94420 + Interview Questions in Chemistry in Class 12

1.	Cis-2butene and transjj-2-buteneare:
Answer» GEOMETRICAL ISOMERS diasteroeomers enantiomers position isomers. Answer :A::C::D

Discussion

2.	Cis-2-butene and trans-2-butene can be distinguished on the basis of
Answer» their optical properties <BR>their reduction products the products they give on ozonolysis the products they give on ADDITION of bromine. Solution :Options (a), (b) and (c) are wrong since cis-2- butene and trans-2-butene are not OPTICALLY active, give same product on hydrogenation, ie., n-butane and same product on ozonolysis, ie.,` CH_(3) `CHO. But addition of `Br_(2)` to these two isomers gives DIFFERENT products. Whereas cis-2-butene gives d-mixture of 2,3-dibromobutane, trans-2-butene gives meso-2,3 dibromobutane.

Discussion

3.	Cis-2-butene and trans-2-butene are:
Answer» configurational ISOMERS Structural isomers CONFORMATIONAL isomers. optical isomers. ANSWER :A

Discussion

4.	Cis-1,4-polyisoprene ' is
Answer» Thermoplastic Thermosetting PLASTIC Elastic (rubber) RESIN Solution :Natural rubber is the only ADDITION polymer of NATURE and is known as Cis-1,4-polyisoprene.

Discussion

5.	Cis-1,4- polysoprene is called
Answer» Buna-N NEOPRENE Buna-S NATURAL rubber. Answer :D

Discussion

6.	Cinnamic acid towards electrophilic aromatic substitution
Answer» metal directing o-p directing Ipso substitution TAKES place Equally give ORTHO, PARA and META SUBSTITUTED product Answer :B

Discussion

7.	Cinnamic acid on decarboxylation gives
Answer» Benzaldehyde Toluene Styrene Benzene Answer :C

Discussion

8.	Cinnamic acid is formed when C_(6)H_(5)-CHO condenses with (CH_(3)CO)_(2)O is presence of
Answer» Conc. `H_(2)SO_(4)` Sodium acetate Sodium metal Anhydrous `ZnCI_(2)` Solution :`C_(6)H_(5)CHO+(CH_(3)CO)_(2)O overset(CH_(3)CO_(2)Na)rarr C_(6)H_(5)CH=CHCO_(2)H`

Discussion

9.	Cinnamic acid is formed when C_6H_5CHO condenses with (CH_3CO_2)_2Oin the presence of .................
Answer» CONC. `H_2SO_4` `CH_3COONa` NA metal Anhydrous `ZnCl_2` SOLUTION :`CH_3COONa`

Discussion

10.	Cinnamic acid is ortho-para directing. Explain
Answer» Solution :It is easier to explain this ORIENTATION by CONSIDERATION of the stabilities of the various carbonium ions. For p-attack For m-attack ` (##FIITJEE_CHE_MB_08_C03_SLV_005_S01.png" width="80%"> Only in case of o and p-attack spreading of positive charge to the side chain is possible , thereby STABILIZING these more than m-attack.

Discussion

11.	Cinnamaldehyde on reduction with NaBH_4 gives
Answer» `C_(6)H_(5)CH_(2)CH_(2)CH_(2)OH` `C_(6)H_(5)CH=CH-CH_(3)` `C_(6)H_(5)CH=CH-CHO` `C_(6)H_(5)CH=CHCH_(2)OH` Solution :`NaBH_(4)` does not reduce C=C double BOND.

Discussion

12.	Cinnabar is an ore of :
Answer» LEAD ZINC SILVER MERCURY ANSWER :D

Discussion

13.	Cinnabar is :
Answer» `Cu_2S` `Ag_2S` `ZNS` `HGS` ANSWER :D

Discussion

14.	Cinnabar (HgS) and galena (PbS) on roasting often give their respective metals but zinc blende (ZnS) does not . Explain .
Answer» Solution :On roasting all these sulphide ores are partly converted into their RESPECTIVE OXIDES . Since the oxides of mercury and lead are unstable while that of zinc is stable , therefore , oxides of mercury and lead bring about the reduction of their respective sulphides to the CORRESPONDING metals but zinc oxide does not reduce ZnS to Zn metal `HgS + underset("(unstable)")(2 HgO) overset(Delta)(to) 3 HG+ SO_(2) ,` `PbS + underset("(unstable)")(2PbO) overset(Delta)(to) 3 Pb + SO_(2)` `ZnS + underset("(stable)") (2ZnO) to 3 Zn + SO_(2)`

Discussion

15.	CI^(Θ)is condirned by (a) ____.
Answer» ANSWER :a.Chrumyl CHLORIDE TEST

Discussion

16.	Cimetidine (Tegamet) and Ranitidine (Zantac) drugs are
Answer» Analgesics Tramquilizers Antacids Antidepressants Answer :C

Discussion

17.	Cigarette or gas lighter is made up of
Answer» Misch METAL Alkali metal Noble metal None Solution :Misch metal MAINLY CONTAINS Lanthenoids and IRON.

Discussion

18.	CIF_3 exists but FCl_3 does not exist. Why?
Answer» Solution :Chlorine can accommodate three small sized F atoms around it but small sized Fatom cannot accommodate three big sized Cl atoms around it. MOREOVER, FLUORINE cannot EXHIBIT valency more than one due to the absence of vacantd-orbitals

Discussion

19.	CIF_(3) and BrF_(3) are used in the enrichment of _______.
Answer» `""^(237)NP` `""^(235)U` `""^(152)Eu` `""^(210)Po` Answer :B

Discussion

20.	Consider the standard potential of the following cells, (i)Mg^(2+) +2e rarr Mg,E^@=-2.37V (ii)Zn^(2+) + 2erarrZn,E^@ =-0.76V (iii)Ni^(2+) +2e rarrNi,E^@=-0.25V(iv)Fe^(3+) + 3e rarrFe, E_0=-0.04 Vfind the strongest reducing agent :
Answer» `MG^(2+)` Mg `FE^(3+)` Fe Answer :B

Discussion

21.	Chromyl ion is :
Answer» `CrO_(2)^(+)` `CrO_(2)^(2+)` `CRO^(2+)` `CrO_(2)^(3+)` ANSWER :B

Discussion

22.	Chromyl chloride vapours are dissolved in water and acetic acid and lead acetate solution is added, then
Answer» The solution will remain colourless the solution will become dark GREEN A yellow solution will be OBTAINED A yellow ppt. will be obtained Solution :`CrO_(2)Cl_(2)+2H_(2)O to H_(2)CrO_(4)+2HCl` `H_(2)CrO_(4)+(CH_(3)CO O)_(2)Pb` `to underset("Yellow ppt.")(PbCrO_(4) darr) +2CH_(3)CO OH`

Discussion

23.	Chromyl chloride vapours are dissolved in water and acetic acid and barium acetate solution is added then:
Answer» the solution will remain colourless the solution will become dark green a yellow solution will be obtained a yellow precipitate will be obtained Solution :`CrO_(2)Cl_(2)+2H_(2)OtoH_(2)CrO_(4)+2HCl` `H_(2)CrO_(4) +(CH_(3)COO)_(2)BA to BaCrO_(4)DARR ("yellow")+2CH_(3)COOH`

Discussion

24.	Chromyl chloride testis preformedfor thedetectionof CI^(Theta) A saltsolutioncontaining CI^(Theta) ionis heated with K_(2)Cr_(2)O_(7) and cone H_(2)SO_(4) orange redvapour of Cr_(2)CI_(2)are obatined .Onpassingthese supourthrough a soln of NaOH a yellowppt ,dueto Na_(2)CrO_(2) is obtained if these vapour are dissolve in H_(2)O and acetin acid and leadacetate solutionis added then
Answer» The SOLUTION will remaincolour less The solution will BECOME dark green The solution will become BROWN A yellow PPT will be obtained Answer :d

Discussion

25.	Chromyl chloride test is performed for the confirmation of the presence of the following in a mixture
Answer» Sulphate Chromium CHLORIDE Chromium and chloride Solution :It is a TEST for chloride ION.

Discussion

26.	Chromyl chloride test is given by -
Answer» `CH_(3)CL` `AgCl` `Hg_(2)Cl_(2)` `NH_(4)Cl` ANSWER :D

Discussion

27.	Chromyl chloride test is for
Answer» CHLORIDE salt nitrate salt thiosulphate salt sulphate salt Answer :A::C::D

Discussion

28.	Chromyl chloride in CS_(2)(CrO_(2)Cl_(2)//CS_(2)) or chromium trioxide in acetic anhydride [CrO_(3)//(CH_(3)CO)_(2)O] followed by acid hydrolysis.
Answer» SOLUTION :(i) Reactivity increases as the +ve charge on CARBONYL carbon increases. Since alkyl GROUPS have +I-effect, therefore, reactivity increases as the number of alkyl groups on the carbonyl carbon decreases. (ii) Reactivity increases as the number and size of alkyl groups decreases, i.e., STERIC hindrance decreases. due to combined effect of these two factors, the reactivity increases in the order. `C_(2)H_(5)COCH_(3) lt CH_(3)COCH_(3) lt CH_(3)CHO lt HCHO`.

Discussion

29.	Chromium trioxide in acidic medium acts as oxidising agent. What is this reagent known as ?
Answer» SOLUTION :JONES REAGENT

Discussion

30.	Chromosomes are made of ............................
Answer» Only NUCLEIC ACIDS Only PROTEINS Proteins and nucleic acid Proteins and CARBOHYDRATES SOLUTION :Proteins and nucleic acids

Discussion

31.	Chromium plating can involve the electrolysis of an electroyte of an acidified mixture of chromic acid and chromium sulphate. If during electrolysis the article being plated increases in mass by 2.6 g and 0.6" dm"^(3) of oxygen are evolved at an inert anode, the oxidation state of chromium ions being discharged must be (assuming Cr = 58 and 1 mole of gas at room temperature and pressure occupies of 24" dm"^(3))
Answer» A) `+2` B) 0 C) `+1` D) `-1` ANSWER :A

Discussion

32.	Chromium plating can involve the electrolysis of an electrolyte of an acidified mixuture of chromic acid and chromium sulphate . If during electrolysis the article being plated increases in mass by 2.6 g and 0.6 dm3 of oxygen are evolved at an inert anode, the oxidation state of chromium ions being discharged must be:(assuming Cr=52) and I mole of gas at room temperature and pressure occupies a volume of 24 dm^3)
Answer» `-1` ZERO `+1` `+2` ANSWER :D

Discussion

33.	Chromium metal crystallizes with a body-centred cubic lattice. The length of the unit cell edge is found to be 287pm. Calculate the atomic radius. What woulds be the density of chromiumin g cm^(-3)?
Answer» SOLUTION :124.27 PM, `7.32 g//cm^3`

Discussion

34.	Chromium metal crystallizes with a body-centred cubic lattice. The edge length of the unit cell is found to be 287pm. Calculate the atomic radius. What would be the density of chromium in g cm^(-3) ? (atomic mass of Cr = 52.99)
Answer» SOLUTION :For a body - centred cubic lattic , Z= 2 Edge length , a= 287 pm = `287 xx 10^(-10) cm` ATOMIC mass of CHROMIUM , M = 52.99 g `"mol"^(-1)` For bcc lattice , R = `(sqrt3)/(4) xx a` `=(1.732)/(4) xx a` `=(1.732)/(4)xx 287 ` pm = 124.27 pm `d= (Z xx M)/(a^3 xx N_A)` `=(2xx 52.99 g "mol"^(-1))/((287 xx 10^(-10) cm)^3 xx 6.02 xx 10^(23) "mol"^(-1))` =7.44 g `"cm"^(-3)`

Discussion

35.	Chromium metal crystallizes in a body centred cubic lattice. The length of the unit cell edge is found to be 287 pm. Calculate the atomic radius of chromium.
Answer» SOLUTION :a=287 PM For a body-centred cubic UNIT cell, RADIUS (r) = `(a xx sqrt3)/(4)= (287 xx sqrt3)/(4) =(287 xx 1.73)/(4)` = 124.13 pm

Discussion

36.	Chromium metal can be plated out from an acidic solution containing CrO_3according to the following equationCrO3_(aq) + 6H^(+)(aq) + 6etoCr(s) + 3H_2OCalculate (i) how many grams of chromium will be plated out by 24000 coulombs, and (ii) how long will it take to plate out 1.5 g of chromium by using 12.5 amp current?
Answer» Solution : Eq. of CR DEPOSITED = FARADAY of ELECTRICITY passed ` = 24000/96500` and eq. wt. of chromium ` = 52/6` 2.1554g, 1336 g

Discussion

37.	Chromium is used in making:
Answer» Bronze Brass Stainless steel Electrodes Answer :C

Discussion

38.	Chromium is typical hard metal while mercury is a liquid. Explain why ?
Answer» SOLUTION :Cr has five unpaired d-ELECTRONS. Hence METALLIC bonds are STRONG. In Hg, there is absence of unpaired electrons and SIZE is larger.

Discussion

39.	Chromium is obtained by reducing purified chromite ore with....
Answer» red hot COKE carbon MONOXIDE AL powder `H_(2(g))` Answer :C

Discussion

40.	Chromium is a typical hard metal while mercury is a liquid. Explain why ?
Answer» SOLUTION :Cr has five unpaired d electrons in the d-subshell `( 3d^(5) 4S^(1))` . HENCE, metallic BONDS are very strong. In Hg, all the d-orbitals are fully filled `( 3d^(10) 4s^(2))`. Hence, the metallic bonding is very weak.

Discussion

41.	Chromium has most stable oxidation state of:
Answer» `+5` `+3` `+2` `+4` ANSWER :B

Discussion

42.	Chromium dissolves in dil. H_2SO_4 to form Cr(H_2O)_6^(2+). The colour of the ion is:
Answer» Blue Green Yellow Orange Answer :A

Discussion

43.	Chromium crystallizes in a body centred cubic lattice, whose density is 7.20 g//cm^3. The length of the edge of unit cell is 288.4 pm. Calculate Avogadro's number. (Atomic mass of chromium=52)
Answer» SOLUTION :d= 7.20 g `cm^(-3)`, a=288.4 PM, Z2 for bcc unit cell, M = 52 g `MOL^(-1)`, d = `(Z XX M)/(N_A xx a^3)` or `N_A=(Z xx M)/(d xx a^3)=(2xx52)/(7.20 xx (288.4)^3 xx 10^(-30)) =6.02 xx 10^(23) mol^(-1)`

Discussion

44.	Chromium compound used in training of leather is:
Answer» `Cr_2O_3` `CrO_2Cl_2` `CrCl_3` `K_2SO_4cdotCr(SO_4)_3cdot24H_2O` ANSWER :D

Discussion

45.	Chromium carbonyl is:
Answer» `Cr(CO)_4` `Cr(CO)_5` `Cr(CO)_6` None Answer :C

Discussion

46.	Chromite ore is fused with Na_(2)CO_(3) in free excess of air. The yellow solution obtained is filtered and acidified with H_(2)SO_(4). The colour of the resulting solution is
Answer» COLOURLESS. pink. orange. green. Answer :C

Discussion

47.	Chromite ore has the formula "…....................".
Answer» ANSWER :`FEO. Cr_(2)O_(3)`

Discussion

48.	Chromite is ...........
Answer» SOLUTION :`FeCr_2O_4`

Discussion

49.	The chemical formula of chromite mineral :
Answer» SOLUTION :`FeCr_3O_4`

Discussion

50.	Chromite has the formula
Answer» SOLUTION :`FeCr_3O_4`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Cis-2butene and transjj-2-buteneare:

Cis-2-butene and trans-2-butene can be distinguished on the basis of

Cis-2-butene and trans-2-butene are:

Cis-1,4-polyisoprene ' is

Cis-1,4- polysoprene is called

Cinnamic acid towards electrophilic aromatic substitution

Cinnamic acid on decarboxylation gives

Cinnamic acid is formed when C_(6)H_(5)-CHO condenses with (CH_(3)CO)_(2)O is presence of

Cinnamic acid is formed when C_6H_5CHO condenses with (CH_3CO_2)_2Oin the presence of .................

Cinnamic acid is ortho-para directing. Explain

Cinnamaldehyde on reduction with NaBH_4 gives

Cinnabar is an ore of :

Cinnabar is :

Cinnabar (HgS) and galena (PbS) on roasting often give their respective metals but zinc blende (ZnS) does not . Explain .

CI^(Θ)is condirned by (a) ____.

Cimetidine (Tegamet) and Ranitidine (Zantac) drugs are

Cigarette or gas lighter is made up of

CIF_3 exists but FCl_3 does not exist. Why?

CIF_(3) and BrF_(3) are used in the enrichment of _______.

Consider the standard potential of the following cells, (i)Mg^(2+) +2e rarr Mg,E^@=-2.37V (ii)Zn^(2+) + 2erarrZn,E^@ =-0.76V (iii)Ni^(2+) +2e rarrNi,E^@=-0.25V(iv)Fe^(3+) + 3e rarrFe, E_0=-0.04 Vfind the strongest reducing agent :

Chromyl ion is :

Chromyl chloride vapours are dissolved in water and acetic acid and lead acetate solution is added, then

Chromyl chloride vapours are dissolved in water and acetic acid and barium acetate solution is added then:

Chromyl chloride test is performed for the confirmation of the presence of the following in a mixture

Chromyl chloride test is given by -

Chromyl chloride test is for

Chromyl chloride in CS_(2)(CrO_(2)Cl_(2)//CS_(2)) or chromium trioxide in acetic anhydride [CrO_(3)//(CH_(3)CO)_(2)O] followed by acid hydrolysis.

Chromium trioxide in acidic medium acts as oxidising agent. What is this reagent known as ?

Chromosomes are made of ............................

Chromium metal crystallizes with a body-centred cubic lattice. The length of the unit cell edge is found to be 287pm. Calculate the atomic radius. What woulds be the density of chromiumin g cm^(-3)?

Chromium metal crystallizes with a body-centred cubic lattice. The edge length of the unit cell is found to be 287pm. Calculate the atomic radius. What would be the density of chromium in g cm^(-3) ? (atomic mass of Cr = 52.99)

Chromium metal crystallizes in a body centred cubic lattice. The length of the unit cell edge is found to be 287 pm. Calculate the atomic radius of chromium.

Chromium is used in making:

Chromium is typical hard metal while mercury is a liquid. Explain why ?

Chromium is obtained by reducing purified chromite ore with....

Chromium is a typical hard metal while mercury is a liquid. Explain why ?

Chromium has most stable oxidation state of:

Chromium dissolves in dil. H_2SO_4 to form Cr(H_2O)_6^(2+). The colour of the ion is:

Chromium crystallizes in a body centred cubic lattice, whose density is 7.20 g//cm^3. The length of the edge of unit cell is 288.4 pm. Calculate Avogadro's number. (Atomic mass of chromium=52)

Chromium compound used in training of leather is:

Chromium carbonyl is:

Chromite ore is fused with Na_(2)CO_(3) in free excess of air. The yellow solution obtained is filtered and acidified with H_(2)SO_(4). The colour of the resulting solution is

Chromite ore has the formula "…....................".

Chromite is ...........

The chemical formula of chromite mineral :

Chromite has the formula