94420 + Interview Questions in Chemistry in Class 12

1.	Solubility curve of Na_(2)SO_(4).10H_(2)O in water with temperature is given as
Answer» SOLUTION process is EXOTHERMIC Solution process is exothermic till `32.4^(@)C` and endothermic after `32.4^(@)C` Solution process is endothermic till `32.4^(@)` and exothermic thereafter Solution process is endothermic Solution :Below `34^(@)C, Na_(2)SO_(4).10H_(2)O` exists as such, since in this part solubility increases. This IMPLIES that process must be endothermic. Thereafter, solubility DECREASE with rise in temperature. It means that the solution process is exothermic. In fact after `34^(@)C` the substance exists in anhydrous state `Na_(2)SO_(4)`.

Discussion

2.	Solubility curve of a hydrated salt in water with temperature is given. The curve indicates that the solution process is
Answer» exothermic temperature exotehrmic till `60^(@)C` and ENDOTHERMIC after `60^(@)C` endothermic till `60^(@)C` and exothermic there-after endothermic Solution :Since solubility increases with INCREASE in temperature upto `60^(@)C`, the process is endothermic upto `60^(@)C`. After `60^(@)C` solubility DECREASES with increase in temperature, THUS after `60^(@)C`, the process is exothermic.

Discussion

3.	Solubility curve of Na_(2)SO_(4).10 H_(2)O in water with temperature is given as
Answer» `Delta H` is -ve after `34^(@)C` SOLUTION process is exothermic till `34^(@)C` and ENDOTHERMIC after `34^(@)C` solution process is endothermic till `34^(@)C` and exothermic thereafter `DELTAH` is-ve after `34^(@)C` Answer :A::C::D

Discussion

4.	Solubilities of three sparingly soluble salts XY(K_(sp)),XY_(2)(K'_(sp)) and X_(2)Y_(3)(K''_(sp)) are equal in water. What will be the correct order of their solubility products
Answer» `K_(sp)ltK'_(sp)ltK''_(sp)` `K_(sp)ltK''_(sp)ltK'_(sp)` `K''_(sp)ltK'_(sp)ltK_(sp)` `K''_(sp)ltK_(sp)ltK'_(sp)` Solution :Since for sparingly soluble SALTS, solubility will be less then one. Therefore as the POWERS of s increases in `K_(sp)` EXPRESSION, MAGNITUDE of `K_(sp)` will BECOME smaller.

Discussion

5.	Solubility and thermal stability both increase drown the group for (A.M.= Alkaline metal, A.E.M.=Alkaline earth metal) :
Answer» Hydrixide of A.E.M. [`M(OH_(2)`] FLUORIDES of A.M. (MF) Perchlorates of A.M. (`MClO_(4)`) Hydrides of N-family (`MH_(3)`) Answer :A

Discussion

6.	Solubilities of carbonates decrease down the magnesium group due to decrease in :
Answer» ENTROPY of SOLUTION formation lattice ENERGIES of solids hydration energies of cation inter-ionic attraction Answer :C

Discussion

7.	Solubbility product of PbCl_2 at 298K is 1.0 xx 10^-6. At this temperature solubility of PbCL_2 in mol per litre is :
Answer» `(1.0xx10^(-6))^(1/2)` `(1.0xx10^(-6))^(1/3)` `(0.25xx10^(-6))^(1/3)` `(0.25xx10^(-6))^(1/2)` ANSWER :C

Discussion

8.	Sols of metals like Cu, Ag, Au are prepared by
Answer» Peptisation Oxidation BREDIG's ARC method Mechanical grinding Answer :C

Discussion

9.	Sols of protein and starch are examples of ........
Answer» SOLUTION :LYOPHILIC SOLS ( or ) REVERSIBLE sols

Discussion

10.	Sols of gold, silver, platinum and copper are examples of ...............
Answer» SOLUTION : LYOPHOBIC SOLS ( or ) IRREVERSIBLE sols

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11.	Solids ice, glucose are examples of ………………….........
Answer» metallic SOLIDS ionic solids HYDROGEN bonded molecular solids non POLAR molecular solids SOLUTION :hydrogen bonded molecular solids

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12.	Solids have the following characteristics :
Answer» They have definite MASS, VOLUME and shape. INTERMOLECULAR DISTANCES are short. Intermolecular forces are strong. All the above. Answer :D

Discussion

13.	Solids for which physical properties like electric resistance or refractive index show different values when measured along different directions are called
Answer» PSEUDO solids Isotropic solids Polymorphic solids Anisotropic solids Answer :D

Discussion

14.	Solids can be classified into three types on the basis of their electrical conductivities. Namethree types on the basis of their electrical conductivities.
Answer» Solution :On the BASIS of ELECTRICAL conductivities, solids are CLASSIFIED into CONDUCTORS, insulators and semi-conductors.

Discussion

15.	Solids can be classified into three types on the basis of their electrical conductivities.i) Name three types of solids classified on the basis of electrical conductivities.
Answer» SOLUTION :CONDUCTORS, INSULATORS & SEMI conductors.

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16.	Solids are classified into two types. What are they?
Answer» SOLUTION :CRYSTALLINE and AMORPHOUS.

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17.	_____solids are isotropic in nature.
Answer» SOLUTION :AMORPHOUS SOLIDS

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18.	Solids are classified into two types.Give two examples.
Answer» SOLUTION :Crystalline-NaCl,KCL. Amorphous -PLASTIC,RUBBER.

Discussion

19.	Solidited Cubained from the reverberatory tumaca has bied appearance. This is due to
Answer» Evolution of `CO_2` gas Evolution of `SO_2` gas Due to EVAPORATION of VOLATILE MATERIALS Evolution of `NO_2` ANSWER :B

Discussion

20.	Solids are characterised by their properties :
Answer» Incompressibility Mechanical strength Crystalling NATURE All Answer :D

Discussion

21.	Solid phosphorus melts and vapourizes at high temperature. Gaseous phosphorus effuses at a rate that is 0.567 times that of Ne in the same apparatus under the same conditions. How many atoms are in a molecule of gaseous phosphorus.
Answer» ANSWER :2

Discussion

22.	_____solids are anisotropic in nature.
Answer» SOLUTION :CRYSTALLINE SOLIDS

Discussion

23.	Solid SO_(2) and solid NH_(3) are examples of
Answer» POLAR MOLECULAR SOLIDS. HYDROGEN BONDED molecular solids non-polar molecular solids. none of these. Answer :A

Discussion

24.	Solid NH_4HSis taken in an evacuated vessel and allowed to dissociate at a certaintemperature until the total gas pressure is 0.66 atm. What would be the value of K_pfor the following reaction?NH_4HS(s) iff NH_3(g) + H_2S(g)What would be the partial pressure of H_S if additional NH_3is introduced into the equilibrium mixture at the same temperature until the partial pressure of NH_3is 0.921 atm?
Answer» SOLUTION :0.1089 ATM

Discussion

25.	Solid PCl_(5) exists as :
Answer» `PCl_(5)` `PCl_(6)^(-)` `PCl_(4)^(+)+PCl_(6)^(-)` `PCl_(3)+P.` ANSWER :C

Discussion

26.	Solid PCl_(5) , exists as
Answer» `PCl_5` `PCl_4^+` `PCl_6^-` `PCl_4^+ and PCl_6^-` ANSWER :D

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27.	Solid NH_(3) solid CO_(2) are examples of
Answer» COVALENT solids polar MOLECULAR solids molecular solids IONIC solids Solution :polar molecular solids

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28.	Solid NaCl is a bad conductor of electricity because
Answer» solid NACL is COVALENT in solid NaCl there are strong ATTRACTIVE forces in solid NaCl there are no mobile ELECTRONS in solid NaCl there are no ions. Answer :B

Discussion

29.	Solid N_2 O_5 exists as NO_2^(oplus) NO_3^(Ө) and hence is called nitronium nitrate. The gas which is acidic in nature is.
Answer» `NO` `N_2 O` `NO_2` Both (a) and (B) ANSWER :C

Discussion

30.	Solid methane is
Answer» MOLECULAR solid ionic solid Covalent solid Not possible Answer :A

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31.	Solid NaCl is bad conductor of electricity because :
Answer» In SOLID there are no ions Solid NaCI is covalent In solid NaCI, there is no velocity of ions None Answer :C

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32.	Solid KmnO_(4) on heating with H_(2) forms
Answer» MNO KOH `H_(2)O` all of these ANSWER :D

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33.	Solid CO_2 is used as:
Answer» Poison Fire extinguisher Refrigerant Artificial respirant Answer :C

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34.	Solid CO_(2) is known as dry ice, because
Answer» It melts at `0^(@)C` it evaporates at `40^(@)C` It evaporates at `-78^(@)C` without melting Its boiling POINT is more than `199^(@)C` Solution :Solid `CO_(2)` is KNOWN as dry ice because it evaporates at `78^(@)C` without changing in the LIQUID state.

Discussion

35.	Solid CO_(2) is an example of …………….
Answer» COVALENT solid metallic solid molecular solid ionic solid Solution :Hint : Lattice POINTS are OCCUPIED by `CO_(2)` molecules

Discussion

36.	Solid CO_2 is an example of:
Answer» MOLECULAR CRYSTAL COVALENT crystal Metallic crystal IONIC crystal Answer :A

Discussion

37.	Solid Cl_(2)O_(6) exists as
Answer» `ClO_(2)^(+) , ClO_(4)^(-)` `ClO_(4)^(-)` `(ClO_(3))_(2)` NONE of these Solution :In SOLID state `Cl_(2)O_(6)` EXIST as a MIXTURE of `ClO_(2)^(o+), ClO_(4)^(o+)`

Discussion

38.	Solid carbondioxide and RMgX produces
Answer» alkanoic acid alkanal alkanone alkyl alkanoate Solution :`CO_(2) + RMgX underset(H_(3)O^(+)) overset("dry ether") to RCOOH + MgXOH`

Discussion

39.	Solid Cl_2O_6 exists as:
Answer» `ClO_2^+. ClO_4^_` COVALENT SPECIES `(ClO_3)_2` None Answer :A

Discussion

40.	Solid CH_(4) is
Answer» MOLECULAR solid Covalent solid lonic solid Non-existent Answer :A

Discussion

41.	Solid Ba(NO_(3))_(2) is gradually dissolved in a 10^(-4)M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form ? (K_(sp) for BaCO_(3)=5.1xx10^(-9))
Answer» `4.1xx10^(-5)M` `8.1xx10^(-8)M` `5.1xx10^(-5)M` `8.1xx10^(-7)M` Solution :`K_(SP)=[BA^(2+)][CO_(3)^(2-)]` `5.1xx10^(-9)=[Ba^(2+)]xx10^(-4)` `[Ba^(2+)]=5.1xx10^(-5)M`.

Discussion

42.	Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0 xx 10^(-4) M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form (K_(sp) for BaCO_(3) = 5.1 xx 10^(-9))
Answer» `4.1 xx 10^(-5) M` `5.1 xx 10^(-5) M` `8.1 xx 10^(-8) M` `8.1 xx 10^(-7) M` SOLUTION :`{:(Na_(2)CO_(3),rarr,2Na^(+),+,CO_(3)^(-2)),(1xx 10^(-4)M,,2 xx 10^(-4)M,,1 xx 10^(-4)M):}` `K_(sp)[BaCO_(3)] = [BA^(+2)][CO_(3)^(-2)]` `5.1 xx10^(-9) = [Ba^(+2)] xx 1 xx 10^(-4)` `[Ba^(+2)] = 5.1 xx 10^(-5) M`.

Discussion

43.	Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0xx10^(-4)MNa_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begain to form? (K_(sp)" for "BaCO_(3)=5.1xx10^(-9))
Answer» `4.1xx10^(-5)`M `5.1xx10^(-5)`M `8.1xx10^(-8)`M `8.1xx10^(-7)`M Answer :B

Discussion

44.	Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0xx10^(-4)M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form ? (K_(sp) " for for " BaCO_(3)=5.1xx10^(-9))
Answer» `5.1xx10^(-5)M` `8.1xx10^(-8)M` `8.1xx10^(-7)M` `4.1xx10^(-5)M` Solution :`underset(1xx10^(-4)M)(Na_(2)CO_(3)) to underset(1xx10^(-4)M)(2NA^(+))+ underset(1xx 10^(-4)M)(CO_(3)^(2-))` `K_(sp(BaCO_(3)))=[Ba^(2+)][CO_(3)^(2-)]` `[Ba^(2+)]=(5.1xx10^(-9))/(1xx10^(-4))=5.1xx10^(-5)M`

Discussion

45.	Solid BaF_2 is added to a solution containing 0.1 mole of sodium oxalate solution (1 litre) until equilibrium is reached.If the Ksp of BaF_2 and BaC_2O_4(s) is 10^(-6) & 10^(-7) respectively.Assume addition of BaF_2 does not cause any change in volume and no hydrolysis of any of the cations or anions. (Given :sqrt116=10.77) If concentration of Ba^(2+) ions in resulting solution at equilibrium is represented as 2.7xx10^(-4), then x is :
Answer» Solution :`BaF_2(s)toBa^(2+)(AQ.)+2F^(-)(aq)` Let 'S' be the solubility of `BaF_2` , but `Ba^(2+)` REACTS with `C_2O_4^(2-)` present in this solution & almost completely convert into `BaC_2O_4` `Ba^(2+)+ C_2O_4^(2-)toBaC_2O_4(s)` Let y mole PER it. of `Ba^(2+)` is left after reaching equilibrium So, `underset(y)(Ba^(2+))+underset(0.1-s)(C_2O_4^(2-))toBaC_2O_4(s) " " Keq=10^(-7)` So, we get the following two equations, `y(0.1-s)=10^(-7) " &" y(2S)^2=10^(-6)=(K_(sp))BaF_2` Solving there two equations, we get, S=0.096 M So , `[C_2O_4^(2-))=0.1-0.096=4xx10^(-3) M` `[F^(-)]=2s=2xx0.096=0.192 M` `[Ba^(2+)]=y=2.7xx10^(-5)M`

Discussion

46.	Solid ammonium carbonate, NH_2COONH_4, dissociates on heating to NH_4 and CO_2:NH_2COONH_4(s) iff 2NH_3(g) + CO_2(g)When pure carbonateis put into a closed container and allowed to come to equilibrium with the gaseous products at a constant temperature, 35^@C , the total pressure is found to be 0.30 atm. Determine K_pfor this reaction at 35^@C.
Answer» SOLUTION :`4.0 XX 10^(-3) atm^3`

Discussion

47.	Solid ammonium carbonate dissociates according to the reactionNH_2COONH_4(s) iff 2NH_3 (g) + CO_2(g)At 298 K, the total pressure of the gases in equilibrium with the solid is 0.116 atm. Calculate K_p.
Answer» SOLUTION :`2.31 XX 10^(-4) atm^3`

Discussion

48.	Solid ammonium carbomate, NH_4CO_2NH_2(s), dissociates into ammonia and carbon dioxide when it evaporates as shown by NH_4CO_2NH_2(s)hArr2NH_3(g)+CO_2(g) At 25^@C, the total pressure of the gases in equilibrium with the solid is 0.116 atm.If 0.1 atm of CO_2 is introduced after equilibrium is reached then :
Answer» Final PRESSURE of `CO_2` will be less than 0.1 atm Final pressure of `CO_2` will be more than 0.1 atm Pressure of `NH_3` will DECREASE due to addition of `CO_2` Pressure of `NH_3` will increase due to addition of `CO_2` SOLUTION :The pressure of `NH_3` will decrease due to addition of `CO_2` (BACKWARD, shifting Le-chatelies's PRINCIPLE).The pressure of `CO_2` will be more than 0.1 atm

Discussion

49.	Solid ammonium carbamate dissociates as follows: NH_(2)COONH_(4)(s)hArr2NH_(3)(g)+CO_(2)(g) At equilibrium, total pressure is found to be 0.3 atm at a given temperature. The value of K_(p) is
Answer» `0.3"ATM"^(3)` `0.108"atm"^(3)` `4.0xx10^(-3)"atm"^(3)` 0.158 atm Answer :C::D

Discussion

50.	Solid aerosol is an example of colloidal system of
Answer» LIQUID DISPERSED in GAS Liquid dispersed in gas SOLID dispersed in gas Solid dispersed in liquid Answer :C

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Solubility curve of Na_(2)SO_(4).10H_(2)O in water with temperature is given as

Solubility curve of a hydrated salt in water with temperature is given. The curve indicates that the solution process is

Solubility curve of Na_(2)SO_(4).10 H_(2)O in water with temperature is given as

Solubilities of three sparingly soluble salts XY(K_(sp)),XY_(2)(K'_(sp)) and X_(2)Y_(3)(K''_(sp)) are equal in water. What will be the correct order of their solubility products

Solubility and thermal stability both increase drown the group for (A.M.= Alkaline metal, A.E.M.=Alkaline earth metal) :

Solubilities of carbonates decrease down the magnesium group due to decrease in :

Solubbility product of PbCl_2 at 298K is 1.0 xx 10^-6. At this temperature solubility of PbCL_2 in mol per litre is :

Sols of metals like Cu, Ag, Au are prepared by

Sols of protein and starch are examples of ........

Sols of gold, silver, platinum and copper are examples of ...............

Solids ice, glucose are examples of ………………….........

Solids have the following characteristics :

Solids for which physical properties like electric resistance or refractive index show different values when measured along different directions are called

Solids can be classified into three types on the basis of their electrical conductivities. Namethree types on the basis of their electrical conductivities.

Solids can be classified into three types on the basis of their electrical conductivities.i) Name three types of solids classified on the basis of electrical conductivities.

Solids are classified into two types. What are they?

_____solids are isotropic in nature.

Solids are classified into two types.Give two examples.

Solidited Cubained from the reverberatory tumaca has bied appearance. This is due to

Solids are characterised by their properties :

Solid phosphorus melts and vapourizes at high temperature. Gaseous phosphorus effuses at a rate that is 0.567 times that of Ne in the same apparatus under the same conditions. How many atoms are in a molecule of gaseous phosphorus.

_____solids are anisotropic in nature.

Solid SO_(2) and solid NH_(3) are examples of

Solid PCl_(5) exists as :

Solid PCl_(5) , exists as

Solid NH_(3) solid CO_(2) are examples of

Solid NaCl is a bad conductor of electricity because

Solid N_2 O_5 exists as NO_2^(oplus) NO_3^(Ө) and hence is called nitronium nitrate. The gas which is acidic in nature is.

Solid methane is

Solid NaCl is bad conductor of electricity because :

Solid KmnO_(4) on heating with H_(2) forms

Solid CO_2 is used as:

Solid CO_(2) is known as dry ice, because

Solid CO_(2) is an example of …………….

Solid CO_2 is an example of:

Solid Cl_(2)O_(6) exists as

Solid carbondioxide and RMgX produces

Solid Cl_2O_6 exists as:

Solid CH_(4) is

Solid Ba(NO_(3))_(2) is gradually dissolved in a 10^(-4)M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form ? (K_(sp) for BaCO_(3)=5.1xx10^(-9))

Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0 xx 10^(-4) M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form (K_(sp) for BaCO_(3) = 5.1 xx 10^(-9))

Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0xx10^(-4)MNa_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begain to form? (K_(sp)" for "BaCO_(3)=5.1xx10^(-9))

Solid Ba(NO_(3))_(2) is gradually dissolved in a 1.0xx10^(-4)M Na_(2)CO_(3) solution. At what concentration of Ba^(2+) will a precipitate begin to form ? (K_(sp) " for for " BaCO_(3)=5.1xx10^(-9))

Solid ammonium carbonate dissociates according to the reactionNH_2COONH_4(s) iff 2NH_3 (g) + CO_2(g)At 298 K, the total pressure of the gases in equilibrium with the solid is 0.116 atm. Calculate K_p.

Solid ammonium carbamate dissociates as follows: NH_(2)COONH_(4)(s)hArr2NH_(3)(g)+CO_(2)(g) At equilibrium, total pressure is found to be 0.3 atm at a given temperature. The value of K_(p) is

Solid aerosol is an example of colloidal system of