn$$

Solution

Amphoteric oxides can behave as an acid as well as the base. They react with both acids and bases to form salts. Tin oxide although doesn't dissolve in water but it is amphoteric in nature. Zinc oxide is also amphoteric in nature.

$$ZnO+HCl \rightarrow ZnCl_2+H_2O$$
$$ZnO+NaOH \rightarrow Na_2ZnO_2+H_2O$$

$$SnO_2+HCl \rightarrow SnCl_4+H_2O$$
$$SnO_2+NaOH+H_2O \rightarrow Na_2[Sn(OH)_6]$$

Hence, option D is correct.
Question 3
1 / -0

Stable electronic configuration of a transition metal is:

A
$$1s^{2} 2s^{2}2p^{6} 3s^{2} 3p^{6} 3d^{9} 4s^{2}$$

B
$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{5}$$

C
$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2}$$

D
$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{10} 4p^{6}$$

Solution

Generally, the elements having half-filled and completely filled outer electronic configurations are stable elements.

Here in given options the configuration: $$1s^22s^22p^63s^23p^64s^23d^5$$ contains half filled outer electronic configuration $$(3d^5)$$.

Hence option B is correct.
Question 4
1 / -0

The magnetic moment of $$[Cu(NH_{3})_{4}]^{2+}$$ was found to be 1.73 B.M. The number of unpaired electrons in the complex is:

A
0

B
1

C
2

D
3

Solution

Magnetic moment of a complex having n-unpaired electrons is given by: $$\sqrt{n(n+2)}$$, where $$n$$ is the number of unpaired electrons.

$$\sqrt{n(n+2)}= 1.73$$

$$\therefore$$ $$n=1$$.
Question 5
1 / -0

Potassium dichromate can be prepared by:

A
heating $$Na_{2}Cr_2O_{7}$$ solution with $$KCl$$ solution and then cooling.

B
heating powdered chromite ore with quicklime in the presence of air

C
heating $$K_{2}CrO_{4}$$ with sulphuric acid

D
both $$A$$ and $$C$$

Solution

Potassium dichromate is usually prepared by the reaction of potassium chloride on sodium dichromate.
$$Na_{2}Cr_{2}O_{7}+2KCl \rightarrow K_{2}Cr_{2}O_{7}+2NaCl$$

It can also be prepared by heating $$K_{2}CrO_{4}$$ with $$H_{2}SO_{4}$$.
$$2K_{2}CrO_{4}+2H^+ \rightarrow K_{2}Cr_{2}O_{7}+2K^++H_{2}O$$

Hence, option D is correct.
Question 6
1 / -0

The starting element in the incomplete period of long form of periodic table

A
$$Cs$$

B
$$Rn$$

C
$$Fr$$

D
$$Th$$

Solution

The incomplete period in the periodic table is seventh period and the first element in the seventh period is francium, atomic number 87.
Question 7
1 / -0

The correct order of atomic radii is:

A
$$Yb^{3+}< Pm^{3+}< Ce^{3+}< La^{3+}$$

B
$$Ce^{3+}< Yb^{3+}< Pm^{3+}< La^{3+}$$

C
$$Yb^{3+}< Pm^{3+}< La^{3+}< Ce^{3+}$$

D
$$Pm^{3+}< La^{3+}< Ce^{3+}< Yb^{3+}$$

Solution

Ionic radii decrease as we move across the lanthanide series due to lanthanide contraction.

As all ions are in $$+3$$ oxidation state, ionic radii will follow the trend of atomic radii:
$$Yb^{3+}< Pm^{3+}< Ce^{3+}< La^{3+}$$

(Atomic number of $$La = 57, Ce = 58, Pm = 61, Yb = 70$$)

Hence, option A is correct.
Question 8
1 / -0

An atom of element has $$2K, 8L$$ and $$3M$$ electrons. Then the element belongs to :

A
IA group

B
IIA group

C
IIIA group

D
IVA group

Solution

The total number of electrons present in all the shells are $$2+8+3=13$$, hence the atomic number of element is $$13$$ and the electronic configuration would be $$1s^22s^22p^63s^23p^1 $$. Element belongs to $$|||A$$ group.
Question 9
1 / -0

Match list-I with a list -II.
List I List II
(A) Lanthanide contraction (p) s-block
(B) Diagonal relationship (q) Elements of 3rd period
(C) Typical elements (r) f-block
(D) Inner transition elements (s) Be-Al

A
A - r, B - s, C - q, D - r

B
A - p, B - r, C - s, D - q

C
A - s, B - q, C - p, D - r

D
A - q, B - p, C - r, D - s

Solution

A) Higher z-effective is experienced by f-block elements due to the poor shielding effect of f-electrons. Thus f-block elements experience lanthanide contraction.

B) Be and Al have equal charge densities. The chemical properties of elements depend upon their charge density. Thus they have similar chemical properties. So, Be and Al shows a diagonal relationship.

C) 3rd-period elements are known as typical elements.

D) f-block elements are known as inner-transition elements as f-block elements are placed in between transition elements.

Hence, option A is the correct match.
Question 10
1 / -0

Iron sheets are covered with a layer of zinc i.e., galvanized mainly to:

A
harden the surface

B
increase the surface

C
prevent action of water only

D
prevent action of oxygen and water

Solution

Iron sheets are covered with a layer of Zinc i.e. galvanized mainly to prevent action of oxygen and water.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

The d- and f- Block Elements Test - 16

Result

The d- and f- Block Elements Test - 16

Score

-

Rank

-

SHARING IS CARING

Question 1

high m.p. and b.p. of transition metals

presence of vacant d-orbitals

presence of one or more unpaired d-electrons

their less electropositive nature as compared to the elements of groups IA and IIA

Solution

Question 2

$$Al$$ and $$Ca$$

$$Pb$$ and $$Ba$$

$$Cr$$ and $$Mg$$

$$Sn$$ and $$Zn$$

Solution

Question 3

$$1s^{2} 2s^{2}2p^{6} 3s^{2} 3p^{6} 3d^{9} 4s^{2}$$

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{5}$$

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2}$$

$$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{10} 4p^{6}$$

Solution

Question 4

0

1

2

3

Solution

Question 5

heating $$Na_{2}Cr_2O_{7}$$ solution with $$KCl$$ solution and then cooling.

heating powdered chromite ore with quicklime in the presence of air

heating $$K_{2}CrO_{4}$$ with sulphuric acid

both $$A$$ and $$C$$

Solution

Question 6

$$Cs$$

$$Rn$$

$$Fr$$

$$Th$$

Solution

Question 7

$$Yb^{3+}< Pm^{3+}< Ce^{3+}< La^{3+}$$

$$Ce^{3+}< Yb^{3+}< Pm^{3+}< La^{3+}$$

$$Yb^{3+}< Pm^{3+}< La^{3+}< Ce^{3+}$$

$$Pm^{3+}< La^{3+}< Ce^{3+}< Yb^{3+}$$

Solution

Question 8

IA group

IIA group

IIIA group

IVA group

Solution

Question 9

A - r, B - s, C - q, D - r

A - p, B - r, C - s, D - q

A - s, B - q, C - p, D - r

A - q, B - p, C - r, D - s

Solution

Question 10

harden the surface

increase the surface

prevent action of water only

prevent action of oxygen and water

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.