Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

Element commonly used in modern semiconductor devices isA. SiB. CC. SnD. Pb

Answer» Correct Answer - A
Silicon (Si) is commonly used in modern semiconductor devices like diodes, transistors, I.C. etc.
Discussion
2.

Block tin is not purified byA. LiquationB. PolingC. Electro refiningD. Fractional distillation

Answer» Correct Answer - D
Fractional distillation is not used to purify block tin.
Discussion
3.

The chief ore of tin isA. GalenaB. CerrusiteC. Tin stoneD. Anglesite

Answer» Correct Answer - C
Tinstone is `SnO_(2)`.
Discussion
4.

Which of the following statements is correct ?A. Both `SnCl_(4)` and `SnBr_(4)` are colouredB. All `SnCl_(4),SnBr_(4)` and `SnI_(4)` are colouredC. only `SnBr_(4)` is colouredD. Only`SnI_(4)` is coloured.

Answer» Correct Answer - D
Only `SnI_(4)` has bright organge colour. The colour is due to the absorption of blue light, hence the reflected light contains hight proportion of red and orange.
Discussion
5.

Which one of the following reacts with conc. `H_(2)SO_(4)` ?A. AuB. AgC. PtD. Pb

Answer» Correct Answer - B
Concentrated `H_(2)SO_(4)` reacts with Ag on heating to given `SO_(2)`
`2Ag+2H_(2)SO_(4) to Ag_(2)SO_(4) +2H_(2)O+SO_(2)`
The attack of conc.` H_(2)SO_(4)` on Pb is prevented due to the formation of insoluble `PbSO_(4)` layer. Conc. `H_(2)SO_(4)` does not attack Au or Pt.
Discussion
6.

Freon-12 is used as aA. RefrigerantB. InsecticideC. FungicideD. Herbicide

Answer» Correct Answer - A
Freon-12 (a chlorofluorohydrocabon or CFC) is a refrigerant.
Discussion
7.

In laboratory, silicon can be prepared by the reaction ofA. SiO2 with MgB. By heating C in electric furnaceC. By heating potassium fluorosilicate with potassiumD. None of these

Answer» Correct Answer - A
In laboratory Si can be prepared by heating `SiO_(2)` with Mg
`SiO_(2) +2Mg to Si+2MgO`
Discussion
8.

`SiH_(4)+NaOH +H_(2)O to X +3H_(2)` X in the above reaction isA. `H_(2)SiO_(3)`B. `SiH_(3)Ona`C. `Na_(2)SiO_(3)`D. `SiO_(2)`

Answer» Correct Answer - C
Monosilane `SiH_(4)` is soluble in strong alkalis in presence of air. However it differs from `CH_(4)` in its action with NaOH.
`SiH_(4)+NaOH+H_(2)O to Na_(2)SiO_(3)+3H_(2)`
Discussion
9.

When steam is passed through red hot coke:A. `CO+H_(2)`B. `CO_(2)+H_(2)`C. `H_(2)+O_(2)`+StreamD. none of these

Answer» Correct Answer - A
`underset("Red hot")(C)+underset("Stream")(H_(2)O) to ubrace(CO+H_(2))_("Water gas")`
Discussion
10.

Which of the following elements reacts with silicon at room temperatureA. OxygenB. ChlorineC. FluourineD. Nitrogen

Answer» Correct Answer - C
`Si+2F_(2) to SiF_(4)`
Discussion
11.

In the manufacture of cement which of the following is used ?A. Clay and silicaB. Lime stone and silicaC. Lime stone and clayD. Lime stone and gypsum

Answer» Correct Answer - B
Cement is manufactured from lime stone and clay.
Discussion
12.

The geometry of `SiO_(4)^(4-)` ion isA. TetrahedralB. Square PlanarC. OcthosilicatesD. Planar triangular

Answer» Correct Answer - A
It has tetrahedral geometry.
Discussion
13.

`Na^(+), Mg^(2+), Al^(3+)`, and `Si^(4+)` are isoelectronic ions. Their ionic size will follow the orderA. `Na^(+) gt Mg^(2+) gt Al^(3+) lt Si^(+4)`B. `Na^(+) gt Mg^(2+) lt Al^(3+) gt Si^(+4)`C. `Na^(+) gt Mg^(2+) gt Al^(3+) Gt Si^(+4)`D. `Na^(+) gt Mg^(2+) gt Al^(3+) lt Si^(+4)`

Answer» Correct Answer - C
In isoelectronic cations, the size decreases with increases in nucler charge
`Na^(+) gt Mg^(2+) gt Al^(3+) gt Si^(4+)`
Discussion
14.

Silicon hydrides are calledA. SilaneB. Silicon hydrogen compoudC. Hydrogen silicidesD. silicones

Answer» Correct Answer - A
Silicon hydrides are called silanes and have general formula `Si_(n)H_(2n+2)`
Discussion
15.

Which is not correct ?A. Lead is poor conductor of electricityB. `PbCl_(4)` forms stable double salt with `NH_(4)Cl`C. Lead is malleable and ductileD. `SnCl_(2)` is a solid.

Answer» Correct Answer - C
Lead is malleable but not ductile.
Discussion
16.

The non existence of `PbI_(4)//PbBr_(4)` is due toA. small size of `Pb^(4+)` and larger size of `Br^(-)//I^(-)` ionsB. highly oxidising nature of `Pb^(4+)` ionsC. highly reducing nature of `I^(-)//Br^(-)` ionsD. Both (B) and (C)

Answer» Correct Answer - D
`Pb^(4+)` ion because of its high oxidising nature gets immediately reduced to `Pb^(2+)` by strong reductant `I^(-)//Br^(-)` hence `PbI_(4)` and `PbBr_(4)` are not possible.
Discussion
17.

Which of the following true acid anhydride?A. `Al_(2)O_(3)`B. COC. `CO_(2)`D. CaO

Answer» Correct Answer - C
`H_(2)CO_(3)overset(-H_(2)O)toCO_(2)`
Discussion
18.

Which of the following does not exhibit allotropy ?A. TinB. CarbonC. PlumbumD. Silicon

Answer» Correct Answer - C
Plumbum (Pb) does not show allotropy , all the other three show this property.,
Discussion
19.

Which oxidation state is not shown by carbon in its compounds?A. `-4`B. 4C. 1D. 0

Answer» Correct Answer - C
In `CH_(4)` oxidation state of C is -4. In `CF_(4)` oxidation state of C is +4.
Discussion
20.

In which of the following compounds carbon shows an oxidation state of -2 ?A. `CH_(3)OH`B. `CH_(2)Cl_(2)`C. `C_(12)H_(22)O_(11)`D. CO

Answer» Correct Answer - A
In `CH_(3)OH` the O.N. of C is -2.
Discussion
21.

Which of the following elements exhibit maximum number of allotropes ?A. CarbonB. siliconC. TinD. Lead

Answer» Correct Answer - C
Tin shows maximum no. of 3 allotropes.
`alpha -"Tin" overset(284 K)to beta -"Tin" overset(442K)to gamma-"Tin"`
Discussion
22.

A compound in which the oxidation number of carbon is zero isA. `CO_(2)`B. `C_(2)H_(6)O`C. `C_(6)H_(12)O_(6)`D. none the above

Answer» Correct Answer - C
`overset("(x)")(C)_(6)overset(+1)(H)_(12)overset(-2)(O)_(6)`
6`x` + 1 x 12-2 x 6=0
`6x`+12-12=0 or `6x`=0 or `x=0`
Discussion
23.

The electronegativity of the following elements increases in the orderA. C,N,Si,PB. N ,Si , C ,PC. Si , P , C , ND. P , Si ,N ,C

Answer» Correct Answer - C
correct order of electronegativity
Si ltPltCltN
(Out of these four elements, N is most electronegative)
Discussion
24.

Which of the following elements occur in free state 3 ?A. SiB. GeC. SnD. C

Answer» Correct Answer - D
Coal deposits are found commonly.
Discussion
25.

Ge (II) compounds are powerful reducing agents whereas Pb(IV) compound are strong oxidants. It can be due toA. Pb is more electropositive than GeB. ionization potential of lead is lesst than that of GeC. ionic radii of `Pb^(2+)` and `Pb^(4+)` are larger than those of `Ge^(2+)` and `Ge^(4+)`D. more pronounced inert pair effect in lead than in Ge.

Answer» Correct Answer - D
Ge(IV) is more stable than Ge(II). Therefore, Ge(II) compounds are powerful reducing agent. Pb(IV) is less stable than PB(II). Therefore, Pb(IV) compounds are powerful oxidising agents. This is due to inert pair effect, due to which the +2 oxidation state becomes more stable as we move down the group.
Discussion
26.

Amongst the elements of group 14 the oxidising power of the tetravelent species increases in the orderA. GeltPbltSnB. GeltSnltPbC. PbltGeltSnD. None of the above

Answer» Correct Answer - B
Ge lt Sn lt Pb
Oxidation involves decreases in oxidation state of the oxidising agent. Since `Pb^(2+)` is stabler than `Pb^(4+)` while `Ge^(4+)` is stabler than `Ge^(2+)` due to inert pair effect, the oxidising power of the tetravelent species increases in the order Ge lt Sn lt Pb
Discussion
27.

Which of the following bonds has the most polar character ?A. C - OB. C -C. C -SD. C -F

Answer» Correct Answer - D
As F is most electronegative, C-F bondwill be most polar.
Discussion
28.

The sequence of acidic character isA. `SO_(2) gt CO_(2) gt CO gt N_(2)O_(5)`B. `SO_(2) gt N_(2)O_(5) gt CO gt CO_(2)`C. `N_(2)O_(5) gt SO_(2) gt CO gt CO_(2)`D. `N_(2)O_(5) gt SO_(2) gt CO_(2) gt CO`

Answer» Correct Answer - D
Correct order of acidic character is `N_(2)O_(5) gt SO_(2) gt CO_(2) gt CO` Please not that CO is a neutral oxide.
Discussion
29.

Which oxide is weakly basic and at the same time a powerful oxidising agent ?A. `SiO_(2)`B. `PbO_(2)`C. `CO_(2)`D. `SnO_(2)`

Answer» Correct Answer - B
`PbO_(2)` is oxidant as well as base.
Discussion
30.

Lead (IV) oxide is obtained byA. heating lead (II) oxide strongly in airB. heating lead strongly in pure oxygenC. oxidising lead with conc. `HNO_(3)`D. none of these

Answer» Correct Answer - D
`Pb_(3)O_(4)+4HNO_(3) overset(Delta)to2Pb(NO_(3))_(2)+2H_(2)O+PbO_(2)`
Discussion
31.

Stannous oxide can be obtained byA. heating tin strongly in airB. heating meta-stannic acidC. heating tin (II) oxalateD. none of these

Answer» Correct Answer - C
`underset("Tin (II) oxalate")(SnC_(2)O_(4)) overset(Delta)toSnO+CO uarr+CO_(2)uarr`
Discussion
32.

Which of the following structure is similar to graphite e?A. `B_(2)H_(6)`B. BNC. BD. `B_(4)C`

Answer» Correct Answer - B
BN has a structural similar to graphite. It consists of sheets made up of hexagonal rings of alternate B and N atoms joined together.
Discussion
33.

Butter of tin is:A. `SnCl_(2).5H_(2)O`B. `SnCl_(2).2H_(2)O`C. `SnCl_(2).4H_(2)O`D. `SnCl_(4).5H_(2)O`

Answer» Correct Answer - D
Butter of tin is `SnCl_(4).5H_(2)O`
Discussion
34.

When formic acid or oxalic acid is treated with conc. `H_(2)SO_(4)` , the gas evolved isA. `H_(2)S`B. COC. `SO_(2)`D. `CO_(2)`

Answer» Correct Answer - B
`{:(CO OH),("|"),(CO OH):} overset(Conc. H_(2)SO_(4))toCO+CO_(2)+H_(2)O`
`HCO OH overset(Conc. H_(2)SO_(4))toCO +H_(2)`
Conc. `H_(2)SO_(4)` acts as a dehydrating agent eliminates water.
Discussion
35.

When oxalic acid is dehydrated by conc. `H_(2)SO_(4)` then it formsA. `C+CO_(2)`B. COC. `CO_(2)`D. `CO+CO_(2)`

Answer» Correct Answer - D
`{:(CO OH),("|"),(underset("Oxalic acid")(CO OH)):} overset(Conc. H_(2)SO_(4))toH_(2)O+CO +CO_(2)`
Discussion
36.

White lead isA. `Na_(2)CO_(3)`B. `Pb_(3)O_(4)`C. `Pb(OH)_(2).2PbCO_(3)`D. `PbO`

Answer» Correct Answer - C
White lead is `Pb(OH)_(2).2PbCO_(3)` (basic lead carbonate).
Discussion
37.

Which of the following on thermal decomposition yields a basic as well as an acidic oxide?A. `NaNO_(3)`B. `KClO_(3)`C. `CaCO_(3)`D. `NH_(4)NO_(3)`

Answer» Correct Answer - C
(A) `2NaNO_(3) overset(Delta)to2NaNO_(2)+O_(2)`
(B) `2KClO_(3) overset(Delta)to2KCl+3O_(2)`
`(C) CaCO_(3) overset(Delta)to underset("Basic")(CaO)+underset("Acidic")(CO_(2))`
(D) `NH_(4)NO_(3) overset(Delta)toN_(2)O+2H_(2)O`
Discussion