p-Block Elements — Page 7 | NEET Chemistry

Q61

Match the following : <br><br> <table class=tg> <tbody><tr> <th class=tg-eqm3>

List - I		List - II
(a)	Pure nitrogen</th> <th class=tg-eqm3>	(i)	Chlorine</th> </tr> <tr> <td class=tg-eqm3>
(b)	Haber process</td> <td class=tg-eqm3>	(ii)	Sulphuric acid</td> </tr> <tr> <td class=tg-eqm3>
(c)	Contact process</td> <td class=tg-eqm3>	(iii)	Ammonia<br></td> </tr> <tr> <td class=tg-eqm3>
(d)	Deacon’s process</td> <td class=tg-eqm3>	(iv)	Sodium azide or Barium azide</td> </tr> </tbody></table> <br><br>Which of the following is the correct option?

A <table class=tg> <tbody><tr> <th class=tg-amwm>(a)</th> <th class=tg-amwm>(b)</th> <th class=tg-amwm>(c)</th> <th class=tg-amwm>(d)</th> </tr> <tr> <td class=tg-baqh>(iii)</td> <td class=tg-baqh>(iv)</td> <td class=tg-baqh>(ii)</td> <td class=tg-baqh>(i)</td> </tr> </tbody></table>

B <table class=tg> <tbody><tr> <th class=tg-amwm>(a)</th> <th class=tg-amwm>(b)</th> <th class=tg-amwm>(c)</th> <th class=tg-amwm>(d)</th> </tr> <tr> <td class=tg-baqh>(iv)</td> <td class=tg-baqh>(iii)</td> <td class=tg-baqh>(ii)</td> <td class=tg-baqh>(i)</td> </tr> </tbody></table>

C <table class=tg> <tbody><tr> <th class=tg-amwm>(a)</th> <th class=tg-amwm>(b)</th> <th class=tg-amwm>(c)</th> <th class=tg-amwm>(d)</th> </tr> <tr> <td class=tg-baqh>(i)</td> <td class=tg-baqh>(ii)</td> <td class=tg-baqh>(iii)</td> <td class=tg-baqh>(iv)</td> </tr> </tbody></table>

D <table class=tg> <tbody><tr> <th class=tg-amwm>(a)</th> <th class=tg-amwm>(b)</th> <th class=tg-amwm>(c)</th> <th class=tg-amwm>(d)</th> </tr> <tr> <td class=tg-baqh>(ii)</td> <td class=tg-baqh>(iv)</td> <td class=tg-baqh>(i)</td> <td class=tg-baqh>(iii)</td> </tr> </tbody></table>

Correct Answer

Option B

Solution

Pure N 2 : BaN 3 $\to$ Ba + N 2 Haber process : N 2 + 3H 2 $\to$ 2NH 3 Contact process : 2SO 2 + O 2 $\to$ 2SO 3 Deacon’s process : HCl + O 2

\overset{{CuC{l_2}}}\longrightarrow

H 2 O + Cl 2

Q62

Which of the following statements is not true for halogens?

A All are oxidizing agents.

B All form monobasic oxyacids.

C All but fluorine show positive oxidation states.

D Chlorine has the highest electron-gain enthalpy.

Correct Answer

Option C

Solution

All halogens show both positive and negative oxidation states while fluorine shows only negative oxidation state except due to high electronegativity and small size, F forms only one oxoacid, HOF known as Fluoric (I) acid.

Oxidation number of F is +1 in HOF.

Q63

Which one of the following elements is unable to form MF 6 3– ion?

A Ga

B Al

C B

D In

Correct Answer

Option C

Solution

Boron does not have vacant d-orbitals in its valence shell, so it cannot extend its covalency beyond 4. i.e., ‘B’ cannot form the ions like MF 6 3– .

Q64

Match the interhalogen compounds of column-I with the geometry in column-II and assign the correct code. <br><br> <table class=tg> <tbody><tr> <th class=tg-de48 colspan=2>Column ${\rm I}$ </th> <th class=tg-ujoh></th> <th class=tg-de48 colspan=2>Column ${\rm I}$ ${\rm I}$ </th> </tr> <tr> <td class=tg-pjk9>

List - I		List - II
(A)	</td> <td class=tg-wv9z>XX'</td> <td class=tg-cyim></td> <td class=tg-pjk9>	(i)	</td> <td class=tg-wv9z>T-shape</td> </tr> <tr> <td class=tg-pjk9>
(B)	</td> <td class=tg-wv9z>XX'<sub>3</sub></td> <td class=tg-cyim></td> <td class=tg-pjk9>	(ii)	</td> <td class=tg-wv9z>Pentagonal bipyramidal</td> </tr> <tr> <td class=tg-pjk9>
(C)	</td> <td class=tg-wv9z>XX'<sub>5</sub></td> <td class=tg-cyim></td> <td class=tg-pjk9>	(iii)	</td> <td class=tg-wv9z>Linear</td> </tr> <tr> <td class=tg-pjk9>
(D)	</td> <td class=tg-wv9z>XX'<sub>7</sub></td> <td class=tg-cyim></td> <td class=tg-pjk9>	(iv)	</td> <td class=tg-wv9z>Square pyramidal</td> </tr> <tr> <td class=tg-cyim></td> <td class=tg-cyim></td> <td class=tg-cyim></td> <td class=tg-cyim>
()		(v)	</td> <td class=tg-wrg0>Tetrahedral</td> </tr> </tbody></table>

A (A)

\to

(iii); (B)

\to

(i); (C)

\to

(iv); (D)

\to

(ii)

B (A)

\to

(v); (B)

\to

(iv); (C)

\to

(iii); (D)

\to

(ii)

C (A)

\to

(iv); (B)

\to

(iii); (C)

\to

(ii); (D)

\to

(i)

D (A)

\to

(iii); (B)

\to

(iv); (C)

\to

(i); (D)

\to

(ii)

Correct Answer

Option A

Solution

XX' $\to$ Linear (e.g.

ClF, BrF) XX 3 ' $\to$ T-Shape (e.g.

ClF 3 , BrF 3 ) XX 5 ' $\to$ Square pyramidal (e.g.

BrF 5 , IF 5 ) XX 7 ' $\to$ Pentagonal bipyramidal (e.g.

IF 7 )

Q65

It is because of inability of ns 2 electrons of the valence shell to participate in bonding that

A Sn 2+ is oxidising while Pb 4+ is reducing

B Sn 2+ and Pb 2+ are both oxidising and reducing

C Sn 4+ is reducing while Pb 4+ is oxidising

D Sn 2+ is reducing while Pb 4+ is oxidising

Correct Answer

Option D

Solution

The inertness of s-subshell electrons towards bond formation is known as inert pair effect.

This effect increases down the group thus, for Sn, +4 oxidation state is more stable, whereas, for Pb, +2 oxidation state is more stable, i.e., Sn 2+ is reducing while Pb 4+ is oxidising

Q66

In which pair of ions both the species contain S

-

S bond?

A S 4 O 6 2

-

, S 2 O 3 2

-

B S 2 O 7 2

-

, S 2 O 8 2

-

C S 4 O 6 2

-

, S 2 O 7 2

-

D S 2 O 7 2

-

, S 2 O 3 2

-

Correct Answer

Option A

Solution

S 4 O 6 2– and S 2 O 3 2– have S—S bond.

Q67

AlF 3 is soluble in HF only in presence of KF. It is due to the formation of

A K 3 [AlF 3 H 3 ]

B K 3 [AlF 6 ]

C AlH 3

D K[AlF 3 H]

Correct Answer

Option B

Solution

AlF 3 is insoluble in anhydrous HF because the F – ions are not available in hydrogen bonded HF but, it becomes soluble in presence of little amount of KF due to formation of complex, K 3 [AIF 6 ].

AIF 3 + 3KF $\to$ K 3 [AIF 6 ].

Q68

Boric acid is an acid because its molecule

A contains replaceable H + ion

B gives up a proton

C accepts OH

-

from water releasing proton

D combines with proton from water molecule.

Correct Answer

Option C

Solution

Boric acid behaves as a Lewis acid, by accepting a pair of electrons from OH – ion of water thereby releasing a proton.

H-OH+B(OH) 3 $\to$ [B(OH) 4 ] – + H +

Q69

Among the following the correct order of acidity is

A HClO 2 < HClO < HClO 3 < HClO 4

B HClO 4 < HClO 2 < HClO < HClO 3

C HClO 3 < HClO 4 < HClO 2 < HClO

D HClO < HClO 2 < HClO 3 < HClO 4

Correct Answer

Option D

Solution

The acidic character of the oxoacids increases with increase in oxidation number of the halogen atom i.e., HClO < HClO 2 < HClO 3 < HClO 4 Since the stability of the anion decreases in the order.

ClO 4 - > ClO 3 - > ClO 2 - > ClO – Acid strength also decreases in the same order.

Q70

Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules?

A Br 2 > I 2 > F 2 > Cl 2

B F 2 > Cl 2 > Br 2 > I 2

C I 2 > Br 2 > Cl 2 > F 2

D Cl 2 > Br 2 > F 2 > I 2

Correct Answer

Option D

Solution

Bond dissociation enthalpy decreases as the bond distance increases from F2 to I2.

This is due to increase in the size of the atom, on moving from F to I.

F – F bond dissociation enthalpy is smaller then Cl – Cl and even smaller than Br – Br.

This is because F atom is very small and hence the three lone pairs of electrons on each F atom repel the bond pair holding the F-atoms in F 2 molecules.

The order of bond dissociation enthalpy is : Cl 2 > Br 2 > F 2 > I 2