94420 + Interview Questions in Chemistry in Class 12

1.	Among [Ag(NH_(3))_(2)]Cl, [Ni(CN)_(4))^(2-) and [CuCl_(4)]^(2-) which has square planar geometry ?
Answer» SOLUTION :`[NI(CN)_(4)]^(2-)` has square PLANAR geometry.

Discussion

2.	Among acetic acid , phenol and n-hexanol, which of the compounds will react with NaHCO_3 solution to give sodium salt and CO_2
Answer» ACETIC ACID phenol n-hexanol acetic acid and phenol Answer :A

Discussion

3.	Among 3d-, 4d- and 5d- series elements, which elements hasthe least and which has the highest I_(l)?
Answer» Solution :Among first three SERIES of d-block, first ionisation energy is LEAST for LANTHANUM and is highest for MERCURY.

Discussion

4.	Among 1M solution of glucose , NaCl, FeCl_3, CaCl_2, which one has the (a) highest boiling point (b) lowest boiling point ?
Answer» SOLUTION :(a) `FeCL_3sol^@` (B) GLUCOSE solution .

Discussion

5.	Among 1% solutions of urea. Glucose and sucrose
Answer» the vapour PRESSURE and freezing point are the LOWEST for UREA the vapour pressure and BOILING point are the lowest for urea the depression in freezing point is the highest for urea the elevation in boiling point is the highest for urea Answer :A::C::D

Discussion

6.	Amolal solution is one that contains 1 mole of a solute in
Answer» 1000 G of the SOLVENT ONE LITRE of the solvent one litre of the solution 22.4 litres of the solution Answer :A

Discussion

7.	Among 1% solution of urea, glucose and sucrose
Answer» the vapour PRESSURE and freezing point are the lowest for urea the vapour pressure and BOILING point are the lowest for urea the DEPRESSION in freezing point is the highest for urea the elevation in boiling point is the highest for urea. Answer :A::C::D

Discussion

8.	Ammonolysis of hydroxyl compounds is called ………………… reaction.
Answer» ANSWER :SABATIER -mailhe

Discussion

9.	Ammonolysis of methyl chloride can be used to obtain pure methylamine.
Answer» ANSWER :F

Discussion

10.	Ammonta has higher boiling point than expected because :
Answer» 1. It FORMS `NH_(4)OH` with WATER 2. its density decreases on freezing 3. it has strong intermolecular covalent BONDS 4. it has strong intermolecular hydrogen bonds. SOLUTION :The higher boiling point of ammonia is because of strong intermolecular hydrogen bonds.

Discussion

11.	Ammonolysis of alkyl halides to give amines is an example of_____reactions.
Answer» SOLUTION :NUCLEOPHILIC SUBSTITUTION

Discussion

12.	Ammonolysis of an ester gives,
Answer» AMINE AMIDE Uride None Answer :B

Discussion

13.	Ammonium sulphide and ammonium selenide onheating dissociates as (NH_4)_2S_((s)) hArr 2NH_(3(g)) + H_2S_((g)) , K_(p_1) = 9xx10^(-3) "atm"^3 (NH_4)_2Se_((s)) hArr 2NH_(3(g)) + H_2Se_((g)), K_(p_2) = 4.5xx10^(-3) "atm"^3 The total pressure over the solid mixture at equilibrium is
Answer» <P>0.15 atm 0.3 atm 0.45 atm 0.6 atm Solution :`(NH_4)_2Se_((s)) hArr UNDERSET(2p)(2NH_(3(G)))+underset"p"(H_2S_((g)))` `(NH_4)_2Se_((s)) hArr underset"2q"(2NH_(3(g))) + underset"q" (H_2Se_((g)))` `K_(p_1)=(p_(NH_3))^2 .p_(H_2S)=(2p+2q)^2. p=9.0xx10^(-3)` `K_(p_2)= (p_(NH_3))^2. p_(H_2Se) = (2p+2q)^2. q= 4.5xx10^(-3)` `therefore p/q=2 RARR p=2q` `therefore K_(p_1)=(2p+p)^2 . p = 9.0xx10^(-3)` `therefore` p=0.1 atm and `q=0.1/2`=0.05 Total pressure = 2p+2q+p+q=3p+3q = 3 x 0.1 + 3 x 0.05 = 0.45 atm

Discussion

14.	Ammonium salts decompose quite readily on heating : (i) Ammonium salt of weak oxidizing anion (e.g. Cl^(-), CO_(3)^(2-), SO_(4)^(2-)) overset("heat")rarr Gas X (ii) Ammonium salt of strong oxidizing anion (e.g. NO_(2)^(-), NO_(3)^(-), CiO_(4)^(-), Cr_(2)o_(7)^(2-) overset("heat")rarr Gas Y/Z Identify X, Y, Z
Answer» `N_(2), NH_(3), N_(2)O` `NH_(3), N_(2), N_(2)O` `N_(2)O, NH_(3), N_(2)` `NO, NH_(3), N_(2)O` Answer :B

Discussion

15.	Ammonium salt of bezoic acid is heated strongly with P_2O_5 and the product so formed is reduced and then treated with NaNO_2"/"HCl at low temperature. The final compound formed is
Answer» BENZENE DIAZONIUM chloride Benzyl alcohal Phenol Nitrosobenzene Answer :B

Discussion

16.	Ammonium salt of benzoic acid isheated strongly and the product so formed is reduced and then treated with NaNO_(2)//HCl at low temperature. The final compound formed is …………
Answer» Benzene diazonium chloride Benzyl alcohol Phenol Nitrosobenzene Solution :`C_(6)H_(5)COONH_(4)underset("Heat")OVERSET(P_(2)O_(5))(to)C_(6)H_(5)-C-=Noverset(LiAlH_(4))(to)C_(6)H_(5)CH_(2)NH_(2)overset(HNO_(2))(to) C_(6)H_(5)CH_(2)OH`

Discussion

17.	Ammonium salt are oxidised in the soil to nirites by:
Answer» ANSWER :B

Discussion

18.	Ammonium persulphate solution on heating under reduced pressure gives :
Answer» `H_2O_2` `O_2` `H_2` `(NH_4)_2SO_4` ANSWER :A

Discussion

19.	Ammonium nitrate on heating gives
Answer» NO `N_(2)` `N_(2)O` `N_(2)O_(4)` ANSWER :3

Discussion

20.	Ammonium molybdate test is used for the estimation of :
Answer» `PO_(4)^(3-)` `NO_(3)^(-)` `SO_(3)^(2-)` `SO_(4)^(2-)` ANSWER :A

Discussion

21.	Ammonium molybdate is used to test the radical
Answer» `PO_(4)^(3-)` `AsO_(4)^(3-)` `Cu^(2+)` `AG^(o+)` Solution :Both `PO_(4)^(3-) and AsO_(4)^(3-)` GIVE yellow ppt with ammonium molybdate

Discussion

22.	Ammonium ion is
Answer» neither an acid nor BASE both an acid and a base a conjugate acid a conjugate base Solution :Acid`hArr`conjugate base`+H^(o+)` `NH_(4)^(+)hArrNH_(4)+H^(+)` Ammonium ion is a conjugate acid.

Discussion

23.	Ammonium hydroxide is a weaker base because it is :
Answer» UNSTABLE COVALENT COMPOUND only SLIGHTLY ionises none of these. Answer :C

Discussion

24.	Ammonium hydroxide is a weak base because
Answer» It has low VAPOUR pressure It is only slightly IONIZED It is not a HYDROXIDE of any metal It has low density Solution :It is WEAK electrolyte since slightly ionized.

Discussion

25.	Ammonium hydrogen sulfide dissociates as follows NH_4HS(s) hArr H_2S(g) +NH_3(g) if solid NH_4 HS is placed in an evacuated flask at a certain temperature, it will dissociate until the total gas pressure is 500 torr. Calculate the following. (a) Equilibrium constant for the dissociation reaction (b) if the additional NH_3 is introduced into the equilibrium mixture without change in temperature until the partial pressure of ammonia is 700 torr. (i) Whatis the partial pressure of H_2O under these conditions (ii) What is the total pressure in the flask ?
Answer» ANSWER :0.329 ATM (a) `0.108 atm^2` (b) 0.117 atm (ii) 789 TORR

Discussion

26.	Ammonium hydrogen sulphide dissociates as follows : NH_(4) HS(s) hArr H_(2) S(g) = NH_(3)(g) If solid NH_(4) HS is placed in an evacuated flask at a certain temperature, it will dissociate until the total gas pressure is 500 torr. Calculate the following : ( a) Equilibrium constant for the dissociation reaction ( b) If the additional NH_(3) is introduced into the equilibrium mixture without change intemperature until the partial pressure of ammonia is 700 torr. (i) What is the partial pressure of H_(2)S under the conditions. (ii) What is the total pressure in the flask ?
Answer» <P> Solution :SINCE, `P_(H_(2)S)= P_(NH_(3)) = ( 250)/( 760) = 0.329 `atm ( a) `K_(p ) =P_(H_(2)S) P_(NH_(3)) = 0 .108"atm"^(2)` ( b) `K_(p ) = P_(H_(2)S ) P_(NH_(3))` `P_(H_(2)S) = ( 0.108)/( 700 // 760 ) = 0.117` atm (ii)Total pressure `= P_(H_(2) S) + P_(NH_(3)) = 789 ` torr

Discussion

27.	Ammonium formate on heating yields:
Answer» Ammonia Formamide Formic ACID AMMONIUM CARBONATE ANSWER :B

Discussion

28.	Ammonium dichromate is used in some fireworks. The green coloured powder blown is:
Answer» `CrO_3` `Cr_2O_3` CR `CRO(O_2)` ANSWER :B

Discussion

29.	Ammonium dichromate is used in fireworks. The green coloured blown in air is :
Answer» `CrO_(3)` `Cr_(2)O_(3)` CR `CrO(O)_(2)` Solution :`(NH_(4))_(2)Cr_(2)O_(7) to Cr_(2)O_(3) + Cr_(2)O_(3) + N_(2) + 4H_(2)O`

Discussion

30.	Ammonium cyanide is a salt of NH_(4)OH(K_(b)=1.8xx10^(-5)) and HCN (K_(a)=4.0xx10^(-10)). The hydrolysis constant of 0.1 M NH_(4)CN at 25^(@)C is :
Answer» `1.4` `7.2xx10^(-15)` `7.2xx10^(-1)` `1.4xx10^(-6)` SOLUTION :`K_(H)=(K_(w))/(K_(a)xx K_(b))` `=(1xx10^(-14))/(4.0xx10^(-10)xx1.8xx10^(-5))=1.4`

Discussion

31.	Ammonium compound which upon heating does not give ammonia is :
Answer» `(NH_(4))_(2)SO_(4)` `(NH_(4))_(2)CO_(3)` `NH_(4)NO_(2)` `NH_(4)Cl` SOLUTION :`NH_(4)NO_(2)overset("HEAT")to N_(2)+2H_(2)O`

Discussion

32.	Ammonium chloride,when dissolved in water , leads to a cooling sensation . The dissolution of ammonium chloridae at constant temperature is accompanied by q
Answer» increases in entropy decreases in entropy no CHANGE in entropy no change in enthalpy Solution :in dissolution , SOLID CHANGES to ions in solution , which have more RANDOMNESS

Discussion

33.	Ammonium compound not used as a fertilizer is
Answer» `(NH_4)_2SO_4` `(NH_4)_2CO_3` `NH_4NO_3` `CAN ( CALCIUM AMMONIUM NITRATE )` ANSWER :B

Discussion

34.	Ammonium chloride is removed from its mixture by:
Answer» Filtration Distillation Sublimation A magnet Answer :C

Discussion

35.	Solid Ammonium carbamate dissociates as: NH_(2)COONH_(4)(s)hArr2NH_(3)(g)+CO_(2)(g). In a closed vessel, solid ammonium carbonate is in equilibrium with its dissociation products. At equilibrium, ammonia is added such that the partial pressure of NH_(3) at new equilibrium now equals the original total pressure. Calculate the ratio of total pressure at new equilibrium to that of original total pressure. Also find the partial pressure of ammonia gas added.
Answer» `(27)/(31)` `(31)/(27)` `(4)/(9)` `(41)/(9)` ANSWER :B

Discussion

36.	Ammonium cations can be detected using the complex
Answer» `[Cu(NH_3)_4]^(2+)` `[HgI_4]^(2-)` `[AG(CN)_2]^-` `[HgI_2]` Answer :B

Discussion

37.	Ammonium carbamate when heated to 200^(@)C gives a mixture of NH_(3) and CO_(2) vapours with a density of 16.0. What is the degree of dissociation of ammonium carbamate? (Given vapour density of ammonium carbamate is 48)
Answer» `3//2` `1//2` 2 1 Solution :`{:(,NH_(2)COONH_(4),rarr,2NH_(3),+,CO_(2)),("Initial","1 MOLE",,,,),("After disso.",1-alpha,,2alpha,,alpha):}` Total = `1+2alpha` THEORETICAL, density `(d)prop(1)/((1+2alpha)V)` `THEREFORE (D)/(d)=1+2alpha` or, `alpha=(1)/(2)((D-d)/(d))=(1)/(2)((48-16.0)/(16.0))=1.0`

Discussion

38.	Ammonium carbamate is :
Answer» `(HN_4)_2CO_3` `NH_4COONH_2` `NH_2CONH_2` `HCOONH_4` ANSWER :B

Discussion

39.	Ammonium carbamate dissociates on heating as: NH_(2)COONH_(4)(g)hArr2NH_(3)(g)+CO_(2)(g) The equilibrium constant K_(p) for the reaction, at some temperature is 3.2xx10^(-5)atm^(3). Calculate the partial pressure of NH_(3) in the equilibrium system at the same temperature.
Answer» <P>`2.0xx10^(-2)atm` `4,0xx10^(-2)atm` `3.2xx10^(-2)atm` `6.4xx10^(-2)` atm SOLUTION :`NH_(2)COONH_(4)(s)hArrunderset(2p)(2NH_(3)(G))+UNDERSET(p)(CO_(2)(g))` `K_(p)=P_(NH_(3))^(2)xxp_(CO_(2))=(2p)^(2)xx=3.2xx10^(-5)atm^(3)` `impliesp=2xx10^(-2)atm,""p_(NH_(3))=2xx2xx10^(-2)atm`

Discussion

40.	Ammonium bydrogen sulfied, NH_(4)HS is unstable at room temperature and decomposes as : NH_(4)HS (s) hArr NH_(3) (g) + H_(2)S (g) Then which of the following will produce less H_(2)S (g) :
Answer» Removing some of `NH_(3)` form flask. Removing some of `NH_(4)HS (s)`. On increasing pressure by DECREASING volume Increasing TEMPERATURE. Solution :(1) Removing product will shift EQUILIBRIUM forward. (2) Adding or removing a SOLID doesn't effect equilibrium (4) Decomposition reactions are endothermic in nature, increasing temperature will shift equilibrium forward.

Discussion

41.	Ammonium acetate which is 0.01 M , is hydrolysed to 0.001 M concentration . Calculate the change in pH in 0.001 M solution , if initially pH = pK_(a)
Answer» 5 10 100 1 Solution :`CH_(3)COO^(-)+NH_(4)^(+)+H_(2)O hArr CH_(3)COOH+NH_(4)OH` `{:("Initial",0.01M,0.01M,(0.01-0.001)M,(0.01-0.001)M),("At eqm.",0.001M,0.001M,=0.009M,=0.009M):}` `K_(h)=([CH_(3)COOH][NH_(4)OH])/([CH_(3)COO^(-)][NH_(4)^(+)])=((0.009)^(2))/((0.001)^(2))=10^(2)` `K_(h)=(K_(W))/(K_(a) xx K_(b))` `:. K_(b)=(K_(w))/(K_(a)xxK_(h))=(10^(-14))/(K_(a)xx 10^(2))=(10^(-16))/(K_(a))` `[H^(+)]=sqrt((K_(a)xxK_(w))/(K_(b)))=sqrt((K_(a)xx10^(-14))/(10^(-16)//K_(a)))=10K_(a)` `(pH)_("Initial")=pK_(a)` `(pH)_("Final")=-log[H^(+)]=-log(10K_(a))=pK_(a)-1` Change in pH `=(pH)_("Final")-(pH)_("Inital")` `=pK_(a)-1-pK_(a)= -1`

Discussion

42.	Ammonium acetate reacts with acetic acid at 110^(@)C to give
Answer» Urea Formamide ACETIC ANHYDRIDE ACETAMIDE ANSWER :D

Discussion

43.	Ammonical cuprous chloride will give red precipitate with which one of the following
Answer» `CH_3-C-=C-CH_3` `CH_3-CH=CH_2` `CH_3-C-=CH` `CH_3-CH=CH-CH_3` ANSWER :C

Discussion

44.	Ammonium acetate on heating gives :
Answer» Acetamide Acetic anhydride Acetaldehyde AMMONIA Acetic acid and ammonia . Solution :`CH_(3)COONH_(4)overset("Heat")tounderset("Acetamide")(CH_(3)CONH_(2))`

Discussion

45.	Ammonical AgNO_(3) gives white ppt after with any compound then this reflects the presence of
Answer» One-`CHO` group One triple bond A terminal ALKYNE Compound is unsaturated Solution :Terminal alkyne give `AgNO_(3)` (Ammonical) test.

Discussion

46.	Ammonical CuCl absorbs :
Answer» `CO_2` `SO_2` `H_2SO_4` `CO` ANSWER :D

Discussion

47.	Ammonium and phosphate resemble each other in:
Answer» SOLUBILITY in water forming SALT with acid stability reducing character Answer :B

Discussion

48.	Ammoniacal solution of MgSO_(4) in presence of NH_(4)Cl is heated with Na_(2)HPO_(4), a white precipitate is formed of
Answer» `Mg(NH_(4))PO_(4)` `Mg_(3)(PO_(3))_(2)` `MgSO_(4)MgCl_(2)` `MgSO_(4)MgPO_(4)` ANSWER :A

Discussion

49.	Ammoniacal solution of silver nitrate is known as _____.
Answer» SOLUTION :Tollen.s REAGENT

Discussion

50.	Ammonia undergoes self dissociation according to the reaction 2 NH_(3(l)) hArr NH_(2(am))^(+)+NH_(2(am))^(-)where am, stands for ammoniated. When 1 mol of NH_(4) CI is dissolved in 1 kg of liquid ammonia, the b.p. at 760 torr is observed as -32.7^(@)C (normal boiling b.p. of NH_(3(l)) is 33.4^(@)C). What conclusion is reached about the nature of thesolution
Answer» `NH_(4)` CI is completely dissociated in `NH_(3)` `NH_(4)` CI is partially dissociated in `NH_(3)` `NH_(4)`CI is not dissociated in `NH_(3)` BOILING POINT is not raised Solution :`NH_(4)Cl` is a STRONG acid in liq. `NH_(3)`. SINCE, it ionizes to give `NH_(4)^(+)` (which is cation of the the SOLVENT). `NH_(4)Cl hArr NH_(4)^(+)+Cl^(-)`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Among [Ag(NH_(3))_(2)]Cl, [Ni(CN)_(4))^(2-) and [CuCl_(4)]^(2-) which has square planar geometry ?

Among acetic acid , phenol and n-hexanol, which of the compounds will react with NaHCO_3 solution to give sodium salt and CO_2

Among 3d-, 4d- and 5d- series elements, which elements hasthe least and which has the highest I_(l)?

Among 1M solution of glucose , NaCl, FeCl_3, CaCl_2, which one has the (a) highest boiling point (b) lowest boiling point ?

Among 1% solutions of urea. Glucose and sucrose

Amolal solution is one that contains 1 mole of a solute in

Among 1% solution of urea, glucose and sucrose

Ammonolysis of hydroxyl compounds is called ………………… reaction.

Ammonolysis of methyl chloride can be used to obtain pure methylamine.

Ammonta has higher boiling point than expected because :

Ammonolysis of alkyl halides to give amines is an example of_____reactions.

Ammonolysis of an ester gives,

Ammonium sulphide and ammonium selenide onheating dissociates as (NH_4)_2S_((s)) hArr 2NH_(3(g)) + H_2S_((g)) , K_(p_1) = 9xx10^(-3) "atm"^3 (NH_4)_2Se_((s)) hArr 2NH_(3(g)) + H_2Se_((g)), K_(p_2) = 4.5xx10^(-3) "atm"^3 The total pressure over the solid mixture at equilibrium is

Ammonium salt of bezoic acid is heated strongly with P_2O_5 and the product so formed is reduced and then treated with NaNO_2"/"HCl at low temperature. The final compound formed is

Ammonium salt of benzoic acid isheated strongly and the product so formed is reduced and then treated with NaNO_(2)//HCl at low temperature. The final compound formed is …………

Ammonium salt are oxidised in the soil to nirites by:

Ammonium persulphate solution on heating under reduced pressure gives :

Ammonium nitrate on heating gives

Ammonium molybdate test is used for the estimation of :

Ammonium molybdate is used to test the radical

Ammonium ion is

Ammonium hydroxide is a weaker base because it is :

Ammonium hydroxide is a weak base because

Ammonium formate on heating yields:

Ammonium dichromate is used in some fireworks. The green coloured powder blown is:

Ammonium dichromate is used in fireworks. The green coloured blown in air is :

Ammonium cyanide is a salt of NH_(4)OH(K_(b)=1.8xx10^(-5)) and HCN (K_(a)=4.0xx10^(-10)). The hydrolysis constant of 0.1 M NH_(4)CN at 25^(@)C is :

Ammonium compound which upon heating does not give ammonia is :

Ammonium chloride,when dissolved in water , leads to a cooling sensation . The dissolution of ammonium chloridae at constant temperature is accompanied by q

Ammonium compound not used as a fertilizer is

Ammonium chloride is removed from its mixture by:

Ammonium cations can be detected using the complex

Ammonium carbamate when heated to 200^(@)C gives a mixture of NH_(3) and CO_(2) vapours with a density of 16.0. What is the degree of dissociation of ammonium carbamate? (Given vapour density of ammonium carbamate is 48)

Ammonium carbamate is :

Ammonium carbamate dissociates on heating as: NH_(2)COONH_(4)(g)hArr2NH_(3)(g)+CO_(2)(g) The equilibrium constant K_(p) for the reaction, at some temperature is 3.2xx10^(-5)atm^(3). Calculate the partial pressure of NH_(3) in the equilibrium system at the same temperature.

Ammonium bydrogen sulfied, NH_(4)HS is unstable at room temperature and decomposes as : NH_(4)HS (s) hArr NH_(3) (g) + H_(2)S (g) Then which of the following will produce less H_(2)S (g) :

Ammonium acetate which is 0.01 M , is hydrolysed to 0.001 M concentration . Calculate the change in pH in 0.001 M solution , if initially pH = pK_(a)

Ammonium acetate reacts with acetic acid at 110^(@)C to give

Ammonical cuprous chloride will give red precipitate with which one of the following

Ammonium acetate on heating gives :

Ammonical AgNO_(3) gives white ppt after with any compound then this reflects the presence of

Ammonical CuCl absorbs :

Ammonium and phosphate resemble each other in:

Ammoniacal solution of MgSO_(4) in presence of NH_(4)Cl is heated with Na_(2)HPO_(4), a white precipitate is formed of

Ammoniacal solution of silver nitrate is known as _____.