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Some P Block Elements

Q: List -I List -2A. IVA group 1. Crystalline formB. Onyx 2 Amorphous form of silicaC. Lubricant 3. GraphiteD. Hardest material 4.ns2 np25. DiamondThe correct match with A B C D is ?

IV A Group has 4 valence electrons and are arranged as \$ns^2\$ \$np^2\$.Onyx is the amorphous form of silica.Diamond is one of the hardest materials due to the strong covalent bonds which connect various atoms in the lattice.Graphite is used as a lubricant due to the weak bonding between its layers, which allows the layers to slide on one another.

Q: An alkyl halide reacts with a group 14 element \$Y\$ at 570K with \$Cu\$ as a catalyst and produces a dialkyl chloro compound \$Z\$. The compound \$Z\$ on hydrolysis gives another compound which is a strong water repellent and quite inert chemically. The dioxide of \$Y\$ is acidic in nature. The alkyl halide can also be obtained from methane after monosubstitution. Identify \$Y\$ and \$Z\$.

Monosubstitution of methane gives methyl chloride. It reacts at \$570K\$ with \$Si\$ having \$Cu\$ as catalyst to produce \$(CH _{3})_{2} SiCl_{2}\$, which is the compound \$Z\$. \$ (CH _{3})_{2} SiCl_{2}\$ on hydrolysis gives \$ (CH _{3})_{2} Si(OH)_{2}\$, which is a strong water repellent and quite inert chemically. Also \$SiO_2\$ is acidic in nature.Option 'A' is correct.

Q: Match the ores from List-I with their corresponding formulae from List-II.List -I List -IIA. Borax 1) \$Al_{2}O_{3}.2H_{2}O\$B. Razorite 2) \$Ca_{2}B_{6}O_{11}.5H_{2}O\$ C. Bauxite 3) \$Na_{2}B_{4}O_{7}.4H_{2}O\$D.Colemanite 4) \$Na_{2}B_{4}O_{7}.10H_{2}O\$

Borax: \$Na_{2} B_{4} O_{7} .10H_{2} O \$Razorite: \$Na_{2} B_{4} O_{7} .4H_{2} O \$Bauxite: \$Al_{2} O_{3} .2H_{2} O \$Colemanite: \$Ca_{2} B_{6} O_{11} .5H_{2} O \$So, the correct option is 'C'.

Q: The number of \$-OH\$ units directly bonded to boron atoms in borax is:

As can be seen from image 4 −OH units are directly bonded to boron atoms in borax. So, the correct option is B.

Q: The tendency to show inert pair effect follows the order :

Down the group inert pair effect increases so the correct order is \$B < Al < Ga < In < Tl\$.

Q: Which of the following is incorrect regarding the structural features of borax?

It has two tetrahedral and two triangular units. TrueAll the boron atoms are not in same hybrid state. TrueEach boron atom of a pair is tetravalent. TrueIn the structure of borax, none of the boron atoms have lone pairs of electrons.Option D is correct.

Q: Which of the following statement is/are correct?

A) \$B_2H_6\$, diborane is an electron deficient compound. B) Boron has a very strong crystalline lattice. So, it has an extremely high melting point.C) \$BrF_{3} \$ has a bent structure whereas \$BF_{3} \$ has a trigonal planar structure. \$BF_3\$ has coplanar geometry due to \$sp^2\$ hybridisation on boron atom whereas \$BrF_3\$ has \$sp^3d\$ hybridisation and possesses two lone pairs of electron on Br atom which leads to T shaped geometry.D) Ortho boric acid contains triangular \$BO_3^{-3}\$ units.Option B and C are correct.

Q: Order of stability of the ions of Ge, Sn and Pb is:

On moving down group IV A, the stability of the +2 oxidation state increases due to the inert pair effect which becomes more pronounced in heavier elements.Hence, the correct order of the stability of oxidation states is \$Ge^{2+} < Sn^{2+} < Pb^{2+}\$.So, the correct option is ' A'.

Q: Which one of the following statements is incorrect about the structural properties of \$ BF_{3}\$?

\$B{ F }_{ 3 }\$ has a trigonal planar structure, all three \$B-F\$ bonds lie in the same plane. Thus, the p orbitals of Boron and Fluorine become parallel.p-orbital of Boron is empty while fluorine has a lone pair. Fluorine donates its lone pair and this is called back bonding, or \$p\pi -p\pi \$ bond. Resonating structures can be obtained.Since the \$B{ F }_{ 3 }\$ molecule is highly symmetrical, it has no dipole moment. All bonds are of equal length, thus option (B) is correct.In Boron trihalides, the length of \$B-F\$ bond would be shorter than expected for a single bond, due to \$p\pi -p\pi\$ bonding.\$B{ Cl }_{ 3 }\$ is also a trigonal planar molecule. Back bonding does not change the structure of the molecule. It simply decreases bond length \$B-X\$ and decreases Lewis acidity of \$B{ X }_{ 3 }\$.Thus, option \$(D)\$ is incorrect.

Chemistry
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JEE Advanced Easy Qs Med Qs Hard Qs

List -I List -2
A. IVA group   1. Crystalline form
B. Onyx   2 Amorphous form of silica
C. Lubricant 3. Graphite
D. Hardest material   4.ns2 np2
5. Diamond
The correct match with A B C D is ?

2 4 3 5

2 3 5 4

4 2 3 5

5 3 2 4

Hard

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An alkyl halide reacts with a group 14 element $Y$ at 570K with $C u$ as a catalyst and produces a dialkyl chloro compound $Z$ . The compound $Z$ on hydrolysis gives another compound which is a strong water repellent and quite inert chemically. The dioxide of $Y$ is acidic in nature. The alkyl halide can also be obtained from methane after monosubstitution. Identify $Y$ and $Z$ .

Y = S i

and

Z = (C H_{3})_{2} S i C l_{2}

Y = S i

and

Z = C H_{3} C l

Y = C

and

Z = S i C l_{4}

Y = S i

and

Z = C C l_{4}

Hard

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Match the ores from List-I with their corresponding formulae from List-II.

List -I List -II
A. Borax 1) $A l_{2} O_{3} . 2 H_{2} O$
B. Razorite 2) $C a_{2} B_{6} O_{11} . 5 H_{2} O$
C. Bauxite 3) $N a_{2} B_{4} O_{7} . 4 H_{2} O$
D.Colemanite 4) $N a_{2} B_{4} O_{7} . 10 H_{2} O$

A-3, B-4, C-2, D-1

A-2, B-3, C-4, D-1

A-4, B-3, C-1, D-2

A-1, B-2, C-3, D-4

Hard

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The number of $- O H$ units directly bonded to boron atoms in borax is:

Hard

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The tendency to show inert pair effect follows the order :

G a < A l < I n < T l < B

B < A l < G a < I n < T l

B = A l = G a < I n < T l

T l < I n < G a < A l < B

Hard

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Which of the following is incorrect regarding the structural features of borax?

It has two tetrahedral and two triangular units

All the boron atoms are not in same hybrid state

Each boron atom of a pair is tetravalent

Only one boron atom has a lone pair of electrons

Hard

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Which of the following statement is/are correct?

B_{2} H_{6}

is not an electron-deficient compound

Boron has an extremely high melting point because of the strong binding forces in the covalent polymer

B F_{3}

and

B r F_{3}

molecules have different shapes

Ortho boric acid contains pyramidal

B O_{3}^{- 3}

units

Hard

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Order of stability of the ions of Ge, Sn and Pb is:

G e^{2 +} < S n^{2 +} < P b^{2 +}

G e^{4 +} < S n^{4 +} < P b^{4 +}

S n^{4 +} < S n^{2 +}

P b^{2 +} < P b^{4 +}

Hard

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Consider the following reactions:

i) $C r_{2} O_{3} + 2 A l \to A l_{2} O_{3} + 2 C r + h e a t$
ii) $A l_{2} O_{3} + 2 C r \to C r_{2} O_{3} + 2 A l + h e a t$
iii) $2 A l + 6 N a O H \to 2 N a_{3} A l O_{3} + 3 H_{2}$

Out of these, the possible reactions are:

i and iii

ii and iii

i and ii

i , ii and iii

Hard

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Which one of the following statements is incorrect about the structural properties of $B F_{3}$ ?

The unsual shortness of

B - F

bonds is due to

p π - p π

interaction between

B

and

F

atoms

All the three

B - F

bond lengths are equal

Double bond is delocalized giving three resonance structures.

Due to back bonding,

B F_{3}

and

B C l_{3}

are not isostructural molecules

Hard

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Some P Block Elements

Chemistry 4080 Views

List -I List -2 A. IVA group 1. Crystalline form B. Onyx 2 Amorphous form of silica C. Lubricant 3. Graphite D. Hardest material 4.ns2 np2 5. Diamond The correct match with A B C D is ?

Match the ores from List-I with their corresponding formulae from List-II. List -I List -II A. Borax 1) Al2​O3​.2H2​O B. Razorite 2) Ca2​B6​O11​.5H2​O C. Bauxite 3) Na2​B4​O7​.4H2​O D.Colemanite 4) Na2​B4​O7​.10H2​O

The number of −OH units directly bonded to boron atoms in borax is:

The tendency to show inert pair effect follows the order :

Which of the following is incorrect regarding the structural features of borax?

Which of the following statement is/are correct?

Order of stability of the ions of Ge, Sn and Pb is:

Consider the following reactions: i)Cr2​O3​+2Al→Al2​O3​+2Cr+heat ii)Al2​O3​+2Cr→Cr2​O3​+2Al+heat iii)2Al+6NaOH→2Na3​AlO3​+3H2​ Out of these, the possible reactions are:

Which one of the following statements is incorrect about the structural properties of BF3​?

Chemistry
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List -I List -2
A. IVA group 1. Crystalline form
B. Onyx 2 Amorphous form of silica
C. Lubricant 3. Graphite
D. Hardest material 4.ns2 np2
5. Diamond
The correct match with A B C D is ?

Match the ores from List-I with their corresponding formulae from List-II.

List -I List -II
A. Borax 1) $A l_{2} O_{3} . 2 H_{2} O$
B. Razorite 2) $C a_{2} B_{6} O_{11} . 5 H_{2} O$
C. Bauxite 3) $N a_{2} B_{4} O_{7} . 4 H_{2} O$
D.Colemanite 4) $N a_{2} B_{4} O_{7} . 10 H_{2} O$

The number of $- O H$ units directly bonded to boron atoms in borax is:

Consider the following reactions:

i) $C r_{2} O_{3} + 2 A l \to A l_{2} O_{3} + 2 C r + h e a t$
ii) $A l_{2} O_{3} + 2 C r \to C r_{2} O_{3} + 2 A l + h e a t$
iii) $2 A l + 6 N a O H \to 2 N a_{3} A l O_{3} + 3 H_{2}$

Out of these, the possible reactions are:

Which one of the following statements is incorrect about the structural properties of $B F_{3}$ ?