The p-Block Elements Test

Result

The p-Block Elements Test - 59

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

Select the correct order with respect to acidic nature of the given compounds.

A
$$Al_{2}O_{3}< In_{2}O_{3}< Tl_{2}O< B_{2}O_{3}$$

B
$$Tl_{2}O< \, In_{2}O_{3}< Al_{2}O_{3}< B_{2}O_{3}$$

C
$$Al_{2}O_{3}< B_{2}O_{3}< \: In_{2}O_{3}< Tl_{2}O$$

D
$$Tl_{2}O< Al_{2}O_{3}< Br_{2}O_{3}< \: In_{2}O_{3}$$

Solution

As we move from top to bottom in a group, metallic character increases and so the acidic nature of the oxides decreases.
Therefore, $$B_2O_3$$ is acidic in nature, $$Al_2O_3$$ and $$Ga_2O_3$$ are amphoteric in nature, whereas $$In_2O_3$$ and $$Tl_2O$$ are basic in nature.

Hence, the correct order with respect to acidic nature of compounds is as follows:
$$Tl_2O<In_2O_3<Al_2O_3<B_2O_3$$

Hence, option $$B$$ is correct.
Question 2
1 / -0

In representative elements the ionization energy values generally decrease smoothly down the group. But in boron group the values show an erratic trend. This is mainly due to :

A
increase in metallic nature down the group

B
inert pair effect in the heavier elements of the group

C
d-block contraction and lanthanide contraction affecting the values of later elements due to poor shielding by d and f electrons

D
the different type of packing in their crystalline structure

Solution

Poor shielding of nuclear charge in Ga by 3d electrons results in smaller atomic size and higher I.P for the atom. Similarly, in TI the poor shielding by the 4f electrons leads to higher I.P or the atom. Hence, first I.P values for the 3rd group elements show erratic trend.
Question 3
1 / -0

Directions For Questions

$$A$$ is a white crystalline solid. Its aqueous solution is alkaline in nature. It is used in water softening. On heating, it swells up to form a puffy mass, $$B$$. Strong heating of $$B$$ gives $$C$$. Heating of $$C$$ with nickel oxide gives a brown bead, $$D$$.

...view full instructions

The substance 'B' is

A
$$Na_2B_{4}O_{7}$$

B
$$B_{2}O_{3}$$

C
$$H_{3}BO_{3}$$

D
$$HBO_{2}$$

Solution

A is borax or sodium tetraborate $$(Na_2B_4O_7.10H_2O)$$.
One mole of A contains 10 moles of water of crystallization.
It is a white crystalline solid and is used in water softening. Its aqueous solution is alkaline due to the formation of sodium hydroxide upon hydrolysis of $$Na_2B_4O_7$$. The reaction is as follows:

$$Na_2B_4O_7+7H_2O \rightleftharpoons 2NaOH + 4 H_3BO_3$$

When borax is heated, it loses water and swells into a white mass which is 'B'. The formula is $$Na_2B_4O_7$$. The reaction is as follows:

$$Na_2B_4O_7.10H_2O \xrightarrow {heat} \underset {B} {Na_2B_4O_7} + 10H_2O$$

On further heating, 'B' forms glossy solid called borax glass and borax bead (compound C or $$B_2O_3$$). The reaction is as follows:

$$Na_2B_4O_7 \xrightarrow {heat} 2NaBO_2 + \underset {C} {B_2O_3}$$

When 'C' is heated with nickel oxide, a brown bead 'D' is obtained which is nickel metaborate $$(Ni(BO_2)_2)$$. The reaction is as follows:

$$B_2O_3 + NiO \rightarrow \underset {\text{brown bead} \ (D)} {(Ni(BO_2)_2)} $$
Question 4
1 / -0

Alkyl substituted chlorosilane, $$R_{n}SiCl_{(4-n)}$$, on hydrolysis and then condensation polymerisation yields silicones. What is the value of n in the alkyl substituted chlorosilane used for the preparation of cross-linked silicone?

A
1

B
2

C
3

D
4

Solution

$$RSiCl_{3}$$ on hydrolysis gives a cross linked silicone.
Question 5
1 / -0

How many oxygen atoms are shared per $$ SiO_{4}$$ tetrahedral unit in mineral wollastonite $$[Ca_{3}(Si_{3}O_{9})]$$?

A
2

B
3

C
1

D
4

Solution

It is cyclic silicate which has anion $$ Si_{3}O_{9}^{6-}$$.
Two atoms of oxygen are shared per $$SiO_4$$ tetrahedral unit.
Question 6
1 / -0

Name the type of the structure of silicate in which one oxygen atom of $$\left [ SiO_{4} \right ]^{4-}$$ is shared:

A
linear chain silicate

B
sheet silicate

C
pyrosilicate

D
three dimensional silicate

Solution

In pyrosilicate, only one oxygen atom is shared.

Pyrosilicate formula: $$[Si_2O_7]^{6-}$$.

Hence, option C is correct.
Question 7
1 / -0

The chain length of silicone polymer can be controlled by adding:

A
$$MeSiCl_{3}$$

B
$$Me_{2}SiCl_{2}$$

C
$$Me_{3}SiCl$$

D
$$Me_{4}Si$$

Solution

The chain length of silicone polymer can be controlled by adding $$Me_{3}SiCl$$.
$$R \cdot + Me_{3}SiCl \rightarrow Me_{3}Si-R+ Cl \cdot$$
$$2Cl \cdot \rightarrow Cl_2$$
Question 8
1 / -0

Which of the following oxides is acidic in nature?

A
$$B_{2}O_{3}$$

B
$$Al_{2}O_{3}$$

C
$$Ga_{2}O_{3}$$

D
$$In_{2}O_{3}$$

Solution

$$B_{2}O_{3}$$ is acidic and reacts with basic (metallic oxides forming metal borates.

Aluminum and galium oxides are amphoteric and those of indium and thallium are basic in their properties.

Hence, option A is correct.
Question 9
1 / -0

Ammonia gas is not prepared by :

A
reduction of sodium nitrite or sodium nitrate by the reaction of zinc dust and sodium hydroxide.

B
hydrolysis of calcium cyanamide.

C
heating ammoniumchloridewith slaked lime.

D
heating of $$(NH_{4})_{2}Cr_{2}O_{7}$$

Solution

(1) $$NO_{2}^{-}+7[H]^{-}\xrightarrow[]{Zn/NaOH}NH_{3}+2H_{2}O; NO_{3}^{-}+9[H]^{-}\xrightarrow[]{Zn/NaOH}NH_{3}+3H_{2}O$$
(2) $$CaCN_{2} + 3H_{2}O \rightarrow CaCO_{3} + 2NH_{3}$$
(3) $$NH_{4}Cl + Ca(OH)_{2} \rightarrow 2NH_{3} + CaCl_{2} + 2H_{2}O$$
(4) $$(NH_{4})_{2}Cr_{2}O_{7} \rightarrow N_{2} + Cr_{2}O_{3} + 4H_{2}O$$
Question 10
1 / -0

In silicones, the maximum number of silicon atoms directly linked to an oxygen atom is :

A
3

B
4

C
1

D
2

Solution

In every type of silicons a, b, c, maximum number of silicon atom linked to oxygen atom is 2.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

The p-Block Elements Test - 59

Result

The p-Block Elements Test - 59

Score

-

Rank

-

SHARING IS CARING

Question 1

$$Al_{2}O_{3}< In_{2}O_{3}< Tl_{2}O< B_{2}O_{3}$$

$$Tl_{2}O< \, In_{2}O_{3}< Al_{2}O_{3}< B_{2}O_{3}$$

$$Al_{2}O_{3}< B_{2}O_{3}< \: In_{2}O_{3}< Tl_{2}O$$

$$Tl_{2}O< Al_{2}O_{3}< Br_{2}O_{3}< \: In_{2}O_{3}$$

Solution

Question 2

increase in metallic nature down the group

inert pair effect in the heavier elements of the group

d-block contraction and lanthanide contraction affecting the values of later elements due to poor shielding by d and f electrons

the different type of packing in their crystalline structure

Solution

Question 3

$$Na_2B_{4}O_{7}$$

$$B_{2}O_{3}$$

$$H_{3}BO_{3}$$

$$HBO_{2}$$

Solution

Question 4

1

2

3

4

Solution

Question 5

2

3

1

4

Solution

Question 6

linear chain silicate

sheet silicate

pyrosilicate

three dimensional silicate

Solution

Question 7

$$MeSiCl_{3}$$

$$Me_{2}SiCl_{2}$$

$$Me_{3}SiCl$$

$$Me_{4}Si$$

Solution

Question 8

$$B_{2}O_{3}$$

$$Al_{2}O_{3}$$

$$Ga_{2}O_{3}$$

$$In_{2}O_{3}$$

Solution

Question 9

reduction of sodium nitrite or sodium nitrate by the reaction of zinc dust and sodium hydroxide.

hydrolysis of calcium cyanamide.

heating ammoniumchloridewith slaked lime.

heating of $$(NH_{4})_{2}Cr_{2}O_{7}$$

Solution

Question 10

3

4

1

2

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.