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.	Silicon dioxide is formed by the reaction of
Answer» `SiCl_(4)+2H_(2)O` `SiO_(2)` `SiO_(2)+NaOH` `SiCl_(4)+NaOH` ANSWER :A

2.	Silicon crystallizes in a unit cell to that of diamond. Find the unit-cell content for Si.[Hint: Diamond has a face-centred cubic unit cell containing a tetrahedron of atoms.]
Answer» ANSWER :8

3.	Silicon dioxide is an example of:
Answer» METALLIC CRYSTAL Ionic crystal Covalent crystal None Answer :C

4.	Silicon crystallises in fcc lattice, a single crystal of high purity like diamond. Gram atomic weight of silicon is 28 g mol^(-1). Edge length of unit cell is 0.543nm. Calculate the number of silicon atoms per unit cell and density of unit cell.
Answer» SOLUTION :8,2.33 G C `c^(-1)`

5.	Silicon carbide is very hard. Justify this statement.
Answer» Solution :Silicon CARBIDE is very hard, It is a covalent SOLID contains the atoms which are bound together in a THREE dimensional network entirely by covalent bonds. So the covalent network crystal sic is very hard and have high melting POINT.

6.	Silicon carbide is used as:
Answer» DEHYDRATING agent Abrasive Solvent Catalyst Answer :B

7.	Silicon chloroform is prepared by
Answer» Si + HCl `SiCl_(4) + H_(2)O` `SiF_4 + NAF` `H_(2)SiF_(6) + Cl_(2)` SOLUTION :`Si+ 3HClto UNDERSET("Silicon CHLOROFORM")(SiHCl_(3) + H_(2))`

8.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Determine the pH of 0.1 M aqueous solution of copper sulphate at 25^(@)C assuming that its hydrolysis occurs in small degree only. Use the value of the first acidity constant of [Cu(H_(2)O)_(4)]^(2+) K_(a)=1xx10^(-7) M.
Answer» ANSWER :A

9.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Write down equation of a reaction between aqueous of CuSO_(4) and sodium metasilicate (LGL). Take into account the pH values of aqueous solutions of the salts.
Answer» ANSWER :A

10.	Silicon carbide is an example of
Answer» Ionic solid Covalent solid Polar MOLECULAR solid NON - polar molecular solid Solution :Covalent solid

11.	Silicon carbide (Carborandum) (armor stone) is which type of solid ?
Answer» Metallic solid IONIC solid MOLECULAR solid COVALENT solid ANSWER :D

12.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Using the same strategy as in 3.3 to 3.5 depict a fragment of the layered structure joining 16 tetrahedra (i). Note that 10 tetrahedra have shared vertices with 2 neighbours each, and the rest 6 have shared vertices with 3 neighbours each. Being placed into the LGL solution, salts of transition metals give rise to fancy "trees" tinted relevant to the colour of the salt of the the corrsponding transition metal. Crystals of CuSO_(4).5H_(2)O produce "trees" of blue colour whereas those of NiSO_(4).7H_(2)O form green "trees".
Answer» ANSWER :A

13.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Depict its structure joining together several tetrahedra (i). Take into account that any adjacent terahedron shares one vertex. Charged monolayers with the composition [Si_(4)O_(10)]^(m-) are found in daolinite (clay).
Answer» ANSWER :A

14.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Determine the number of oxygen atoms bridging adjacent tetrahedra.
Answer» ANSWER :A

15.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Determine the charge (n).
Answer» ANSWER :A

16.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. The solution of LGL was used earlier as office glue. Write down the net ionic equation accounting for the ability of LGL to set in air. Hydrolysis of LGL in water allows abtaining a colloidal solution of silicic acid.
Answer» ANSWER :A

17.	Silicates as the base of the Earth crust Silica and compounds derived from it, silicates, constituteca. 90% of the Earth crust substances. Silica gives rise to a beautiful meterial-glass. Nobody knows exactly how glass was discovered. There is a well-favoured story related to phoenician sailors who fused occassionally sea sand and soda ash. It is likely that they discovered the secret of "liquid glass" (LGL) sodium metasilicate (Na_(2)SiO_(3)) soluble in water. Write down the net ionic equations matching the prosesses enumerated. For each prosess mark Yes if if leads to changes of pH. Otherwise mark NO. (a) Protonation of ortho-silicate ions leading to the formation of Si-OH groups. (b) Formation of hydrated [SiO_(4)(H_(2)O)_(2)]^(4-) anions (c) Polycondensation of ortho-silicate ions leading to the formation of Si-O-Si bonds. The structure of species occurring in aqueous solutions of silicates in rather complex. However, it is possible to distinguish the main building block of all species-orthosilicate tetrahedron (SiO_(4)^(4-))
Answer» ANSWER :A

18.	Silicate contains silicon and oxygen in ………………… units.
Answer» `[SiO_(4)]^(4-)` `[SiO_(4)]` `[SiO_(4)]^(2-)` `[SiO_(4)]^(-)` ANSWER :A

19.	Silica is used as
Answer» an ACIDIC flux a BASIC flux a REDUCING agent an OXIDISING agent Answer :A::C::D

20.	Silica is added to roasted copper ore during smelting in order to remove_________.
Answer» CUPROUS sulphide cuprous oxide ferrous oxide ferrous sulphide Answer :C

21.	Silica is added to roasted copper ore during smelting in order to remove :
Answer» CUPROUS OXIDE cuprous SULPHIDE FERROUS sulphide ferrous oxide. ANSWER :A

22.	Silica is added to roasted copper ore during smelting process to remove-
Answer» ferrour sulphide ferrous oxide CUPROUS sulphide cuprous oxide ANSWER :B

23.	Silica gel is utilised for the_______ of the number of gases.
Answer» adsorption absorption desorption all of these Answer :A

24.	Silica gel is usually adsorb.........
Answer» Colourants Hydrogen Liquid Helium WATER SOLUTION :Water

25.	Silica gel is used for keeping away the moisture because it :
Answer» ABSORBS`H_2O` ADSORBS`H_2O` REACTS with `H_2O` None Answer :B

26.	Silica gel is used for keeping away the moisture because it
Answer» REACTS with `H_(2)O` Adsorbs `H_(2)O` Absorbs `H_(2)O` None Answer :C

27.	Silica dissolves readily in
Answer» HF HCl HI `HNO_3` ANSWER :A

28.	Silca gel placed in water vapour results in ………… whereas calcium chloride placed in water vapour results in ………….
Answer» SOLUTION :ADSORPTION, ABOSORPTION

29.	Significant figures in 0.00051 are:
Answer» 5 3 2 4 Answer :C

30.	sigma-complex formed in the chlorination of benzene is
Answer» All of these Answer :D

31.	Sigma bond between CI and O in CIO_4^(-) is formed by ---- overlapping
Answer» <P>`SP^(2)-p` `sp^(2)-s` `sp^(3)-s` `sp^(3)-p` ANSWER :D

32.	Sidgwick EAN rule says that complexcompoundhas the tendency to achieve the EAN of 36, 54 and 86 for first, second and third transition series elements. Which of the following complex acts as reducing agent based on Sidgwick EAN rule ?
Answer» `Mn(CO)_(5)` `Mn_(2)(CO)_(10)` `Mn(CO)_(6)` `[V(CO)_(6)]^(-)` Solution :`UNDERSET(EAN=37)(Mn(CO)_(6)) to underset(EAN=36)(Mn(CO)_(6)^(+)+e^(-))`

33.	Sidgwick EAN rule says that complexcompoundhas the tendency to achieve the EAN of 36, 54 and 86 for first, second and third transition series elements. Which of the following complex follows sidgwick EAN rule ?
Answer» `[Ag(S_(2)O_(3))_(2)]^(3-)` (when only S atom is the DONOR atom) `[Cd(CN)_(4)]^(2-)` `[Pt(en)_(2)]^(2+)` `[Mo(sigma-C_(3)H_(5))Br(NH_(3))_(2)]^(0)` Solution :(a)`[Ag(S_(2)O_(3))_(2)]^(3-) implies 47-1+4=50` (b) 48-2+8=54 (C ) 78-2+8=84 (d) 42-2+8=48

34.	Sidgwick EAN rule says that complexcompoundhas the tendency to achieve the EAN of 36, 54 and 86 for first, second and third transition series elements. Which of following statement is not correct regarding complex "Ferrocene".
Answer» EAN of central ATOM in ferrocene is not equal to its nearest noble gas Molecule is having aromtic CHARACTER It has sandwich LIKE STRUCTURE Two rings act as `pi-"donor ligand"` Solution :`[overset(+2)(Fe)(eta^(5)-C_(5)H_(5))_(2)],"EAN"=26-2+12=36`

35.	SiF_(4) gets hydrolysed giving ....
Answer» `SiO_(2)` `Si(OH)_(2)F_(2)` `H_(2)SiF_(6)` `Si(OH)_(4)` SOLUTION :It is hydrolysed with water to form a `Si(OH)_(4)`.

36.	Sides of match box have coating of
Answer» POTASSIUM chlorate, RED LEAD Potassium chlorate , ANTIMONY sulphide Antimony sulphide, red phosphorus Antimony sulphide, red lead Answer :C

37.	Siderite mineral is
Answer» SULPHATE of iron CARBONATE of ZINC Sulphate of zinc Carbonate of iron Answer :D

38.	Siderite is
Answer» `Fe_(2)O_(3)` `FeCO_(3)` `SnO_(2)` `ZnC` SOLUTION :Siderite is `FeCO_(3)`, an ore of IRON (a) `Fe_(2)O_(3)` is haematite, (b) `SnO_(2)` is TIN stone or CASSITERITE (d) ZnO is called zincite.

39.	Side chain oxidation of toluene in the presence of KMnO_4gives ..........
Answer» SOLUTION :BENZOIC ACID

40.	Side chain chlorination of methyl benzenefollowed by hydrolysis gives
Answer» PHENOL ANILINE ANISOLE BEZALDEHYDE ANSWER :D

41.	Side product during the preparation of dacron fibre is
Answer» glycerol ETHYLENE GLYCOL ethyl alcohol PROPYLENE glycol Answer :B

42.	SiCl_(4) on hydrolysis forms 'X' and HCl, compound 'X' losses water at 1000^(@)C and gives 'Y'. Compounds 'X' and 'Y' are respectively
Answer» `H_(2)SiCl_(6),SiO_(2)` `H_(4)SiO_(4),Si` `SiO_(2),Si` `H_(4)SiO_(4),SiO_(2)` Answer :D

43.	Si(CH_(3))_(2)Cl_(2) is hydrolysed. What type of polymer is formed ?
Answer» SOLUTION :Hydrolysis of `Si(CH_(3)) _(2)Cl_(2)` is given as `Si(CH_(3))_(2)Cl_(2)overset(H_(2)O,OH^(-))rarrSi(CH_(3))_(2)(OH)_(2)` The hydrolysis product UNDERGOES condensation HOMOPOLYMERISATION. The product is an example of inorganic POLYMER, called polysiloxane. `nHO-overset(CH_(3))overset("\|")underset(CH_(3))underset("\|")"Si"-OH+HO-overset(CH_(3))overset("\|")underset(CH_(3))underset("\|")"Si"-OH underset(-nH_(2)O)rarr HO[--overset(CH_(3))overset("\|")underset(CH_(3))underset("\|")"Si"-O--]-overset(CH_(3))overset("\|")underset(CH_(3))underset("\|")"Si"-OH`

44.	(Si_(2)O_(5))_(n)^(2n-) anion is obtained when :
Answer» no OXYGEN of a `SiO_(4)^(4-)` tetrahedron is shared with another `SiO_(4)^(4-)`tetrahedron one oxygen of a `SiO_(4)^(4-)`tetrahedron is shared with another `SiO_(4)^(4-)` tetrahedron two oxygen of a `SiO_(4)^(4-)` tetrahedron are shared with another `SiO_(4)^(4-)` tetrahedron three oxygen of a `SiO_(4)^(4-)` tetrahedron are shared with another `SiO_(4)^(4-)` tetrahedron Answer :D

45.	SI unit of energy is:
Answer» `KG m^(2)s^(-2)` `kg m^(-1)s^(2)` `kg m^(2)s^(-1)` `kg m^(2)s^(2)` ANSWER :A

46.	S.I. Unit of caloric value is given by_____.
Answer» ANSWER :kJ/gm

47.	Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the ftems in polythene bags and gave them to Shyam. But Shyam refused to accpt the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags. Answer the following What is a biodegradable polymer? Give an example
Answer» SOLUTION :Which can be degraded by MICROORGANISMS, EG PHBV (or any other correct EXAMPLE)

48.	Si and Ge used for semiconductors are required to be of high purity and hence purified by :
Answer» zone–refining electrorefining Van–Arkel’s process cupellation process Answer :A

49.	Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the ftems in polythene bags and gave them to Shyam. But Shyam refused to accpt the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags. Answer the following Why did Shyam refuse to accept the items in polythene bags?
Answer» SOLUTION :As it is non-biodegradable

50.	Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the ftems in polythene bags and gave them to Shyam. But Shyam refused to accpt the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags. Answer the following Write one one structural difference between low-density polythene and high-density polythene.
Answer» SOLUTION :LOW density polythene is highly branched while HIGH density polythene is linear