94420 + Interview Questions in Chemistry in Class 12

1.	If radium and chlorine combinetofomradiumchloride, the compound would be
Answer» half as radioactive as RADIUM twice as rdioactive as radioactive as radium not radioactive. SOLUTION :Radioactivity REMAINS same in free atom and if it is there in a compound.

Discussion

2.	If (X) turn line water milky , then X may be
Answer» `CO_(2)` `SO_(2)` `NO_(2)` `O_(2)` ANSWER :a,B,

Discussion

3.	If r_(1) is the radius of the first orbit of hydrogen atom, then the radii of second, third and fourth orbitals in terms of r_(1) are
Answer» `r_(1)^(2),r_(1)^(3),r_(1)^(4)` `8r_(1),27r_(1),64r_(1)` `4r_(1),9r_(1),16r_(1)` `2r_(1),6r_(1),8r_(1)` Solution :`r_(N)=0.059n^(2)` (for H-atom) `r_(1)=0.059(1)^(2)` `r_(2)=0.059(2)^(2)=4r_(1)` `r_(3)=0.059(3)^(2)=9r_(1)` `r_(4)=0.059(4)^(2)=16r_(1)` Ratio : `4r_(1):9r_(1),16r_(1)`

Discussion

4.	If X molal solution of a compound is benzene has mole fraction of solute equal to 0.4. Then the value of X is
Answer» 4.2 8.5 3.2 5.1 Answer :B

Discussion

5.	If R_(1) and R_(2)are the resistance of two solution of equal volume, then the conductance of the mixture in the same conductivity cell is:
Answer» `(1)/(2)((1)/(R_1) +(1)/(R_2))` `(1)/(2)((1)/(R_(1)+R_(2)))` `(1)/(sqrtR_(1) R_(2)` none of these Solution : `G_("net") = G_(1) + G_(2)` `K_("net") = (V_(1) + V_(2))`, `K_("net") = (G_(1)G^astxxG_(2)G^astV)/(2V)` , `K_("net") = (1)/(2)((1)/(R_(1)+ (1)/(R_(2))))G^ast = G_("net") G^ast`

Discussion

6.	If X is the specific resistance of the solution and M is the molarity of the solution, the molar conductivity of the solution is given by:-
Answer» `(1000X)/(M)` `(1000)/(MX)` `(1000M)/(X)` `(MX)/(1000)` SOLUTION :Molar CONDUCTIVITY`=(1000)/(MX)`.

Discussion

7.	If R is the radius of octahedral void and r is the radius of the atoms in close packing, then (r )/(R ) is equal to
Answer» 0.414 0.225 2.41 4.44 Solution :

Discussion

8.	If x is the solubility in mol L^(-1)of Ca_(3)(PO_(4))_(2). Its K_(sp)is equal to :
Answer» `X^(5)` `108X^(5)` `6x^(5)` `4X^(4)` Answer :B

Discussion

9.	If r is the radius of an atom in face-centred cubic unit cell of edge length a then
Answer» `R=(a)/(2sqrt(2))` `r=(4)/(sqrt(3))a` `r=2sqrt(2)a` `r=sqrt((3)/(4))a` Answer :A::B

Discussion

10.	If q is the heat added to the system, w is the work done by the system and Delta U is the change in internal energy, then according to first law of thermodynamics :
Answer» <P>`Delta U = q + w` `Delta U = q - w` `Delta U = q + p Delta V` `Delta U = q + Delta H` ANSWER :B

Discussion

11.	If x is the conduction of 1 cm^(3) of the solution and C is the concentration of the solution . The molar conductivity of the solution is given by
Answer» `(1000 C)/(x)` `(1000 x)/(N)` `(C)/(x)` `(x)/(C)` Solution :Molar conductivity ` = (1000 XX "conductance")/("CONCENTRATION")`

Discussion

12.	If P,V,M,Tand R are pressure, volume, molar mass, temperature and gas respectively, then for an ideal gas , the density is given by
Answer» <P>`(RT)/(PM)` `(P)/(RT)` `(M)/(V)` `(PM)/(RT)` SOLUTION :`PV=nRT=(m)/(M ) RT` `:. (m)/(V)=(PM)/(RT)=` DENSITY

Discussion

13.	If x is the amount of adsorbateand m is the amount of adsorbent , which of the following relations is not relatedto adsorption process ?
Answer» <P>x/m=F(P) at CONSTANT T x/m = f(T) at constant P P=f(T) at constant x/m x/m=PT SOLUTION :x/m=PT

Discussion

14.	If [PtCl_6]^(x-)follows the Sidgwick rule of stability, what is the oxidation state of Pt and complex ?
Answer» SOLUTION : `[PtCl_6]^(X-)` following Sidgwick rule of STABILITY ,thus EAN of Pt is to be equal to the atmic number of nearest inert gas 86(Rn). Let the oxidation state of platinumin `[PtCl_6]^(x-)` COMPLEX ion is y `y + 6(-1) = -x (or) y = 6 - x` `86 = 78 - (6-x) + 2xx 6 = 78 - 6 + x + 12 , x = 2` Oxidation state of platinum forming the complex `=6 -x = 6-2 = +4` Oxidation state of the complex = -2

Discussion

15.	If x is the amount of adsorbate and m is the amount of adsorbent, which of the following relations is not related to adsorption process?
Answer» <P>x/m = F(P) at CONSTANT T x/m =f(T) at constant P P = f(T) at constant x/m x/m = PT Answer :D

Discussion

16.	If P_((S)) (solution pressure of metal tendency) gt P_(O) (osmotic pressure of ions in solution tendency) , then
Answer» the electrode gets NEGATIVE charged the electrode gets positively charged Both 'a' and 'b' the electrode remains neutral SOLUTION :Solution PRESSURE of metal tendency also known as de-electronation, where metal has a tendency to pass into the solution in the form of cation leaving electrons (negative charge) on the SURFACE of metal (electrode) .

Discussion

17.	If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process ?
Answer» <P>`X/mpxxT` `x/m=f(p)` at constant T `x/m=f(T)` at constant p `p=f` (T) at constant `((x)/(m))` SOLUTION :`x/m =pxxT` is not a correct relation.

Discussion

18.	If x is amount of adsorbate and m is amount of adsorbent, which of the followingrelations is related to adsorption process ?
Answer» <P>x/m = `p xx T` x/m = f(P) at constant T x/m = f(T) at constant P P = f(T) at constant (x/m) ANSWER :B

Discussion

19.	If P.T would have contained 10 periods, maximum elements in that P.T. would be :-
Answer» 72 190 144 290 Solution :Till `7^(th)` period = 118 element (TOTAL magic no. add`""^(n)`) `8^(th)` period = 59 `9^(th) ` period = 50 next magic no. `10^(th)` period = 72 Total 290

Discussion

20.	If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process?
Answer» <P>`(X)/(m)=F(p)` at CONSTANT T. `(x)/(m)=f(T)` at constant p. `p=f(T)` at constant `((x)/(m))`. `(x)/(m)=p*T` ANSWER :D

Discussion

21.	If pressure increases then its effect on given equlibrium C_((s))+H_(2)O_((g))hArrCO_((g))+H_(2(g)) it is satisfied in
Answer» Forward DIREACTION Backward DIRECTION No EFFECT NONE of these Answer :B

Discussion

22.	If x is amount of adsorbate and ‘m’ is amount of adsorbent, which of the following relations is not related to adsorption process
Answer» <P>`x/m=pxT` `x/m=f(p) at CONSTANT T` `x/m=f(T)` at constant P `P=f(T)` at constant `(x/m)` ANSWER :A

Discussion

23.	If pressure greater than osmotic pressure is applied on the solution separated from the solvent by a semipermeable membrane, the flow of solvent is from …………….to …………………. The process is called………….. .
Answer» SOLUTION :solution, SOLVENT, REVERSE OSMOSIS

Discussion

24.	If X is a member of chalcogen family, the highest stability of X^(-2) is exhibited by
Answer» OXYGEN SELENIUM TELLURIUM SULPHURE ANSWER :A

Discussion

25.	If pressure becomes double at the same absolute temperature on 2L CO_(2), then the volumeof CO_(2) becomes
Answer» <P>2L 4L 25L 1L Solution :`(P_(1))/(P_(2))=(1)/(2) , :' (V_(1))/(V_(2))=(P_(2))/(P_(1))=(2)/(1)` `(2L)/(V_(2))=(2)/(1) , V_(2)1L`

Discussion

26.	If X' is a Anti cancerous drug which of the following conversions will give 'X'
Answer» `[PtCl_(4))]^(2-) OVERSET(NH_(3))to Y overset(NH_(3))to X` `[Pt(NH_(3))_(4)]^(2+) overset(CL^(-))to Y overset(Cl^(-))to X` `[Pt(NH_(3))_(4)]^(2+) overset("Acid")to Y overset("Alkali")to X` `cis [Pt(NH_(3))Cl_(2)]^(2+) overset("Acid")to Y overset("Alkali")to X` Answer :A::B::C::D

Discussion

27.	If pressure becomes double at the same absolute temperature of 2 litre CO_(2), then the volumme of CO_(2) becomes
Answer» 2 litre 4 litre 5 litre 1 litre Answer :B

Discussion

28.	If 'x' dm^3 of N_2 reactwith 10dm^3 of H_2 to form NH_3 under suitable conditions, then
Answer» `H_2` is LIMITING REAGENT `N_2` is limiting reagent Both REACTANTS are limiting REAGENTS `NH_3` is limiting reagent Answer :A

Discussion

29.	If P^(oo) and P are the vapour pressures of the pure solvent and solution and n_(1) and n_2 are the moles of solute and solvent repectively in the soluiton then the correct relation betweenP and p^(@) is
Answer» <P>`P^(@) = P[(n-1)/(n_1 + n_2)]` `P^(@)=P[(n_2)/(n_1+n_2)]` `P= P^(@)[(n_2)/(n_1 +n_2)]` `P= P^(@)[(n_1)/(n_1+n_2)]` Solution :We know ACCORDING to RAOULT .s law, `P = P^(@) . X_("solute") rarr P = P^(@)[ (n_2)/(n_1 =n_2)]`

Discussion

30.	If x denotes the number of valence electrons of the element, then its valency is equal to:
Answer» x-8 Xe 8-x B and C Answer :D

Discussion

31.	If pOH of a solution is 6.0, then its pH will be
Answer» 6 10 8 14 Solution :PH+ POH = 14, pH = 14 - pOH , pH = 14 - 6 = 8.

Discussion

32.	If x and y are total number of electrons which are present in non-axial and axial set off d-orbitals respectively in Ni cation of [Ni(DMG)_(2)], then calculate the value of (2x^(2))/(y)
Answer» ANSWER :36

Discussion

33.	If pK_("In") of an indicator is 10.5, the pH transition range for which it is most suitable is
Answer» `8.5-10.5` `10.5-12.5` `10.0-11.0` `9.5-11.5` SOLUTION :The pH transition range for an indicator `=pK_("in") pm1` `=10.5 PM 1` THEREFORE, suitable range is , 9.5-11.5

Discussion

34.	If (X) decolourises acidfied KMnO_(4) solution , then X may
Answer» `S^(2-)` `SO_(3)^(2-)` `FE^(2+)` `SO_(2)` ANSWER :a,B,c,d

Discussion

35.	If PK_bfor fluoride ion at 25^@C is 10.83. predict the ionisation constant of hydrofluoric acid in water at this temperature.
Answer» `1.74xx10^(-5)` `3.52xx10^(-3)` `6.75xx10^(-4)` `5.38xx10^(-2)` ANSWER :C

Discussion

36.	If work done by an ideal gas in process 1-2 on the given graph is 0.4 kJ then product of pressure and volume at point B (in bar-L) is (Enthalpy of gas in process 3-4 is constant) (1 bar-L = 100 J)
Answer» ANSWER :8

Discussion

37.	If pK_(b) for fluoride ion at 25^(@)C is 10.83, the ionisation constant of hydrofluoric acid in water at this temperature is
Answer» `1.74 xx 10^(-5)` `3.52 xx 10^(-3)` `6.75 xx 10^(-4)` `5.38 xx 10^(-2)` Solution :`HF + H_(2)O overset(K_(a))rarr H_(3)O^(+) + F^(-)` `:. K_(a) = ([H_(3)O^(+)][F^(-)])/([HF][H_(2)O])`...(i) `F^(-) + H_(2)O overset(K_(b))rarr HF + OH^(-)` `:. K_(b) = ([HF][OH^(-)])/([F^(-)][H_(2)O])`...(ii) `:. K_(a) xx K_(b) = [H_(3)O^(+)][OH^(-)] = K_(w) = 10^(-14)` Given, `pK_(b) = 10.83 rArr K_(b) = 1.48 xx 10^(-11)` `:. K_(a) = (10^(-14))/(1.48 xx 10^(-11)) = 6.75 xx 10^(-4)`

Discussion

38.	If we use phenolphthalein as an indicator in a titration of Na_(2)CO_(3) with HCl, the usual result is
Answer» No visible change is occur The indicator REACTS with the acid The indicator reacts with the base Sodium chloride and CARBONIC acid will be formed SOLUTION :The resulting solution is colourless.

Discussion

39.	If pK_(a) of acetic acid and pK_(b) of ammonium hydroxide are 4.76 each. The pH of ammonium acetate is
Answer» 7 Less than 7 More than 7 Zero Solution :pH of a SALT of weak ACID and weak BASE is `pH = 7 + (1)/(2)pK_(a) - (1)/(2)pK_(a)` `pH = 7 + (1)/(2) xx 4.76 - (1)/(2) xx 4.76 = 7`.

Discussion

40.	If we want to study relative arrangement of atoms in a molecule we study
Answer» EMPIRICAL formula Molecular formula Structural formula None of these Solution :N//A

Discussion

41.	If Pk_b for CN^- at 25^@C is 4.7. Find the pH of 0.5 M aqueous NaCN solution,
Answer» 12 10 11.5 11 Answer :C

Discussion

42.	If pi_(1) is the osmotic pressure of solution containing 6 g. of acetic acid per dm^(3) and pi_(2) is that of a solution containing 5.85 g. of NaCl per dm^(3) at the same temperature then
Answer» `pi_(1) lt pi_(2)` `pi_(1) gt pi_(2)` `pi_(1) = pi_(2)` `2pi2pi_(1)=pi_(2)` SOLUTION :Both the SOLUTIONS are one molar but NaCl being an electrolyte will have more, O.P. then acetic acid which is non electrolyte.

Discussion

43.	If we use pyrene (C Cl_(4)) in the Riemer-Tiemann reaction in place of chloroform, the product formed is :
Answer» Salicylaldehyde phenolphthalein Salicylic ACID Cyclohexanol Solution :N//A

Discussion

44.	If we use pyrene (C Cl_(4)) in the Reimer-Tiemann reaction in place of chloroform, the product formed is
Answer» salicylaldehyde phenolphthalein SALICYLIC acid cyclohexanol Answer :C

Discussion

45.	If we use carbon tetrachloride in Reimer Tiemann reaction in place of chloroform, the product formed is
Answer» SALICYLIC ACID Salicylaldehyde Cyclohexanol PHENOLPHTHALEIN ANSWER :A

Discussion

46.	If phi denotes reduction potential, then which is true ?
Answer» `E_("CELL")^(@)= phi_("RIGHT")-phi_("LEFT")` `E_(cell)^(@)=phi_("left")+phi_("right")` `E_(cell)^(@)=phi_("left")-phi_("right")` `E_(cell)^(@)= - (phi_("left")+phi_("right"))` Answer :A

Discussion

47.	If we take two 1 litre flasks, one containing He at STP and other containing CH_(4) at STP [Assume size of CH_(4) is much larger than He ]
Answer» Mean free PATH of He GAS will be more than `CH_(4)` gas Average velocity of He gas will be more than `CH_(4)` gas. Total TRANSLATIONAL kinectic energy of `CH_(4)` will be more than He. Most probable SPEED of He will be more than `CH_(4) (g)` Answer :A::B::D

Discussion

48.	If pH of hydrogen electrode is 10, then what is the potential of it. . .
Answer» 0.59 V 0.00 V `-0.59V` `-0.059V` Solution :`H_((AQ))^(+)+e^(-) to (1)/(2)H_((g))` (reduction) `E=E^(@)-(0.059)/(N)"LOG"(1)/([H^(+)])` `=0.0-(0.059)/(1)pH` `=0-0.059xx10` `=-0.59V`

Discussion

49.	If we use carbon tetrachloride in Reimer- Tiemann reaction in place of chloroform, the product formed is
Answer» Salicylic ACID SALICYLALDEHYDE Cyclohexanol PHENOLPHTHALEIN Answer :A

Discussion

50.	If pH of A, B, C and D are 9.5, 2.5, 3.5 and 5.5 respectively, then strongest acid is
Answer» A C D B SOLUTION :LESS TH PH, more ACIDIC is the solution.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

If radium and chlorine combinetofomradiumchloride, the compound would be

If (X) turn line water milky , then X may be

If r_(1) is the radius of the first orbit of hydrogen atom, then the radii of second, third and fourth orbitals in terms of r_(1) are

If X molal solution of a compound is benzene has mole fraction of solute equal to 0.4. Then the value of X is

If R_(1) and R_(2)are the resistance of two solution of equal volume, then the conductance of the mixture in the same conductivity cell is:

If X is the specific resistance of the solution and M is the molarity of the solution, the molar conductivity of the solution is given by:-

If R is the radius of octahedral void and r is the radius of the atoms in close packing, then (r )/(R ) is equal to

If x is the solubility in mol L^(-1)of Ca_(3)(PO_(4))_(2). Its K_(sp)is equal to :

If r is the radius of an atom in face-centred cubic unit cell of edge length a then

If q is the heat added to the system, w is the work done by the system and Delta U is the change in internal energy, then according to first law of thermodynamics :

If x is the conduction of 1 cm^(3) of the solution and C is the concentration of the solution . The molar conductivity of the solution is given by

If P,V,M,Tand R are pressure, volume, molar mass, temperature and gas respectively, then for an ideal gas , the density is given by

If x is the amount of adsorbateand m is the amount of adsorbent , which of the following relations is not relatedto adsorption process ?

If [PtCl_6]^(x-)follows the Sidgwick rule of stability, what is the oxidation state of Pt and complex ?

If x is the amount of adsorbate and m is the amount of adsorbent, which of the following relations is not related to adsorption process?

If P_((S)) (solution pressure of metal tendency) gt P_(O) (osmotic pressure of ions in solution tendency) , then

If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process ?

If x is amount of adsorbate and m is amount of adsorbent, which of the followingrelations is related to adsorption process ?

If P.T would have contained 10 periods, maximum elements in that P.T. would be :-

If x is amount of adsorbate and m is amount of adsorbent, which of the following relations is not related to adsorption process?

If pressure increases then its effect on given equlibrium C_((s))+H_(2)O_((g))hArrCO_((g))+H_(2(g)) it is satisfied in

If x is amount of adsorbate and ‘m’ is amount of adsorbent, which of the following relations is not related to adsorption process

If pressure greater than osmotic pressure is applied on the solution separated from the solvent by a semipermeable membrane, the flow of solvent is from …………….to …………………. The process is called………….. .

If X is a member of chalcogen family, the highest stability of X^(-2) is exhibited by

If pressure becomes double at the same absolute temperature on 2L CO_(2), then the volumeof CO_(2) becomes

If X' is a Anti cancerous drug which of the following conversions will give 'X'

If pressure becomes double at the same absolute temperature of 2 litre CO_(2), then the volumme of CO_(2) becomes

If 'x' dm^3 of N_2 reactwith 10dm^3 of H_2 to form NH_3 under suitable conditions, then

If P^(oo) and P are the vapour pressures of the pure solvent and solution and n_(1) and n_2 are the moles of solute and solvent repectively in the soluiton then the correct relation betweenP and p^(@) is

If x denotes the number of valence electrons of the element, then its valency is equal to:

If pOH of a solution is 6.0, then its pH will be

If x and y are total number of electrons which are present in non-axial and axial set off d-orbitals respectively in Ni cation of [Ni(DMG)_(2)], then calculate the value of (2x^(2))/(y)

If pK_("In") of an indicator is 10.5, the pH transition range for which it is most suitable is

If (X) decolourises acidfied KMnO_(4) solution , then X may

If PK_bfor fluoride ion at 25^@C is 10.83. predict the ionisation constant of hydrofluoric acid in water at this temperature.

If work done by an ideal gas in process 1-2 on the given graph is 0.4 kJ then product of pressure and volume at point B (in bar-L) is (Enthalpy of gas in process 3-4 is constant) (1 bar-L = 100 J)

If pK_(b) for fluoride ion at 25^(@)C is 10.83, the ionisation constant of hydrofluoric acid in water at this temperature is

If we use phenolphthalein as an indicator in a titration of Na_(2)CO_(3) with HCl, the usual result is

If pK_(a) of acetic acid and pK_(b) of ammonium hydroxide are 4.76 each. The pH of ammonium acetate is

If we want to study relative arrangement of atoms in a molecule we study

If Pk_b for CN^- at 25^@C is 4.7. Find the pH of 0.5 M aqueous NaCN solution,

If pi_(1) is the osmotic pressure of solution containing 6 g. of acetic acid per dm^(3) and pi_(2) is that of a solution containing 5.85 g. of NaCl per dm^(3) at the same temperature then

If we use pyrene (C Cl_(4)) in the Riemer-Tiemann reaction in place of chloroform, the product formed is :

If we use pyrene (C Cl_(4)) in the Reimer-Tiemann reaction in place of chloroform, the product formed is

If we use carbon tetrachloride in Reimer Tiemann reaction in place of chloroform, the product formed is

If phi denotes reduction potential, then which is true ?

If we take two 1 litre flasks, one containing He at STP and other containing CH_(4) at STP [Assume size of CH_(4) is much larger than He ]

If pH of hydrogen electrode is 10, then what is the potential of it. . .

If we use carbon tetrachloride in Reimer- Tiemann reaction in place of chloroform, the product formed is

If pH of A, B, C and D are 9.5, 2.5, 3.5 and 5.5 respectively, then strongest acid is