94420 + Interview Questions in Chemistry in Class 12

1.	Iodine oxidises S_(2)O_(3)^(2-) ion to 'X', change in oxidation state of sulphur
Answer» `+3` `+2` `+0.5` `+4` ANSWER :C

Discussion

2.	IUPAC name of acetic acid is :
Answer» Methanal 2- Pentanone Ethanoic acid Methanoic acid. Answer :D

Discussion

3.	Iodine oxidises S_2O_3^(2-)ion to:
Answer» `SO_3^(2-)` `SO_4^(2-)` `S_4O_6^(2-)` `S^(2-)` ANSWER :C

Discussion

4.	Iodine molecules are held in the crystals lattice by
Answer» LONDON forces dipole-dipole interactions covalent bonds coulombic forces Solution :IODINE is a MOLECULAR solid and MOLECULES in it are held by London forces.

Discussion

5.	IUPAC name for the amine CH_(3)-underset(CH_(3))underset(\|)(N)-underset(C_(2)H_(5))underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3) is ………
Answer» 3-Bimetylamineo-3-methyl pentane 3(N,N-Triethyl)-3-AMINO pentane 3-N,N-trimethyl pentanamine 3-(N,N-Dimethyl amino)-3-methylpentane Answer :D

Discussion

6.	Iodine molecules are held in the crystals lattice by ……
Answer» London FORCES dipole-dipole interactions covalent BONDS coulombic forces Solution :`I_2` is non-polar MOLECULAR SOLID.

Discussion

7.	Iodine may be liberated from sodium iodate by:
Answer» `H_2SO_4` `NaHSO_3` `KMnO_4` HCl Answer :B

Discussion

8.	IUPAC name of 1^(0) amine is
Answer» ALKYL AMINE dialkanamine ALKANAMINE trialkanamine ANSWER :C

Discussion

9.	Iodine is violet coloured. Why?
Answer» Solution :IODINE is a bigger molecule , in which the valence electrons are not HELD very strong by the nuclei in the molecule .It absorbs low energy orange -RED radiation of visible LIGHT and reflects its complimentary colour . Hence iodine is VIOLET coloured .

Discussion

10.	Iodine is soluble in water in the presence of :
Answer» `KI`<BR>`Cl_(2)` `Br_(2)` `KBr`. Solution :Because of the FORMATION of `KI_(3)`.

Discussion

11.	IUPAC name m-toluic acid is
Answer» 3-methylbenzoic ACID 2-methylbenzoic acid 4-methylbenzoic acid 2,4 - dimethylbenzoic acid ANSWER :A

Discussion

12.	Iodine is ______type solid.
Answer» SOLUTION :IODINE is a MOLECULAR TYPE SOLID

Discussion

13.	IUPACnamefor theamine CH_(3)- underset(CH_(3))underset(\|)N - underset(C_(2)H_(5))underset(\|) overset(Ch_(3))overset(\|)C-CH_(2)-CH_(5) is
Answer» 3- Bimethylamino -3- METHYL pentane 3(N, N - Triethyl) -3- AMINO pentane 3- N, N - TRIMETHYL pentanamine 3- ( N, N - DIMETHYL amino ) -3- methyl pentane Answer :D

Discussion

14.	Iodine is released when potassium iodine reacts with
Answer» `ZnSO_(4)` `CuSO_(4)` `FeSO_(4)` `(NH_(4))_(2)SO_(4)` Answer :B

Discussion

15.	Iodine is placed between two liquids C_6H_6 and water:
Answer» It DISSOLVES more in `C_6H_6` It dissolves more in water It dissolves EQUALLY in both Does not DISSOLVE in both Answer :A

Discussion

16.	IUPAC name for the amine {:(""CH_(3)),("\|"),(CH_(3)-N-C-CH_(2)-CH_(3)),("\|\|"),(""CH_(3)CH_(2)H_(5)):} is
Answer» 3-Dimethylamino-3-methyl pentane 3(N, N-Triethyl)-3-aminopentane 3-N, N-Trimethyl pentanamine 3-N, N-Dimethylamino-3-methylpentane. Solution :`{:(""CH_(3)),("\|"),(H_(3)C-Noverset(3)(-C)-OVERSET(2)(C)H_(2)-overset(1)(C)H_(3)),("\|""4\|"),(""CH_(3)""CH_(2)-overset(5)(C)H_(3)),("3-N, N-Dimethylamino-3-methylpentane"):}`

Discussion

17.	Iodine is more soluble in KI than in water. Why ?
Answer» SOLUTION :Iodine combines with KI to FORM the SOLUBLE complex, `KI_(3) (KI +I_(2) rarr KI_(3))`.

Discussion

18.	IUPAC name ethyl menthyl amineis
Answer» ETHYL METHANAMINE N-methyl ETHANAMINE diethyanamine dimethanamine ANSWER :B

Discussion

19.	Iodine is more soluble in alcohol than in carbon tetrachloride because
Answer» iodine and alcohol both are non-polar randomness factor is greater in alcohol than in `C Cl_(4)` dissolution of iodine in alcohol is EXOTHERMIC whereas it is endothermic dissolution of both is endothermic but heat of dissolutionin alcohol is less than in `C CI_(4)` SOLUTION :in edothermic PROCESS of dissolution, ENERGY factor opposes the dissolution.Less is the heat of dissolution, i.e.,less is the opposing factor,greater is the solubility.

Discussion

20.	IUPAC name crotonaldehyde is _____.
Answer» SOLUTION :2 BUTENAL

Discussion

21.	Iodine is libereated when Cu^(2+)reacts with KI but chlorine isnot liberatedwhen Cu^(2+)is allowed to react with KCI. Why ?
Answer» SOLUTION :`I^(-)` IONS is a strongerreducingagentthan `CI^(-)`ION `(2Cu^(2+)+4KI to Cu_(2)I_(2) + I_(2) + 4K^(+))`,

Discussion

22.	IUPAC has recommended the use of the lerm conductivity over specific conductivity.
Answer» ANSWER :TRUE

Discussion

23.	I.underset((cold and dlll))(2NaOH)+Cl_(2)rarr...A...+...B...+H_(2)O II.underset((hot and conc.))(6NaOH)+3Cl_(2)rarr...C...+...D...+3H_(2)O Here, A, B, C and D refer to
Answer» SOLUTION :N//A

Discussion

24.	Iodine is more soluble in aqueous solution of KI because it forms solubel
Answer» `KI_(2)` `KI_(3)` `KI_(4)` `K_(2)I_(2)` Solution :`I_(2)` forms SOLUBLE `Kl_(3)` COMPOUND with KI

Discussion

25.	Iodine is liberated on adding potassium iodide solution to solution(s) of
Answer» `ZnCl_2` `FeCl_3` `CuSO_4` `AlCl_3` SOLUTION :`FeCl_3 + Kl rarr FeCl_2 + I_2 + KCL , CuSO_4 + KI rarr CuI + I_2 + K_2SO_4`

Discussion

26.	Iodine is formed when potassium iodide reacts with
Answer» `(NH_4)_2 SO_4` `CuSO_4` `FeSO_4` `ZnSO_4` ANSWER :B

Discussion

27.	Iodine is formed when potassium iodide reacts with a solution of:
Answer» `ZnSO_4` `CuSO_4` `FeSO_4` `(NH_4)_2SO_4` ANSWER :B

Discussion

28.	(i)Though Mg(OH)_2 is insoluble, Mg^2+ does not get precipitated in the group III. Explains(ii)When a chloride salt is heated with conc. H_2SO_4 Het gas is erelved whereas when a bromide salt is heated with conc. H_2SO_4, Bi gas is evolved. Why?
Answer» Solution :(i)The group III ragent is saturated `NH_4Cl` and `NH_4OH`.`NH_4Cl` being a STRONG eletrolyte DISSOCIATE completely and supresses the dissociation of the weak electrolyte `NH_4OH` HENCE the concentration Of OHis reduced and is insuuficent to overcome the Higher `K_spofMg(OH)_2` <BR>(ii)`Cl^(-)H_2SO_4to HCl+HSO_4` `In the case of abromide salt HBr formed is a reducing agent CONC. `H_2SO_4`oxidation the HBr to `Br_2` `Br^(-)+H_2SO_4toHBr+H_2SO_4` `2HBr+ H_2SO_4toBR_2uarr+SO_2+2H_2O`

Discussion

29.	IUFAC name of K_3[Co(NO_2)_6] is _____.
Answer» SOLUTION :POTASSIUM HEXANITROCOBALTATE (III)

Discussion

30.	Iodine is decolourised by :
Answer» `ZnCl_2` `HgCl_2` `SnCl_2` `AlCl_3` ANSWER :C

Discussion

31.	Iodine imparts brown colour to:
Answer» Water Benzene Alcohol Chloroform Answer :C

Discussion

32.	(i)"Tetragens"""(a)"Oxygen" (ii)"Icosagens"""(b)"Carbon"(iii)"Chalcogens"""©"Nitrogen"(iv)"Pnictogens"""(a)"Boron"
Answer» ANSWER :A::B::D

Discussion

33.	It was found that the solution of cane-sugar in water was hydrolysed to the extent of 25% in 60 minutes. Calculate the time taken for the sugar to be 50% hydrolysed, assuming that the reaction is of the first order.
Answer» ANSWER :145 MINUTES

Discussion

34.	It was found that in 30 unit cells of ZnS, four atoms are of trivalent metal. How many vacant tetrahedral voids are present in 30 unit cells of ZnS?
Answer» `2` `62` `122` `126` Solution :Total VACANT `=30xx4+2=122`

Discussion

35.	Iodine (I_(2)) and bromine (Br_(2)) are added to a solution containing iodine and bromide (Br^(-)) ions. What reaction would occur if the concentration of each species is 1M? The electrode potentials for the reaction are: E_(I_(2)//I^(-))^(@)=0.54V,E_(Br_(2)//Br^(-))^(@)=1.08V
Answer» Solution :The reaction can be either `Br_(2)+2I^(-)to2Br^(-)+I_(2)` or `I_(2)+2Br^(-)to2I^(-)+Br_(2)` For 1st reaction, E.M.F.`=E_(Br_(2)//Br^(-))^(@)-E_(I_(2)//I^(-))^(@)=1.08-0.54=0.54V` For 2ND reaction, E.M.F.`=E_(I_(2)//I^(-))^(@)-E_(Br_(2)//Br^(-))^(@)=0.54-1.08=-0.54V` As E.M.F. is POSITIVE for the 1st reaction, hence the cell reaction is `Br_(2)+2I^(-)to2Br^(-)+I_(2)`.

Discussion

36.	It was found that for a reaction, on changin the temperature the t_(1//2) value get decreased. Hence it can be said that
Answer» `T_(2)gtT_(1)` Reaction is exothermic `T_(2)gtT_(1)` Reaction is endothermic `T_(2)gtT_(1)` Reaction may be endothermic or exothermic None of these Solution :(I) Endo : A+Energy `to` PRODUCT `r_(f)=K_(f)[A]^(1),(t_(1/2))=[0.693/(K_(f))]` if tem `uarr` then `r_(f)uarr, K_(f)uarr,(t_(1/2))darr` (II) Exop `ATO` Product + Energy , `r_(f)=K_(f)[A]^(1)(t_(1/2))=(0.693/(K_(f)))` If `Tuarr,r_(f)darr,K_(f)darr,(t_(1/2))uarr` (III) But for both Exo & Endo themr if `Tuarr` then `K_(f)uarr` & `(t_(1/2))darr`

Discussion

37.	Iodine gets 5% dissociated into atoms when 1.0 mole of I_(2)(g) is introduced into an evacuated flask of 1L capacity at 150 K. The K_(c ) for the reaction.I_(2)(g)hArr 2I(g) at 1500 K is :
Answer» `1.05xx10^(-2)` `2.1xx10^(-2)` `10.5` 21 Solution :`{:(I_(2)(g),hArr,2I(g),),("Initial conc.",,1,0),("EQUAL conc.",,1-alpha,2ALPHA):}` `K_(c ) =((2alpha)^(2))/(1-alpha)` `=((2xx0.05)^(2))/((1-0.05))` `=((0.1)^(2))/(0.95)=1.05xx10^(-2)`

Discussion

38.	if two litres of air is passes repeatedly over heated copper and heated Mg till no further reduction in volume finally obtained will be approximately:
Answer» 200 mL 20mL Zero 10 mL Answer :B

Discussion

39.	It takes 0.15 mole of ClO^(-) to oxidize 12.6 g of chromium oxide of a specific formula to Cr_(2)O_(7)^(2-) ClO^(-) became Cl^(-) . The formula of the oxide is (atomic weight of Cr= 52 , O = 16)
Answer» `CrO_(3)` `CrO_(2)` `CrO_(4)` `CRO` SOLUTION :N/A

Discussion

40.	Iodine has +7 oxidation state in :
Answer» `HIO_4` `H_3IO_5` `H_5IO_6` All Answer :D

Discussion

41.	It states that matter can neither be created nor destroyed. This law was put forth by Antoine Lavoisier in 1789 . He performed rections for reaching to the above conclusion. This law formed the for several later developments in chemistry . Infact , this was the result of exact measurement of masses of reactants and products, and carefully planned experiments performed by Lavoisier 6.3 g of sodium bicarbonate is added to 15 g acetic acid solution .CO_(2) formed is allowed to escape. The weight of the solution left is 18 gram . What is the mass of CO_(2) formed.
Answer» ANSWER :`3.3` GM

Discussion

42.	Iodine imparts brown colour to
Answer» Water ETHER ALCOHOL Chloroform SOLUTION :IODINE is SLIGHTLY soluble in water, alcohol, ether giving light brown solution

Discussion

43.	Iodine gives blue colour with
Answer» `Cl_2` `F_2` Starch Litmus Answer :C

Discussion

44.	It states that matter can neither be created nor destroyed. This law was put forth by Antoine Lavoisier in 1789 . He performed rections for reaching to the above conclusion. This law formed the for several later developments in chemistry . Infact , this was the result of exact measurement of masses of reactants and products, and carefully planned experiments performed by Lavoisier. What weight of silver nitrate will react with 0.585 g NaCl to produce 1.435 g AgCl and 0.85 g NaNO_(3)
Answer» ANSWER :`1.70 GM

Discussion

45.	Iodine forms I_(3)^(-) but F_(2) does not form F_(3)^(-) ions. Why ?
Answer» Solution :`I_(2)` , because of the presence of vacant d-orbitals, `I_(2)` ACCEPTS electrons from `I^(-)` ions to FORM `I_(3)^(-)` ions but `F_(2)` because of the absence of d-orbitals does not accept electrons from `F^(-)` ions to form `F_(3)^(-)` ions.

Discussion

46.	It requires 40.0mL of 0.50 M Ce^(4+) to titrate 10 mL of 1.0MSn^(2+) to Sn^(4+). What is the oxidation state of cerium in the reduced product?
Answer» `+2` `+3` `+6` none Answer :B

Discussion

47.	Iodine forms I_3^(-)but F_2 does not form F_(3)^(-) ions. Why?
Answer» SOLUTION :IODINE FORMS `I_(3)^(-)` by accepting ELECTRONS from `I^-`in its vacant d-orbitals but `F_2` due to the ABSENCE of vacant d-orbitals does not accept electrons from `F^-` to form `F_3^-`ions.

Discussion

48.	Iodine exists as-
Answer» polar MOLECULAR SOLID ionic acid nonpolar molecular solid HYDROGEN bonded molecular solid ANSWER :C

Discussion

49.	It os practically difficult to calculate the equivalent conductivity of a weak electrolyte in aqueous solutions. Comment.
Answer» Solution :Equivalent CONDUCTANCE ` = (k xx 1000) `/ normality. The extent of DISSOCIATION of a wea ELECTROLYTE is less. Accordingly the number of ions furnished in aqueous solution is less. The specific CONDUCTIVITY (k) of a weak electrolyte is in the order `10^(-2)S m^(-1)` of or less. Sincek is less, it is difficult to calculate equivalent conductivity of a weak electrolyte.

Discussion

50.	Iodine displaces chlorine from which one of the compounds:
Answer» KCL `CaCl_2` `CCl_4` `KClO_3` ANSWER :B

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Iodine oxidises S_(2)O_(3)^(2-) ion to 'X', change in oxidation state of sulphur

IUPAC name of acetic acid is :﻿

Iodine oxidises S_2O_3^(2-)ion to:

Iodine molecules are held in the crystals lattice by

IUPAC name for the amine CH_(3)-underset(CH_(3))underset(|)(N)-underset(C_(2)H_(5))underset(|)overset(CH_(3))overset(|)(C)-CH_(2)-CH_(3) is ………

Iodine molecules are held in the crystals lattice by ……

Iodine may be liberated from sodium iodate by:

IUPAC name of 1^(0) amine is

Iodine is violet coloured. Why?

Iodine is soluble in water in the presence of :

IUPAC name m-toluic acid is

Iodine is ______type solid.

IUPACnamefor theamine CH_(3)- underset(CH_(3))underset(|)N - underset(C_(2)H_(5))underset(|) overset(Ch_(3))overset(|)C-CH_(2)-CH_(5) is

Iodine is released when potassium iodine reacts with

Iodine is placed between two liquids C_6H_6 and water:

IUPAC name for the amine {:(""CH_(3)),("|"),(CH_(3)-N-C-CH_(2)-CH_(3)),("||"),(""CH_(3)CH_(2)H_(5)):} is

Iodine is more soluble in KI than in water. Why ?

IUPAC name ethyl menthyl amineis

Iodine is more soluble in alcohol than in carbon tetrachloride because

IUPAC name crotonaldehyde is _____.

Iodine is libereated when Cu^(2+)reacts with KI but chlorine isnot liberatedwhen Cu^(2+)is allowed to react with KCI. Why ?

IUPAC has recommended the use of the lerm conductivity over specific conductivity.

I.underset((cold and dlll))(2NaOH)+Cl_(2)rarr...A...+...B...+H_(2)O II.underset((hot and conc.))(6NaOH)+3Cl_(2)rarr...C...+...D...+3H_(2)O Here, A, B, C and D refer to

Iodine is more soluble in aqueous solution of KI because it forms solubel

Iodine is liberated on adding potassium iodide solution to solution(s) of

Iodine is formed when potassium iodide reacts with

Iodine is formed when potassium iodide reacts with a solution of:

(i)Though Mg(OH)_2 is insoluble, Mg^2+ does not get precipitated in the group III. Explains(ii)When a chloride salt is heated with conc. H_2SO_4 Het gas is erelved whereas when a bromide salt is heated with conc. H_2SO_4, Bi gas is evolved. Why?

IUFAC name of K_3[Co(NO_2)_6] is _____.

Iodine is decolourised by :

Iodine imparts brown colour to:

(i)"Tetragens"""(a)"Oxygen" (ii)"Icosagens"""(b)"Carbon"(iii)"Chalcogens"""©"Nitrogen"(iv)"Pnictogens"""(a)"Boron"

It was found that the solution of cane-sugar in water was hydrolysed to the extent of 25% in 60 minutes. Calculate the time taken for the sugar to be 50% hydrolysed, assuming that the reaction is of the first order.

It was found that in 30 unit cells of ZnS, four atoms are of trivalent metal. How many vacant tetrahedral voids are present in 30 unit cells of ZnS?

Iodine (I_(2)) and bromine (Br_(2)) are added to a solution containing iodine and bromide (Br^(-)) ions. What reaction would occur if the concentration of each species is 1M? The electrode potentials for the reaction are: E_(I_(2)//I^(-))^(@)=0.54V,E_(Br_(2)//Br^(-))^(@)=1.08V

It was found that for a reaction, on changin the temperature the t_(1//2) value get decreased. Hence it can be said that

Iodine gets 5% dissociated into atoms when 1.0 mole of I_(2)(g) is introduced into an evacuated flask of 1L capacity at 150 K. The K_(c ) for the reaction.I_(2)(g)hArr 2I(g) at 1500 K is :

if two litres of air is passes repeatedly over heated copper and heated Mg till no further reduction in volume finally obtained will be approximately:

It takes 0.15 mole of ClO^(-) to oxidize 12.6 g of chromium oxide of a specific formula to Cr_(2)O_(7)^(2-) ClO^(-) became Cl^(-) . The formula of the oxide is (atomic weight of Cr= 52 , O = 16)

Iodine has +7 oxidation state in :

Iodine imparts brown colour to

Iodine gives blue colour with

Iodine forms I_(3)^(-) but F_(2) does not form F_(3)^(-) ions. Why ?

It requires 40.0mL of 0.50 M Ce^(4+) to titrate 10 mL of 1.0MSn^(2+) to Sn^(4+). What is the oxidation state of cerium in the reduced product?

Iodine forms I_3^(-)but F_2 does not form F_(3)^(-) ions. Why?

Iodine exists as-

It os practically difficult to calculate the equivalent conductivity of a weak electrolyte in aqueous solutions. Comment.

Iodine displaces chlorine from which one of the compounds:

IUPAC name of acetic acid is :