Chemical Properties of Boron Family

Q. Which one of the following trihalide does not exist?

1. $BC{l}_3$
2. $BB{r}_3$
3. $Tl{I}_3$
4. $AlC{l}_3$

Q. Among the halides, the order of decreasing lewis acid character is:
$1.BC{l}_3,2.AlC{l}_3,3.GaC{l}_3,4.InC{l}_3$

1. $1>2>3>4$
2. $4>2>3>1$
3. $2>1>3>4$
4. $1<2<3<4$

Q. Which of the following statements is correct about borazine?

1. Borazine is called 'inorganic benzene'
2. Diborane react with ammonia to give borazine
3. Like organic benzene, borazine does not give addition product.
4. Borazine is more reactive than Benzene

Q. Choose the incorret statement regarding borazine.

1. Borazine is called 'inorganic benzene'
2. Diborane react with ammonia to give borazine
3. Like organic benzene, borazine does not give addition product.
4. Borazine is more reactive than Benzene

Q. Which of the following compounds are not hydrolysed?

1. $PbC{l}_4$
2. $SiC{l}_4$
3. $SnC{l}_4$
4. $CC{l}_4$

Q. $B{X}_{3}N{H}_3⟶B{X}_3.N{H}_3$ $\Delta H_f$ = Heat of formation of the adduct. The numerical value of $\Delta H_f$ is found to be maximum for:

1. $B{F}_3$
2. $BC{l}_3$
3. $BB{r}_3$
4. $B{I}_3$

Q. Which one of the following elements of group 13 can react with an alkali to give $H_2$ gas?

1. Boron
2. Aluminium
3. Gallium
4. All of these

Q. $BC{l}_3+N{H}_{4}Cl\stackrel{140{}^{\circ }C}{\to }P$
Which of the following is correct about P?

1. P contains 3 N-H bonds and 3 B-Cl bonds
2. P contains 3 N-H bonds and 3 B-H bonds
3. P contains 3 N-Cl bonds and 3 B-Cl bonds
4. P contains 3 N-Cl bonds and 3 B-H bonds

Q. Pick out the incorrect statement:

1. Group 13 elements have a lower tendency to form complexes than the s- block elements.
2. The tendency to form ionic compounds increases from B to Tl
3. Boron forms covalent compounds only
4. Thallium forms ionic compounds only

Q. Which of the following statements is correct about borazine?

1. Borazine is called 'inorganic benzene'
2. Diborane react with ammonia to give borazine
3. Like organic benzene, borazine does not give addition product.
4. Borazine is more reactive than Benzene

Q.

What is the end product obtained when hydrogen chloride reacts with a metal?

Q. The maximum covlaency for boron and aluminium respectively are

1. 4 for both
2. 6 and 4
3. 4 and 6
4. 6 for both

Q.

Which one of the following mixed sulphates is not an alum ?

1. $K_{2}S{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$

2. $K_{2}S{O}_4.C{r}_2(S{O}_4{)}_3.24H_{2}O$

3. $N{a}_{2}S{O}_4.F{e}_2(S{O}_4{)}_3.24H_{2}O$

4. $CuS{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$

Q. A Boron mineral have pentaborate anion whose molecular formula is $\left[B_5{O}_6\right(OH{)}_4{]}^{-}$. The number of $B-O-B$ linkage present in one molecule of the mineral are

1. $3$
2. $5$
3. $4$
4. $6$

Q.

Among Boron family, the element that forms an amphoteric oxide and amphoteric hydroxide is:

1. B

2. Al

3. Ga

4. In

Q. $ZnO$ is white when cold but yellow when hot:

1. As $ZnO$ is heated, its oxidation state changes
2. Due to polarisation of oxide ions
3. Due to escape of oxide ions in the form of oxygen, the electrons left in the lattice causes colour to appear
4. Due to metal deficiency on heating, holes transit, producing colours

Q.

Which one of the following mixed sulphates is not an alum ?

1. $K_{2}S{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$

2. $K_{2}S{O}_4.C{r}_2(S{O}_4{)}_3.24H_{2}O$

3. $N{a}_{2}S{O}_4.F{e}_2(S{O}_4{)}_3.24H_{2}O$

4. $CuS{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$

Q.

The CsCl type structure is exhibited by alkali halides only when the radius of the cation is large enough to keep touching its eight nearest neighbour anions. Below what minimum ratio of cation to anion radii $\left(\frac{r_{+}}{r_{-}}\right)$ this contact is prevented ?

1. 0.225

2. 0.414

3. 0.632

4. 0.732

Q. All of the group 13 elements form ionic halides except

1. boron
2. thallium
3. gallium

Q. Match the Column-I with Column-II. Choose the correct option among the following
Column – I Column – II
(A) $B{i}^{3+}⟶(BiO{)}^{+}$ (p) Heat

(B) $\left(Al{O}_2^{-}\right)⟶Al(OH{)}_3$ (q) Hydrolysis

(C) $Si{O}_4^{4-}⟶S{i}_2{O}_7^{6-}$ (r) Acidification

(D) $B_4{O}_7^{2-}⟶\left[B\right(OH{)}_3]$ (s) Dilution by water

1. A-(r), B-(q), C-(r), D-(q)
2. A-(q), B-(q, r), C-(p), D-(q, r)
3. A-(q), B-(r), C-(q), D-(p)
4. A-(q), B-(p), C-(q), D-(r)

Q. Which one of the follwing is stable oxidation state of Tl?

1. 1
2. 3
3. 2
4. (b) and (c) above.

Q. The maximum covalent character is seen in which of the following compounds?

1. $B_2{O}_3$
2. $BeO$
3. $CsF$
4. $L{i}_2$

Q. Assertion (A): $Al(OH{)}_3$ is amphoteric in nature.
Reason (R): $Al(OH{)}_3$ is $H^{+}$ donor acid as well as $O{H}^{-}$ donor base.

1. (A) is correct; (R) is correct and (R) correctly explains (A).
2. (A) is correct; (R) is incorrect.
3. (A) is incorrect; (R) is correct.
4. (A) is correct; (R) is correct and (R) doesn't explain (A) correctly.

Q. $B+H_{2}O\to A+C.A\&C$ are as follows.

1. $B(OH{)}_3,H_2$
2. $B_2{O}_3,H_{2}O$
3. $B(OH{)}_3,H_{2}O$
4. $B_2{O}_3,H_2$

Q.

An aqueous solution of potash alum is -

1. Acidic

2. Alkaline

3. Neutral

4. None of these

Q. Among the halides
$i.BC{l}_3$
$ii.AlC{l}_3$
$iii.GaC{l}_3$
$iv.InC{l}_3$
The order of decreasing Lewis acid character is:

1. i, ii, iii, iv
2. ii, iii, iv, i
3. iii, iv, ii, i
4. iv, iii, ii, i

Q. Which of the following oxides are basic?

1. $B_2{O}_3$
2. $T{l}_{2}O$
3. $I{n}_2{O}_3$
4. $A{l}_2{O}_3$

Q.

According to Fajan's Rule, covalent character is most favoured in ______

1. Small cation, large anion

2. Small cation, small anion

3. Large cation, large anion

4. Large cation, small anion

Q. Which among the following boron family element form $A_2{O}_3$ type oxide on heating in air?

1. B
2. Al
3. Neither a nor b
4. Both (a) and (b) above.

Q.

Thallium shows different oxidation states because -

1. Of inert pair effect

2. Of its high reactivity

3. It is a transition metal

4. Of its amphoteric character