InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
`(Me)_(2) SiCl_(2)` on hydrolysis will produce.A. `(Me)_(2)Si(OH)_(2)`B. `(Me)_(2)Si = O`C. .D. `Me_(2)SiCl(OH)` |
| Answer» Correct Answer - C | |
| 2. |
Boric acid is used in carrom boards for smooth gliding of pawns becauseA. `H_(3)BO_(3)` molecules ar loosely chemically bonded and hence soft.B. Its low density makes its fluffy.C. It si chemically inert with plywood.D. H-bonding in `H_(3)BO_(3)` give it a layered structure. |
| Answer» Correct Answer - A | |
| 3. |
Boric acid is polymeric due to : |
|
Answer» Correct Answer - Hydrogen Hydrogen |
|
| 4. |
Boric acid is weak monobasic acid and acts as Lewis acid |
|
Answer» Correct Answer - C Assertion `(A)` is true , Reason `( R)` is false. `B(OH)_(3) + H_(2) O rarr [B(OH)_(4)]^(Ө) + H^(oplus)` `H_(3) BO_(3)` is a monobasic weak Lewis acid. |
|
| 5. |
Alumina is. |
|
Answer» Correct Answer - Bad Bad |
|
| 6. |
Alumina is not used as :A. Refractory materialB. A medium in chromatographyC. AbrasiveD. White pigment |
| Answer» Correct Answer - D | |
| 7. |
On strong heating boric acid yieldsA. BB. `B_(2)`C. `B_(2)O_(3)`D. `B_(2)H_(6)` |
|
Answer» Correct Answer - C `2B (OH)_(3) overset(Delta)rarr B_(2)O_(3) +3H_(2)O`. |
|
| 8. |
What is not true about borax ?A. Molecular formula is `Na_(2)B_(4)O_(7). 10H_(2)O`.B. Crystallic borax contains tetranuclear unit of `[B_(4)O_(5)(OH)_(4)]^(2-)`.C. It hydrolyses to give an acidic solution.D. White crystalline solid. |
|
Answer» Correct Answer - C `Na_(2)B_(4)O_(7) +7H_(2) O rarr underset(underset("base")("Strong"))(2NaOH) + underset(underset("acid")("Weak"))(4B(OH)_(3))` On hydrolysis, an alkaline solution is formed. |
|
| 9. |
The electrolysis of pure alumina is not feasible because of its _____ nature. |
|
Answer» Correct Answer - Volatile Volatile |
|
| 10. |
Borazole is aromatic is nature. Nitrigen contributes `pi` - electrons to the system. |
| Answer» Correct Answer - A | |
| 11. |
Which of the following is acidic in nature ?A. `Be(OH)_(2)`B. `Mg(OH)_(2)`C. `Al(OH)_(3)`D. `B(OH)_(3)` |
|
Answer» Correct Answer - D `Mg(OH)_(2)` is a weak base , `Be(OH)_(2)` and `Al(OH)_(3)` are amphoteric in nature. `B(OH)_(3)` can accept one hydroxyl ion from water `(H_(2)O)` and proton is released. Thus, it acts as a Lewis acid. `B(OH)_(3) + 2H_(2)O hArr [B(OH)_(4)]^(Ө) + H_(3)O^(oplus)`. |
|
| 12. |
Boron with hydrogen forms a number of hydrides which are known are boranes. These hydrides are classified into closoboranes and nidobarances. The simplest hydride of boron is diborane. Boron apart from having `(2c, 2e)` bonds also contain `(3c, 2e)` bonds. Boron in diborane is___hydridised.A. `sp`B. `sp^(2)`C. `sp^(3)`D. `dsp^(2)` |
| Answer» Correct Answer - C | |
| 13. |
Boron with hydrogen forms a number of hydrides which are known are boranes. These hydrides are classified into closoboranes and nidobarances. The simplest hydride of boron is diborane. Boron apart from having `(2c, 2e)` bonds also contain `(3c, 2e)` bonds. Boron in diborane is___hydridised. |
|
Answer» Correct Answer - F In diborane, `B` atoms are `sp^(3)` hybridised. |
|
| 14. |
Boron with hydrogen forms a number of hydrides which are known are boranes. These hydrides are classified into closoboranes and nidobarances. The simplest hydride of boron is diborane. Boron apart from having `(2c, 2e)` bonds also contain `(3c, 2e)` bonds. General formula of closoboranes is.A. `B_(n)H_(n+2)`B. `B_(n)H_(n+6)`C. `B_(n)H_(n+2)`D. `B_(n)H_(n+4)` |
| Answer» Correct Answer - A | |
| 15. |
Boron with hydrogen forms a number of hydrides which are known are boranes. These hydrides are classified into closoboranes and nidobarances. The simplest hydride of boron is diborane. Boron apart from having `(2c, 2e)` bonds also contain `(3c, 2e)` bonds. General formula of nidoboranes is.A. `B_(n)H_(n+4)`B. `B_(n)H_(n+6)`C. `B_(n)H_(n+2)`D. `B_(n)H_(n-4)` |
| Answer» Correct Answer - A | |
| 16. |
Gallium is _____ block element. |
|
Answer» Correct Answer - p p |
|
| 17. |
Gallium has smaller atomic radius than aluminium because ofA. Poor shielding power of `d` electrons of `Ga` atomB. Poor shielding power of `s` electrons of `Ga` atomC. Greater shielding power of `s` electrons of `Al` atomD. Greater shielding power `d` electrons of `Ga atom. |
| Answer» Correct Answer - A::B::C | |
| 18. |
Possible oxidation states of boron family elements are :A. `+1`B. `+2`C. `+3`D. `+4` |
| Answer» Correct Answer - A::C | |
| 19. |
Boron cannot expand its covalency beyond three due to _____. |
|
Answer» Correct Answer - Absence of d-orbitals Absence of d-orbitals |
|
| 20. |
Unlike ordinary fire, thermite reaction cannot be stopped by pouring water. Explain. |
|
Answer» During ordinary fire, water not only decreases the temperature of the buring material but also cuts off the supply of `O_(2)` (air). Consider the thermite reaction, `2Al + Fe_(2)O_(3) overset(Delta) rarr Al_(2) O_(3) + 2Fe` In this reaction, the fire cannot be stopped by pouring water because. (a) The oxygen required for the reaction is supplied by the metal oxide, i.e. `Al_(2) O_(3)` , therefore, cutting off the supply of atmosphere `O_(2)` has no effect. (b) At high temperature `(~1270-1300 K), Al` reacts with `H_(2)O` to produce `H_(2)` gas which being inflammable helps in spreading fire rather than extinguishing it. `2 Al + 3H_(2) O rarr Al_(2) O_(3) + 3H_(2) uarr`. |
|
| 21. |
Which of the following metals are extracted by using `Al` as reducing agent ?A. `Na` from `Na_(2)O`B. `Cr` from `Cr_(2)O_(3)`C. `W` from `WO_(3)`D. `Mg` from `MgO` |
| Answer» Correct Answer - B::C | |
| 22. |
Which of the following statements are correct for `Al` ?A. Bad conductor of electricityB. Malleable and ductileC. Found free in natureD. Alloys of `Al` are light |
| Answer» Correct Answer - B::D | |
| 23. |
The members of `B_(n)H_(n+4)` series are less stable than `B_(n)H_(n+6)` series. |
|
Answer» Correct Answer - F Members of `B_(n) H_(n+6)` series are less stable than `B_(n)H_(n+4)` series. |
|
| 24. |
In the following reaction. `2X + B_(2)H_(6) rarr [BH_(2)(X)_(2)]^(oplus) [BH_(4)]^(Ө)` The amine `(s) x` is /are.A. `NH_(3)`B. `CH_(3)NH_(2)`C. `(CH_(3))_(2) NH`D. `(CH_(3))_(3) N` |
| Answer» `3^@` Amines, i.e. `(CH_(3)_(3) N` does not have H-atom attached to N-atom, hence it cannot form `[BH_(4)]^(Ө)` ion. | |
| 25. |
`Tl(III)` salt undergoes disproportionation. |
|
Answer» Correct Answer - F In `Tl`, due to inert pair effect, `+3` oxidation state is less stable and `Ti^(3+)` gets reduced to `Tl^(oplus)`. |
|
| 26. |
The `pH` an aqueous solution of `Al^(3+)` is likely to be.A. NeutralB. AcidicC. Slightly basicD. Highly basic |
|
Answer» Correct Answer - option 4 The hydrolysis of `Al^(3+)` salts gives `Al(OH)_(3)`, which is a weak base and hence `pH` is slightly basic. |
|
| 27. |
Which of the following compounds (s) undergo disproportionation in aqueous solution ?A. `TlCl_(3)`B. `GaCl`C. `InCL`D. `TlCl` |
|
Answer» Correct Answer - B::C Group `13` elements can exhibit `+1` and `+3` oxidation states due to the inert pair effect. Stability of `+1` oxidation state increases down the group, i.e. `TiCl` will be a stable and will undergo disproportionation. |
|
| 28. |
Boric acid is prepared from borax by the action of.A. `HCl`B. `NaOH`C. `CO_(2)`D. `H_(2)SO_(4)` |
|
Answer» Correct Answer - A::D `Na_(2)B_(4)O_(7) +2HCl +5H_(2)O rarr 2NaCl + 4H_(3)BO_(3)` `Na_(2)B_(4)O_(7) + H_(2)SO_(4) + 5H_(2)O rarr Na_(2)SO_(4) + 4H_(3)BO_(3)`. |
|
| 29. |
Which of the following are incorrect statements ?A. `BH_(3)` is a stabel compoundB. Boron hydrides are readily hydrolysedC. Boron hydrides are formed by the reation of `Mg_(3)B_(2)` and dil `HCl`.D. All `B-H` bonds in `B_(2)H_(6)` are equal. |
|
Answer» Correct Answer - A::D `BH_(3)` being an electron-deficient compound is unstable and forms `B_(2)H_(6)`. In `B_(2)H_(6)`, four `B-H` bonds are equal and two `B-H` bonds have equal bend length. |
|
| 30. |
Which of the following minerals contain aluminium ?A. FluorsparB. FeldsparC. MicaD. Carborundum |
|
Answer» Correct Answer - B::C Mica, `K_(2) O.3Al_(2) O_(3).6SiO_(2).2H_(2) O` , Carborundum, `Al_(2) O_(3)`. |
|
| 31. |
State with balanced equations, what happens when aluminium is reacted with hot concentrated caustic soda solution. |
|
Answer» Hydrogen gas is evolved. `2Al +2H_(2)O + 2NaOH overset(Delta)rarr 2NaAlO_(2) + 3H_(2) uarr`. |
|
| 32. |
State the conditions under which the preparation of aluminium is carried out. Give the necessary equations which need not be balanced. |
|
Answer» `Al + NaOH overset("Aqeous")rarrNaAlO_(2) + H_(2)O` `NaAlO_(2) overset(CO_(2))rarr Al(OH)_(3) + Na_(2)CO_(3)` `Al(OH)_(3) overset(Delta)rarr underset("Alumina")(Al_(2)O_(3))+ H_(2)O`. |
|
| 33. |
Aluminium carbide on hydrolysis producesA. Acetylene gasB. Methane gasC. Carbon dioxide gasD. All of the above |
|
Answer» Correct Answer - B `Al_(4)C_(3) + 12H_(2) O rarr 4Al(OH)_(3) + 3CH_(4)`. |
|
| 34. |
What is the value of `x` in the silicate mineral, `Be_(3)Al_(2)Si_(x) O_(18)` ? |
|
Answer» Correct Answer - `(6)` `Be_(3)Al_(2)Si_(6)O_(18)`. |
|
| 35. |
How many orbitals of boron are involved in the hybridisation in `B_(2)H_(6)` ? |
|
Answer» Correct Answer - `(4)` Boron in `B_(2) H_(6)` is `sp^(3)` hybridised and hence four orbitals are involved. |
|
| 36. |
How is boron obtained from borax ? Give the chemical reactions involved. Draw the structure of `B_(2)H_(6)` and give its reaction with `HCl`. |
|
Answer» The finely ground borax is heated with concentrated hydrrochloric acid or concentrated sulphuric acid when sparingly soluble orthoboric acid separates out. `Na_(2)B_(4) O_(7) + 2HCl to 2NaCl + H_(2)B_(4)O_(7)` `Na_(2)B_(4)O_(7) + H_(2)SO_(4) to Na_(2)SO_(4) + H_(2)B_(4)O_(7)` `H_(2)B_(4)O_(7) + 5H_(2)O to 4H_(3)BO_(3)` Orthoboric acid is strongly heated to get `B_(2)O_(3)`. `2H_(3)BO_(3) to B_(2)O_(3) + 3H_(2)O` The reduction of boric anhydride `(B_(2)O_(3))` can be done with sodium, potassium or magnesium. `B_(2)O_(3) + 6K to 2B + 3K_(2)O` `B_(2)O_(3) + 3Mg to 2B + 3MgO` Boron is obtained these days by the electrolysis of a fused mixture containing boric anhydride magnesium oxide and magnesium fluoride. The electrolysis is done in carbon crucible which acts as the anode and iron rod is used as the cathode. The magnesium discharge at the cathode reduces `B_(2)O_(3)` to boron. The structure of diborane is as follows : `B_(2)H_(6)+HCl to underset("Chlorodiborane")(B_(2)H_(5)Cl)+ H_(2)`. |
|
| 37. |
White hybrid state of boron best explains the structures in `B_(2)H_(6)` ?A. `sp^(2)`B. `sp^(3)`C. `dsp^(2)`D. `sp` |
| Answer» Correct Answer - B | |
| 38. |
The chief impurity present in bauxite isA. `SiO_(2)`B. `Fe_(2)O_(3)`C. `K_(2)SO_(4)`D. `NaF` |
| Answer» Correct Answer - B | |
| 39. |
Alum helps in purifying water by :A. Formation `Si` complex with clay particles.B. Sulphate part which combines with the dirt and removes it.C. Aluminium which coagulates the mud particles.D. Making the mud water soluble. |
| Answer» Correct Answer - C | |
| 40. |
Which excess of `NaOH` solution is added in potash alum the product is.A. A bluish precipitateB. Clear solutionC. White precipitateD. Greenish precipitate |
|
Answer» Correct Answer - B Potash alum is `K_(2)SO_(4).Al_(2)(SO_(4))_(3).24 H_(2) O`. `Al_(2)(SO_(4))_(3)` reacts with `NaOH` to form `NaAlO_(2)` which is soluble. `K_(2)SO_(4)` and `Na_(2)SO_(4)` are also soluble and thus a clear solution is obtained in water. `Al_(2)(SO_(4))_(3) +6NaOH rarr 2Al(OH)_(3) +3 Na_(2)SO_(4)` `Al(OH)_(3) +NaOH rarr underset("Soluble")(NaAlO_(2)) + 2H_(2)O`. |
|
| 41. |
Silicon resembles `B` due toA. Similar values of atomic radiiB. Similar values of `EN`C. Similar values of `IE`D. All of the above |
| Answer» Correct Answer - D | |
| 42. |
Select the correct statements about diborane :A. `B_(2)H_(6)` has three-centre two electron bondB. Each boron atom lies in `sp^(3)` hyrid stateC. `H_(b)….B…H_(b)` bond angle is `122^@`.D. All hydrogens in `B_(2) H_(6)` lie in the same plane. |
|
Answer» Correct Answer - A::B::C In `B_(2) H_(6)`, two boron atoms and four hydrogen atom lie in one plane, whereas the remaining two hydrogen atoms are present prependicular to the plane, i.e. one above the plane and one below the plane. |
|
| 43. |
The molecular shapes of diborane is shown below : . Select correct statement about `B_(2)H_(6)` :A. Bridging groups are electron-deficient with `12` valence electrons.B. It has `(2c, 2e) B-H` bonds.C. It has `(3c, 2e) B-H-B` bonds.D. All of the above are correct statements. |
| Answer» Correct Answer - D | |
| 44. |
The molecular shapes of diborane is shown below : . Consider the following statements for diborane : (i) Boron is approximately `sp^(3)` hybridised. (ii) `B-H-B` angle is `180^@` (iii) There are two terminal `B-H` bonds for each boron atom. (iv) There are only `12` bonding electrons available of These statements :A. (i),(iii) and (iv) are correctB. (i),(ii) and (iii) are correctC. (ii),(iii) and (iv) are correctD. (i),(ii) and (iv) are correct |
| Answer» Correct Answer - A | |
| 45. |
Diborane is prepared on large scale byA. `2BF_(3(g)) + 6LiH_((s)) overset(450 K)rarr B_(2) H_(6(g))+ 6LiF_((s))`B. `2BCI_(3(g))+ 6LiH_((s)) overset(450 K)rarr B_(2)H_(6(g)) + 6LiCl_((s))`C. `2BF_(3(g))+6NaH overset(450 K)rarr B_(2)H_(6) + 6NaF`D. `2BCI_(3) + 6NaH overset(450 K)rarr B_(2)H_(6) + 6NaCI` |
| Answer» Correct Answer - D | |
| 46. |
Which one is covalent compoundA. `Al_(2)(SO_(4))_(3)`B. `Al_(2)O_(3)`C. `AlCl_(3)`D. `AIF_(3)` |
| Answer» Correct Answer - C | |
| 47. |
Which is used in high temperature thermometry ?A. NaB. TiC. GaD. Hg |
| Answer» Correct Answer - C | |
| 48. |
The colour of ferric metaborate isA. YellowB. BlueC. GreenD. Grey |
| Answer» Correct Answer - A | |
| 49. |
The number of isomers possible for disubstituted borazine, `B_(3)N_(3)H_(4)X_(2)` is |
| Answer» Correct Answer - `(4)` | |
| 50. |
Among group `13` elements the one forming an amphoteric oxide isA. TlB. AlC. BD. In |
| Answer» Correct Answer - B | |