94420 + Interview Questions in Chemistry in Class 12

1.	Mercury is purified by:
Answer» passing through DILUTE `HNO_(3)` distillation distribution vapour phase refining Answer :B

Discussion

2.	Mercury is purified by :
Answer» Solidifying DISTILLATION in vaccum TREATMENT with dil.`HNO_3` Electrolytic method Answer :B

Discussion

3.	Mercury is in liquid form because…
Answer» as d-orbital is COMPLETELY FILLED up so d-d OVERLAPPING is not possible as d-orbital is completely filled up so d-d overlapping is possible its s-orbital is COMPLETEY filled up its VOLUME is very small Answer :A

Discussion

4.	Mercury is emitted into air by :
Answer» BURNING coal Burning garbage Coal fire Steam engine Answer :B

Discussion

5.	Mercury is a liquid metal because
Answer» It has a completely FILLED d- orbital that prevents d-d overlapping of ORBITALS It has a completely filled d- orbital that causes d-d overlappping It has a completelyfilled s- orbital It has a small ATOMIC size Solution :Mercury is a SILVERY white heavy liquid (sp. Gravity 13.6). It has a completely filled d orbital that prevents d-d overlapping of orbitals.

Discussion

6.	Mercury is a liquid at 0^(@)C because of:
Answer» very HIGH ionisation energy weak METALLIC bonds high heat of hydration high heat of sublimation Answer :A::B

Discussion

7.	Mercury is a liquid at 0^@C because of
Answer» Very high ionisation ENERGY WEAK METALLIC bonds high HEAT of hydration high heat of sublimation Solution :Weak intermolucular forces of atractions

Discussion

8.	Mercury (II) chloride solution on reaction with gaseous ammonia forms:
Answer» `Hg(NH_(3))Cl*HgO` `Hg(NH_(3))_(2)Cl_(2)` `[Hg(NH_(3))_(2)]Cl_(2)` `[Hg(NH_(3))_(2)]Cl` Answer :A

Discussion

9.	Mercury forms amalgams with all except :
Answer» Al Zn Ni Fe Answer :D

Discussion

10.	Mercuric iodate [Hg_(5)(IO_(6))_(2)] reacts witha mixture of KI and HCI according to the following equation . Hg_(5)(IO_(6))_(2) +34 KI +24 HCl to 5K_(2)HgI_(4) +8I_(2) +24KCl +12H_(2)O The liberated odine is treated with na_(2)S_(2)O_(3) solution , 1 mL of which isequivalentto 0.0499g of CuSO_(4).5H_(2)O.What volume( in mL ) of Na_(2)S_(2)O_(3) solutionwill be required to react with iodine liberated from 0.7245 g of [Hg_(5) (IO_(6))_(2)] ? [Hg = 200.5 , Cu = 63.5 ,I = 127 ]
Answer» Solution :From the stoichmetry of the given EQUATIONS , `Hg_(5) (IO_(6))_(2) +34 KI+24 HCI to 5K_(2)HgI_(4) +8I_(2) +24KCI +12H_(2)O` and `2Cuso_(4) .5H_(2)O + 4KI to Cu_(2)I_(2) + 2K_(2)SO_(4) +I_(2)` we have , ` 8 xx " moles of " Hg_(5)(IO_(6))_(2) = " moles of " I_(2)` and moles of `CuSO_(4) .5H_(2)O = 2 xx" moles of " I_(2)` ` :. " moles of " I_(1) = 1/2 xx " moles of " CuSO_(4) .5H_(2)O ` ` = 8 xx " moles of " Hg_(5) (IO_(6))_(2)` or moles of `CuSO_(4) .5H_(2)O = 16 xx` moles of `Hg (IO_(6))_(2)` `("wt . of " CuSO_(4).5H_(2)O)/(249.5) = 16 xx (0.7245)/(1448.5){{:(CuSO_(4).5H_(2)O=249.5),(Hg_(5)(IO_(6))_(2)=1448.5):}}` ` :. ` wt of `CuSO_(4) .5H_(2)O = 1.9967 G ` Since `0.0499` g of `CuSO_(4) . 5H_(2) = 1 ` mL of `Na_(2)S_(2)O_(3)` ` :.1.9967 " g of " CuSO_(4) . 5H_(2)O = (1.9967)/(0.0499) = 40` mL

Discussion

11.	Mercurous ion can be represented as
Answer» `HG^(+)` `Hg^(+)-Hg^(+)` `Hg_(2)^(2+)` `Hg^(2+)` SOLUTION :`Hg_(2)^(2+) -= Hg^(+1) - Hg^(+1)`

Discussion

12.	Mercuric chloride reacts withphosphine give
Answer» `Hg_(3)P_(2)` `HgP_(2)` `Hg_(3)P` `HgP` Answer :A

Discussion

13.	Mercuric chloride is reduced to mercurous chloride by:
Answer» ACETIC acid CARBON tetrachloride Formic acid Ammonia ANSWER :C

Discussion

14.	Mercuric chloirdieisreducedtomercurouschloride by .
Answer» acethicacid `C Cl_(4)` `HCO OH` `NH_(3)` ANSWER :C

Discussion

15.	Mercuric chloride is converted into mercury by:
Answer» placing copper METAL in aqueous solution of `HgCl_(2)` treating aqueous solution of `HgCl_(2)` with excess of stannous chloride treating aqueous solution `HgCl_(2)` with `PbCl_(2)` solution NONE of these Answer :A::B

Discussion

16.	Mention which of the following are addition polymers? (i) terylene (ii) nylon-6,6 (iii) neoprene (iv) teflon.
Answer» SOLUTION : NEOPRENE and TEFLON.

Discussion

17.	Mention two uses of sulphuric acid.
Answer» SOLUTION :(i) In the manufacture of fertilizers. (ii) In the manufacture of paints, pigments DYES, drugs and explosives. (iii) In the refining of petroleium (iv) In the electric batteries (v) As drying and dehydrating agent (VI) In the manufacture of detergents, `HCl, HNO_(3), H_(3)PO_(4)` etc. (vii) In the manufacture of alum (VIII) As LABORATORY reagent

Discussion

18.	Mention two reactions of benzene to show its behaviours isdifferent from that of the open chain unsaturatedhydrocarbons.
Answer» Solution :Benzene does not decolourise bromine-water. 2 Benzene does NTO REACT with halogen acids such as HCl,HBR etc.

Discussion

19.	Mention two important uses of sulphanilic acid.
Answer» Solution :Sulphanilic ACID is USED in the manufacture of (i) DYES (ii) sulpha drugs.

Discussion

20.	Mention two important uses of each of the following : Nylon-6
Answer» SOLUTION :Nylon-6 : For making tyre cords, FABRICS, ROPES ETC.

Discussion

21.	Mention two important uses of sulfanilic acid.
Answer» SOLUTION :It is used : (i) in the MANUFACTURE of DYES. (ii) in the manufacture of sulfa DRUGS.

Discussion

22.	Mention two important uses of each of the following: (i) Bakelite (ii) Nylon 6
Answer» Solution :USEOF `{:(,"(i)BAKELITE " ," (ii)NYLON 6"),(,"(a) for makingcombs","(a) for makingtyre CORD"),(,"(b) for making electrical switches ","(b) formakingfabrics and ROPE"):}`

Discussion

23.	Mention two important uses of each of the following : Bakelite
Answer» Solution :Bakelite : For making COMBS, electrical switches, HANDLES of UTENSILS,computer DISC ETC.

Discussion

24.	Mention twoimportantsubstances present in the 'anodemud' obtainedin theelectrorefiningofcopper.
Answer» SOLUTION :TWO importantsubstancespresentin theanode mudaresilverandgold.

Discussion

25.	Mention two important functions of carbohydrates in plants.
Answer» Solution :Major energy SOURCE, storage MOLECULES like STRACH in plants.

Discussion

26.	Mention two important features of solid catalysts and explain then with the help of suitable example .
Answer» Solution :Heterogeneous CATALYST, activity and selectivity of catalysts. Example, HYDROGENATION of UNSATURATED HYDROCARBONS in presence of Raney Ni or any other example.

Discussion

27.	Mention two example of emulsifying agents for o/w emulsions and w/o emulsions.
Answer» SOLUTION :For o/w EMULSIONS : PROTEINS , GUMS, SOAPS,

Discussion

28.	Give two difference between starch and cellulose.
Answer» SOLUTION :`{:("Starch",,"Cellulose"),((i)" MADEUP of " prop - "D GLUCOSEUNITS.",,"Madeup of" beta "-D glucoseunits."),((II)"Haslinearandbranchedpolymeric chains",,"It is alinearpolymer."):}`

Discussion

29.	Mention two classes of nitrogen containing bases found in nucleotides.
Answer» SOLUTION :PURINES and PYRIMIDINES.

Discussion

30.	Mention to which oxyacids N_(2)O, N_(2)O_(4) and N_(2)O_(5) are anhydrides?
Answer» SOLUTION :`N_(2)O_(3)` is anhydride of NITROUS acid and `N_(2)O` is anhydride of nitric acid. `N_(2)O_(4)` is a mixed anhydride of nitrous acid and nitric acid. `N_(2)O_(3) +H_(2)O to 2HNO_(2), N_(2)O_(5)+H_(2)O to 2HNO_(3)` `N_(2)O_(4)+H_(2)O to HNO_(2) +HNO_(3)`

Discussion

31.	Mention threee areas in which H_2SO_4 plays an important role.
Answer» SOLUTION :Three areas in which `H_2SO_4` has important applications are given below : (i) It is used as an electrolyte in STORAGE batteries. (ii) It is used in PETROLEUM REFINING, detergent industry and in the manufacture of paints, pigments and dyes. (iii) `H_2SO_4`is used in the manufacture of fertilisers such as AMMONIUM sulphate, calcium superphosphate.

Discussion

32.	Mention three characteristics of ideal solutions. What cause deviation from ideal behaviour ? Discuss the positive deviations from ideal behaviour.
Answer» Solution :Characteristics of an ideal solution (1) It must obey Raoult.s law (2) `Delta `H (MIX) = 0 (3)`Delta `V (mix) = 0 Cause of positive deviations from Raoult.s law. Consider a binary solution having components A and B. If the A B interactions in the solution are weaker than the A-A and B-B interactions in the two liquids forming the solution, then the escaping tendency of A and B types of molecules from the solution becomes more than pure liquids. As a result each component of the solution has a partial vapour pressure greater than expected on the basis of Raoult.s law. The total vapour pressure will be greater than the corresponding vapour pressure expected in case of ideal solution of the same composition. This type of behaviour of solution is described as positive deviations from Raoult.s law. This may be expressed as `P_A gt P_(A)^(@)x_A` or ` P_Bgt P_(B)^(@) x_(B)` The positive deviations have been shown in Fig. In the figure, dotted lines show the ideal behaviour. Explanation for positive deviations. Let us consider a solution of ethanol and cyclohexane. In ethanol, the molecules are held together due to hydrogen bonding as shown below. On adding cyclohexane, the cyclohexane molecules come in between the molecules of ethanol, and break the hydrogen bonds. As the RESULTING solution has weaker intermolecular attractions decreases, THEREFORE the escaping tendency of alcohol and cyclohexane molecules from the solution increases. Hence the vapour pressure of the solution is greater than the vapour pressure as expected from Raoult.s law

Discussion

33.	Mention three areas in which H_2SO_4 plays an important role.
Answer» Solution :(i) In manufacture of fertilizers, (ii) In manufacture of PIGMENTS, paints and DRY STUFFS, (iii) In detergent industry.

Discussion

34.	Mention three areas in which H_(2)SO_(4) plays an important role.
Answer» Solution :(i) `H_(2)SO_(4)` is used in the manufacture of fertilizers such as AMMONIUM sulphate, CALCIUM super phosphate. (ii) It is used as an ELECTROLYTE in stroge BATTERIES. (iii) It is used in petroleum refining, detergent INDUSTRY and in the manufacture of paints, pigments and dyes.

Discussion

35.	Mention the uses the carbon monoxide.
Answer» SOLUTION :(i) Equimolar mixture of hydrogen and carbon monoxide -water gas and the mixture of carbon monoxide and NITROGEN producer gas are important industrial fuels. (II) Carbon monoxide is a good reducing agent and can reduced many METAL oxides to metals. (iii) Carbon monoxide is an important ligand and forms carbonyl compound with transition metals.

Discussion

36.	Mention three anomalouos behaviour of oxygen.
Answer» Solution :(i) Oxygen is diatomic gas while other ELEMENTS of this GROUP are solids. (ii) Oxygen FORMS hydrogen bonds while other elements do not. (iii) Oxygen has a maximum covalency of FOUR while other elements can SHOW a maximum of six.

Discussion

37.	Mention the uses of the potash alum.
Answer» Solution :(i) It is used for purification of water. (ii) It is also used for water PROOFING and TEXTILES (III) It is used in dyeing, PAPER and LEATHER tannineg industries (iv) It is employed as a styptic agent to arrest bleeding.

Discussion

38.	Mention the uses of sulphurdioxide?
Answer» SOLUTION :(i) Sulphur dioxide is used in BLEACHING hair, silk, wool etc………… (II) It can be used for DISINFECTING crops and plants in agriculture.

Discussion

39.	What are the uses of silicon tetra chloride ?
Answer» Solution :(i) SILICON tetrachloride is used in the PRODUCTION of semiconducting silicon. (II) It is used as a starting meterial in the synthesis of silica gel, SILICIC ester, a BINDER forceramic materials.

Discussion

40.	Mention the uses of PCl_(3) and PCl_(5)?
Answer» SOLUTION :(i) Phosphorus trichloride is used as a chlorinating AGENT and for the PREPARATION of `H_(3)PO_(3)`. (ii) Phosphorous pentachloride is a chlorinating agent and is USEFUL for replacing hydroxyl groups by chlorine atom.

Discussion

41.	Mention the uses of phosphorus?
Answer» Solution :(i) The RED phosphorus is used in the match BOXES. (ii) It is also used for the PRODUCTION of certain alloys such as phosphor BRONZE.

Discussion

42.	Mention the uses of oxygen.
Answer» Solution :1. Oxygen is one of the essential COMPONENT for the survival of living organisms. 2. It is used in welding (oxyacetylene welding) 3. LIQUID oxygen is used as FUEL in rockets etc.

Discussion

43.	Mention the uses of nitrogen?
Answer» Solution :(i) Notrogen is used for the manufacture of AMMONIA, nitric acid and CALCIUM CYANAMIDE etc. (ii) LIQUID nitrogen is used for producing low TEMPERATURE required in cryosugery, and so in biological preservation

Discussion

44.	Mention the uses of Neon?
Answer» Solution :Neon is used in advertisement as neon sign and the BRILLIANT RED glos is caused by passing electric CURRENT through neon gas under LOW pressure.

Discussion

45.	Mention the uses of methanol.
Answer» Solution :(i) Methanol is uscd as a solvent for PAINTS, VARNISHES, SHELLAC, gums, CEMENT, ete. (ii) Methanol is used in the manufacture of dyes, DRUGS, perfumes and formaldehyde.

Discussion

46.	Mention the uses of hydrochloric acid ?
Answer» Solution :(i) Hydrochloric acid is used for the manufacture of chlorine, ammonium chloride, GLUCOSE from corn starch etc., (II) It is used in the extractionof glue from BONE and also for purification of bone black.

Discussion

47.	Mention the uses of Gold (Au).
Answer» Solution :Uses of Gold (Au): 1. Gold, one of the expensive and precious METALS. It is used for coinage, and has been used as standard for monetary SYSTEMS in some countries. 2. It is used extensively in jewellery in its alloy form with copper. It is also used in electroplating to cover other metals with a thin LAYER of gold which are used in watches, artifical limb JOINTS, cheap jewellery, DENTAL fillings and electrical connectors. 3. Gold nanoparticles are also used for increasing the efficiency of solar cells and also used an catalysts.

Discussion

48.	Mention the uses of Glycerol.
Answer» Solution :1. Glycerol is used as a sweetening agent in confectionery and BEVERAGES. 2. It is used in the MANUFACTURE of COSMETICS and transparent soaps. 3. It is used in making printing inks and stamp pad ink and lubricant for watches and clocks. 4. It is used in the manufacture of explosive like dynamite and cordite by mixing it with china clay.

Discussion

49.	Mention the uses of formic acid?
Answer» Solution :FORMIC acid. It is used (i) for the dehydration of hides. (ii) as a coagulating agent for rubber latex (III) in medicine for TREATMENT of gout (iv) as an antiseptic in the PRESERVATION of fruit juice

Discussion

50.	Mention the uses of formaldehyde.
Answer» Solution : (i) 40% aqueous solution of formaldehyde is called formalin. It is used for preserving biological specimens. (II) Formalin has hardening effect, hence it is used for tanning. (iii)Formalin is used in the PRODUCTION of thermo setting plastic known as bakelite, which is OBTAINED by HEATING PHENOL with formalin.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Mercury is purified by:

Mercury is purified by :

Mercury is in liquid form because…

Mercury is emitted into air by :

Mercury is a liquid metal because

Mercury is a liquid at 0^(@)C because of:

Mercury is a liquid at 0^@C because of

Mercury (II) chloride solution on reaction with gaseous ammonia forms:

Mercury forms amalgams with all except :

Mercurous ion can be represented as

Mercuric chloride reacts withphosphine give

Mercuric chloride is reduced to mercurous chloride by:

Mercuric chloirdieisreducedtomercurouschloride by .

Mercuric chloride is converted into mercury by:

Mention which of the following are addition polymers? (i) terylene (ii) nylon-6,6 (iii) neoprene (iv) teflon.

Mention two uses of sulphuric acid.

Mention two reactions of benzene to show its behaviours isdifferent from that of the open chain unsaturatedhydrocarbons.

Mention two important uses of sulphanilic acid.

Mention two important uses of each of the following : Nylon-6

Mention two important uses of sulfanilic acid.

Mention two important uses of each of the following: (i) Bakelite (ii) Nylon 6

Mention two important uses of each of the following : Bakelite

Mention twoimportantsubstances present in the 'anodemud' obtainedin theelectrorefiningofcopper.

Mention two important functions of carbohydrates in plants.

Mention two important features of solid catalysts and explain then with the help of suitable example .

Mention two example of emulsifying agents for o/w emulsions and w/o emulsions.

Give two difference between starch and cellulose.

Mention two classes of nitrogen containing bases found in nucleotides.

Mention to which oxyacids N_(2)O, N_(2)O_(4) and N_(2)O_(5) are anhydrides?

Mention threee areas in which H_2SO_4 plays an important role.

Mention three characteristics of ideal solutions. What cause deviation from ideal behaviour ? Discuss the positive deviations from ideal behaviour.

Mention three areas in which H_2SO_4 plays an important role.

Mention three areas in which H_(2)SO_(4) plays an important role.

Mention the uses the carbon monoxide.

Mention three anomalouos behaviour of oxygen.

Mention the uses of the potash alum.

Mention the uses of sulphurdioxide?

What are the uses of silicon tetra chloride ?

Mention the uses of PCl_(3) and PCl_(5)?

Mention the uses of phosphorus?

Mention the uses of oxygen.

Mention the uses of nitrogen?

Mention the uses of Neon?

Mention the uses of methanol.

Mention the uses of hydrochloric acid ?

Mention the uses of Gold (Au).

Mention the uses of Glycerol.

Mention the uses of formic acid?

Mention the uses of formaldehyde.