52671 + Interview Questions in Chemistry in Class 11

1.	Name an alkali metal carbonate which is thermally ustable and why? Give its decompostion reaction.
Answer» Solution :`Li_(2)CO_(3)` is THERMALLY UNSTABLE because it is covalent. It decomposes to FORM `Li_(2) O` and `CO_(2)` `Li_(2) CO_(3) to Li_(2) O + CO_(2)`

Discussion

2.	Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.
Answer» SOLUTION :A mixture of `CaSO_(4)` and camphor can be separated by the following two methods : (i) Camphor is sublimable but `CaSO_(4)` is not, therefore, sublimation of the mixture gives camphor on the sides of funnel while `CaSO_(4)` is left in the china dish. (ii) Camphor is soluble in organic solvents LIKE `CHCl_(3), C Cl_(4)` etc. while `CaSO_(4)` is not. Therefore, when the mixture is shaken with the solvent, camphor goes into solution while `CaSO_(4)` remains as RESIDUE. It is filtered and evaporation of solvent gives camphor.

Discussion

3.	Name a suitable technique of separation of the components from a mixture of calcium, sulphate and camphor.
Answer» SOLUTION :SUBLIMATION. Because camphor can sublime whereas `CaSO_(4)` does not.

Discussion

4.	Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor
Answer» Solution :Sublimation technique is SUITABLE for separation of the COMPONENTS from a MIXTURE of calcium sulphate and camphor

Discussion

5.	Name a suitable method for separation of components from a mixture of camphor and calcium sulphate.
Answer» Answer :Sublimation method (camphor SUBLIMES, `CaSO_4` does not) or by extracting the MIXTURE with an organic solvent like CHLOROFORM in which only camphor DISSOLVES.

Discussion

6.	Name a substance which could be added to cement without affecting its quality.
Answer» SOLUTION :FLY ASH.

Discussion

7.	Name a substance which acts as halogen carrier during the chlorination of benzene.
Answer» SOLUTION :`FeCl_3`

Discussion

8.	Name a salt that can be added to AgCl so as to produce cation vacancies.
Answer» SOLUTION :`CdCl_(2) or SrCl_(2)`

Discussion

9.	Name a pair of elements which exhibits diagonal relationship.
Answer» SOLUTION :LITHIUM (LI) and MAGNESIUM (MG).

Discussion

10.	Name a mixture used : (i) by all living beings (ii) in te construction for building materials (iii) as a food.
Answer» ANSWER :(i) AIR (ii) Cement (III) MILK

Discussion

11.	Name a member of group 14 element in the periodic table which is used as semi conductor.
Answer» ANSWER :SILICON or SI.

Discussion

12.	Name a functional group whose IUPAC name has only a prefix but no suffix. Give one example.
Answer» SOLUTION :NITRO `(-NO_(2))` GROUP has only a prefix but no suffix.

Discussion

13.	Name a compound whose empirical formula and molecular formula are equal.
Answer» ANSWER :`NH_(3)`

Discussion

14.	Name a compound which does not contain halogen but gives positive Beilestein test.
Answer» ANSWER :UREA

Discussion

15.	Name a chemical which affects diamond.
Answer» SOLUTION :FUSED `Na_2 CO_3`

Discussion

16.	NaI+AgNO_(3)toAgI+NaNO_(2) AgI+Fe to FeI_(2)+Ag FeI_(2)+Cl_(2) to FeCl_(2)+I_(2) (atomic mass of Ag=108, I=127, Fe=56, N=14, Cl=35.5). The above reaction is carried out by taking 75g of NaI and 255 kg of AgNO_(3). Therefore, the number of moles of iodine formed is-
Answer» 0.5 500 250 0.25 Answer :C

Discussion

17.	NaHCO_(3) and NaOH cannot coexist in a solution because of
Answer» common ION effectdue to common `Na^(+)` ions redox reaction occurring between the TWO neutralization reaction occurring between the two different solubilities of the two in water. Solution :`NaHCO_(3)` is acidic salt and canreact with the base NaOH `NaHCO_(3)+NaOH rarr Na_(2)CO_(3)+H_(2)O`

Discussion

18.	NaH produce H_(2) gas when
Answer» It REACTS with water It reacts with heavy water It is electrolysed in FUSED state It is HEATED for decomposition Solution :`NaH+H_(2)OrarrNaOH+H_(2)` `NaHoverset("ELECTROLYSIS" )rarrNa+1/2H_(2)`

Discussion

19.	Na_((g)) +Cl_((g)) to+Cl^(-) ""_((g)) Thisreactionis
Answer» EXOTHERMIC ENDOTHERMIC NEITHER exothermic nor endothermic None of these Answer :B

Discussion

20.	NaCZ (Aq) + Ag NO3 (Aq) rarr AgC+ NaNO,(Aq). The change takes place in the reaction
Answer» LOSS of `e^(-)` gain of `e^(-)` both loss and gain of `e^(-)` REARRANGEMENT of IONS Solution :Clearly in the GIVEN reactionthe rearrange MENT of ions takesplace

Discussion

21.	NaCl_((aq)) +AgNO_(3 (aq)) to AgCl darr +NaNO_(3(aq))thechange taking placehereis
Answer» Loss of `BARE` gain of `bare` Both loss and gain of `bare` Rearrangement of IONS. ANSWER :D

Discussion

22.	NaCl solution is added to a saturated solution of PbCl_(2) . What will happen to the concentration of Pb^(2+) ions ?
Answer» SOLUTION :`Pb^(+)` ion CONCENTRATION will decrease to KEEP `K_(SP)` constant.

Discussion

23.	NaClwhenheatedwith conc: H_(2) SO_(4) andMnO_(2)liberates_______
Answer» HYDROGENGAS CHLORINE GAS Carbondioxidegas hydrogenchloridegas Answer :B

Discussion

24.	NaCl shows Schottky defects and AgCl Frenkel defects. Their electrical conductivity is due to
Answer» MOTION of IONS and not the motion of ELECTRONS motion of electrons and not the motion of ions lower co-ordination NUMBER of NaCl higher co-ordination number of AgCl Answer :A

Discussion

25.	NaCl is not hygroscopic but common table salt is hygroscopic. Why?
Answer» Solution :Table SALT contains CALCIUM chloride and magnesium chloride as IMPURITES which are deliquescent in nature. THUS COMMON table salt is hygroscopic.

Discussion

26.	NaCl gives a golden yellow colour to the Bunsen flame which is due to.
Answer» SUBLIMATION of metallic NA to give yellow vapour Emission of EXCESS ENERGY absorbed as a radiation in the visible region. Low ionization POTENTIAL of Na Photosensitivity of Na Answer :B

Discussion

27.	NaCl crystals require energy ( called lattice energy ) to break into ions. Then why NaCl is soluble in water ?
Answer» Solution :Dissolution of NaCl is a two step PROCESS.The 1st step involvingdissociation of NaCl into ionsrequires, called lattice energy but the 2nd step involves hydration of `NA^(+)` and`Cl^(-)` IONS in which energy is released called hydration energy. THUS, overall process is accompanied by release of energy. Hence NaCl dissolves in WATER.

Discussion

28.	NaCl does not exhibit space isomerism due to
Answer» PRESENCE of ions High MELTING POINT Strong electrostaticforces between the constituentions Non DIRECTIONAL nature of electrovalent bond. Answer :D

Discussion

29.	NaCl crystals have some yellow colour. This is due to the presence of _________
Answer» ANSWER :F-centres

Discussion

30.	NaCl crystal belongs to the crystal system
Answer» hexagonal CUBIC tetragonal orthorhombic Solution :NACL belongs to cubic crystal system.

Discussion

31.	NaCl and CsCl have similar formula. Then why they have different structures ?
Answer» Solution :The radius ratio of NaCl `(r_(Na^+)//r_(Cl^-))` LIES in the RANGE 0.414 -0.732. HENCE , it has a coordination number of 6, i.e., octahedral arrangement . On the other HAND, the radius ratio of CsCl `(r_(CS^+)//r_(Cl^-))` lies in the range 0.732-1.0 . Hence, it has a coordination number of 8, i.e., it has a body-centred cubic arrangement.

Discussion

32.	NaBH_(4) + I_(2) to X + Y + X BF_(3) + NaH overset(450K)(to) X + P BF_(3) + LiAIH_(4) to X + Q + R X,Y,Z,P,Q and R reaction are {:(X,Y,Z,P,Q,R):}
Answer» `{:(Na_(4)B_(4)O_(7),NAI,HI,HF,LiF,AIF_(3)):}` `{:(B_(2)H_(6),NaI,H_(2),NaF,LiF,AIF_(2)):}` `{:(B_(2)H_(6),BH_(3),NaI,B_(3)N_(3)H_(6),AI_(2)F_(6),AIF_(3)):}` `BH_(3),B_(2)H_(6),H_(2),B_(3)N_(3)H_(6),LiF,AIF_(3)` Solution :`2NaBH_(4) + I_(2) to underset((X))(B_(2)H_(6)) + underset((Y))(2NaI) + underset((Z))(H_(2))` `2BF_(3) + 6NaH overset(450 k)(to) underset((X))(B_(2)H_(6)) + underset((F))(6NaF)` `4BF_(3) + 3LiAIH_(4) to underset((x))(2B_(2)H_(6)) + underset((Q))(3LiF) + underset((R ))(3AIF_(3))`

Discussion

33.	NaBH_(4) + I_(2)rarr X uarr + Y uarr + 2Nal X + C_(2)H_(5)OH rarr Y uarr + D X + HCl rarr Y uarr + E D gives following colour with flame
Answer» Red Green Blue No colour Answer :B

Discussion

34.	Na_(2)SO_(4).10H_(2)O(s)hArrNa_(2)SO_(4).5H_(2)O(g) K_(P)=2.43xx10^(-10) atm^(5) incorrect statement is-
Answer» If partial pressure of `H_(2)O` in CONTAINER is `3.5xx10^(-2)` atm amount of `Na_(2)SO_(4).5H_(2)O` decreases. If `P_(H_(2))O=2.5xx10^(-2)` atm then amount of `Na_(2)SO_(4).5H_(2)O` should increases. If `P_(H_(2))O=3xx10^(-2)` atm then both SLID does not get altered. If `Na_(2)SO_(4).5H_(2)O` is COMPLETELY removed then partial pressure of `H_(2)O` increases at equilibrium. Solution :N//A

Discussion

35.	Na_(2)SO_(4) is water soluble but BaSO_(s) is insoluble because
Answer» the hydration energy of `Na_(2)SO_(4)` is higher than that of its lattice energy the hydration energy of `NaSO_(4)` is LESS than that of its lattice energy the hydration energy of `BaSO_(4)` is less than that of its lattice energy the hydration energy of BaSO_(4)` is higher than that of its lattice energy Solution :The solubility of any compound in water depends on both lattice energy & hydration energy. The COMPOUNDS having more hydration energy are only SOLUBLE in water

Discussion

36.	Na_(2)O + CO_(2) to
Answer» Solution :`Na_(2)O + CO_(2) overset("FUSE")(to) Na_(2)CO_(3)`

Discussion

37.	Na_(2)CO_(3).10H_(2)O when exposed to air looses water of crystallisation and gives finally
Answer» `NaCO_(3). 4H_(2)O` `Na_(2)CO_(3). H_(2)O` `Na_(2)CO_(3). 7H_(2)O` `Na_(2)CO_(3). 9H_(2)O` ANSWER :B

Discussion

38.	Na_(2)CO_(3) + Fe_(2)O_(3) rarr A + CO_(2)What is A tn the reaction?
Answer» `NaFeO_(2)` `Na_(3)FeO_(3)` `Fe_(3)O_(4)` `Na_(2)FeO_(2)` SOLUTION :`Na_(2)CO_(3)+Fe_(2)O_(3)rarr2NaFeO_(2)+CO_(2)`

Discussion

39.	Na_(2)B_(4)O_(7).10H_(2)O overset(conc. HCl)rarr A overset(160^(@)C)rarr B. Compound 'B' is
Answer» `H_(2)B_4O_7` `B_(2)O_3` `H_3BO_(3)` `HBO_2` SOLUTION :`Na_(2)B_(4)O_(7).10H_(2)Ooverset(conc.HCl)rarrH_3BO_3overset(100^@C)rarrHBO_2overset(160^2C)rarrunderset("tetraboric ACID")(H_2B_4O_7)`

Discussion

40.	Na_(2)B_(4)O_(7).10H_(2)O can also be represented as
Answer» `Na_(2) [B_(4) O_(5) (OH)_(4)].8H_(2)O` `2NaBO_(2) .Na_(2)B_(2)O_(3).10H_(2)O` `Na_(2)[B_(4)(H_(2)O)_(4).O_(7)].6H_(2)O` All the above Solution :`Na_(2)[B_(4)O_(5)(OH)_(4)].8H_(2)O""` (or) `Na_(2)B_(4)O_(7).10H_(2)O` `B_(2)H_(6)+2NH_(3)overset(120^@C)rarrB_(2)H_(6).2NH_3`

Discussion

41.	Na_(2)B_(4)O_(7)+H_(2)Ooverset("Conc. HCl")underset(Delta)rarrNaCl+X Xoverset(Delta)rarrY. The product Y in the reaction is
Answer» CRYSTALLINE B Amorphous B `B_(2)O_3` `H_(3)BO_(3)` Answer :B

Discussion

42.	Na_(2)CO_(3) can be manufactured by Solva's process but K_(2)CO_(3) cannot be prepared because
Answer» `K_(2) CO_(3)` is moresoluble `K_(2)CO_(3)` is lesssoluble `KHCO_(3)` is moresolublethan`NaHCO_(3) ` `KHCO_(3) ` is lesssoluublethan`NaHCO_(3)` Answer :C

Discussion

43.	Na_2 B_4 O_7.10 H_2 O can also be represented as
Answer» `Na_2 [B_4 O_5 (OH)_4 ]. 8 H_2 O ` `2NaBO_2 .__B_2 O_3 . 10 H_2 O ` `Na_2 [B_4 (H_2 O)_4 . O_7 ] . 6 H_2 O ` All the above Answer :A

Discussion

44.	Na reacts with phenol
Answer» `H_(2)` gas Benzene `CO_(2)` gas CO gas SOLUTION :`C_(6)H_(5)OH+Na rarr C_(6)H_(5)ONa+1//2 H_(2)`.

Discussion

45.	Na shows which type of color flame ?
Answer» Yellow Crimson red Blue Red ANSWER :A

Discussion

46.	Sodium is heated in air at 300^(0)C to form X, X absorbs CO_(2) and forms Na_(2)CO_(3) and Y. Which of the following is Y.
Answer» `H_(2)` `O_(2)` `H_(2)O_(2)` `O_(3)` ANSWER :B

Discussion

47.	Na^+ has higher value of ionization energy than Ne. So ionisation energy of Na^+ is more than Ne.
Answer» ANSWER :EFFECTIVE NUCLEAR CHARGE is more in `NA^+`.

Discussion

48.	Na and Mg crystallise in BCC and FCC type crystals, than the number of Na and Mg atoms present in the unit cell of their respetive crystal is
Answer» 4 and 2 9 and 14 14 and 9 2 and 4 Solution :No. of ATOMS per UNIT cell in BCC structure = 2 No. of atoms per unit cell in FCC structure = 4

Discussion

49.	Na and K have low density, because...
Answer» they have SMALLER size. they have bigger size. due to NUCLEAR attraction force. due to HIGH electronegativity. Answer :B

Discussion

50.	N^(3-),O^(2-),F^-,Na^+, Mg^(2+),Al^(3+) what is comman in them ?
Answer» SOLUTION :They are ISOELECTRONIC (10 ELECTRONS).

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Name an alkali metal carbonate which is thermally ustable and why? Give its decompostion reaction.

Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.

Name a suitable technique of separation of the components from a mixture of calcium, sulphate and camphor.

Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor

Name a suitable method for separation of components from a mixture of camphor and calcium sulphate.

Name a substance which could be added to cement without affecting its quality.

Name a substance which acts as halogen carrier during the chlorination of benzene.

Name a salt that can be added to AgCl so as to produce cation vacancies.

Name a pair of elements which exhibits diagonal relationship.

Name a mixture used : (i) by all living beings (ii) in te construction for building materials (iii) as a food.

Name a member of group 14 element in the periodic table which is used as semi conductor.

Name a functional group whose IUPAC name has only a prefix but no suffix. Give one example.

Name a compound whose empirical formula and molecular formula are equal.

Name a compound which does not contain halogen but gives positive Beilestein test.

Name a chemical which affects diamond.

NaI+AgNO_(3)toAgI+NaNO_(2) AgI+Fe to FeI_(2)+Ag FeI_(2)+Cl_(2) to FeCl_(2)+I_(2) (atomic mass of Ag=108, I=127, Fe=56, N=14, Cl=35.5). The above reaction is carried out by taking 75g of NaI and 255 kg of AgNO_(3). Therefore, the number of moles of iodine formed is-

NaHCO_(3) and NaOH cannot coexist in a solution because of

NaH produce H_(2) gas when

Na_((g)) +Cl_((g)) to+Cl^(-) ""_((g)) Thisreactionis

NaCZ (Aq) + Ag NO3 (Aq) rarr AgC+ NaNO,(Aq). The change takes place in the reaction

NaCl_((aq)) +AgNO_(3 (aq)) to AgCl darr +NaNO_(3(aq))thechange taking placehereis

NaCl solution is added to a saturated solution of PbCl_(2) . What will happen to the concentration of Pb^(2+) ions ?

NaClwhenheatedwith conc: H_(2) SO_(4) andMnO_(2)liberates_______

NaCl shows Schottky defects and AgCl Frenkel defects. Their electrical conductivity is due to

NaCl is not hygroscopic but common table salt is hygroscopic. Why?

NaCl gives a golden yellow colour to the Bunsen flame which is due to.

NaCl crystals require energy ( called lattice energy ) to break into ions. Then why NaCl is soluble in water ?

NaCl does not exhibit space isomerism due to

NaCl crystals have some yellow colour. This is due to the presence of _________

NaCl crystal belongs to the crystal system

NaCl and CsCl have similar formula. Then why they have different structures ?

NaBH_(4) + I_(2) to X + Y + X BF_(3) + NaH overset(450K)(to) X + P BF_(3) + LiAIH_(4) to X + Q + R X,Y,Z,P,Q and R reaction are {:(X,Y,Z,P,Q,R):}

NaBH_(4) + I_(2)rarr X uarr + Y uarr + 2Nal X + C_(2)H_(5)OH rarr Y uarr + D X + HCl rarr Y uarr + E D gives following colour with flame

Na_(2)SO_(4).10H_(2)O(s)hArrNa_(2)SO_(4).5H_(2)O(g) K_(P)=2.43xx10^(-10) atm^(5) incorrect statement is-

Na_(2)SO_(4) is water soluble but BaSO_(s) is insoluble because

Na_(2)O + CO_(2) to

Na_(2)CO_(3).10H_(2)O when exposed to air looses water of crystallisation and gives finally

Na_(2)CO_(3) + Fe_(2)O_(3) rarr A + CO_(2)What is A tn the reaction?

Na_(2)B_(4)O_(7).10H_(2)O overset(conc. HCl)rarr A overset(160^(@)C)rarr B. Compound 'B' is

Na_(2)B_(4)O_(7).10H_(2)O can also be represented as

Na_(2)B_(4)O_(7)+H_(2)Ooverset("Conc. HCl")underset(Delta)rarrNaCl+X Xoverset(Delta)rarrY. The product Y in the reaction is

Na_(2)CO_(3) can be manufactured by Solva's process but K_(2)CO_(3) cannot be prepared because

Na_2 B_4 O_7.10 H_2 O can also be represented as

Na reacts with phenol

Na shows which type of color flame ?

Sodium is heated in air at 300^(0)C to form X, X absorbs CO_(2) and forms Na_(2)CO_(3) and Y. Which of the following is Y.

Na^+ has higher value of ionization energy than Ne. So ionisation energy of Na^+ is more than Ne.

Na and Mg crystallise in BCC and FCC type crystals, than the number of Na and Mg atoms present in the unit cell of their respetive crystal is

Na and K have low density, because...

N^(3-),O^(2-),F^-,Na^+, Mg^(2+),Al^(3+) what is comman in them ?