This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Equivalent conductivity of acetic acid at infinite dilution is 39.7 and for 0.1 M acetic acid the equivalent conductance is "5.2 mho.cm"^(2)."gm.equiv."^(-1). Calculate degree of dissociation, H^(+) ion concentration and dissociation constant of the acid. |
|
Answer» Solution :`ALPHA=(lambda_(C ))/(lambda_(oo))=0.01333=1.33%` `{:(CH_(3)COOHhArrH^(+)+CHCOO^(-)),(C(1-alpha)""Calpha""Calpha):}` `therefore[H^(+)]=Calpha=0.1xx0.0133=0.00133M` `K=(alpha^(2)C)/(1-alpha)=(0.0133^(2)xx0.1)/((1-0.0133))=2.38xx10^(-5)M` |
|
| 2. |
Equivalent conductivity of a weak acid HA at infinite dilution is 390 S cm^(2) eq^(-1).Conductivity of 1 xx 10^(-3) N HA solution is 4.9 xx 10^(-5) S cm^(-1). Calculate the extent of dissociation and dissociation constant of the acid. |
|
Answer» Solution :Equivalent conductivity of `1 XX 10^(-3) N HA` solution `(Lambda_m) = k//"normality"` `Lambda_c = (4.9 xx 10^(-5) xx 1000)/(1 xx 10^(-3)) = 49 S cm^(2) eq^(-1)` Equivalent CONDUCTANCE at infinite dilution `(Lambda_0) = 390 S cm^(2) eq^(-1)` Extent of dissociation = `alpha = (Lambda_c)/(Lambda_0) = 49/390 = 0.126` Dissociation constant of ACID = `C alpha^(2) = 1 xx 10^(-3) (0.126)^(2) = 1.5 xx 10^(-5) mol L^(-1)`. |
|
| 3. |
Equivalent conductivity of a weak acid HA at infinite dilution is390 S cm^(2) eq^(-1).Conductivity of 1xx10^(-3) N HA solution is 4.9xx10^(-5) S cm^(-1).Calculate the extent of dissociation and dissociation constant of the acid. |
|
Answer» Solution :`Lambda_(c) = (4.9 xx 10^(-5) xx 1000)/(1xx10^(-3))=49 S cm^(2) eq^(-1)`. Equivalent CONDUCTANCE at infinite DILUTION `(Lambda_(0))=390 S cm^(2) eq^(-1)`. Extent of dissociation `= alpha = (Lambda_(c))/(Lambda_(0))=(49)/(390)=0.126`. Dissociation CONSTANT of ACID `= C alpha^(2) = 1xx10^(-3) (0.126)^(2)=1.5 x 10^(-5) "mol" L^(-1)`. |
|
| 4. |
Equivalent conductivity at infinite dilution for sodium potassium oxalate, (COO^(-))_(2)Na^(+)K^(+), will be (given, molar conductivities of oxalate, K^(+) and Na^(+) ions at infinite diluton are 148.2,50.1,73.5" S "cm^(2)mol^(-1) respectively). |
|
Answer» `271.8" S "cm^(2)eq^(-1)` `=(50.1+73.5+148.2)" S "cm^(2)MOL^(-1)` `=271.8" S "cm^(2)mol^(-1)` `wedge_(eq)^(@)=(wedge_(m)^(@))/("TOTAL chrge on cations or ANIONS (n factor)")` `=(271.8)/(2)=135.9" S "cm^(2)eq^(-1)`. |
|
| 5. |
Equivalent conductivity at infinite dilution for sodium potassium oxalate (COO^(-))_(2)Na^(+)K^(+) will be [given, molar conductivities of oxalate, K^+ and Na^(+) ions at infinite dilution are 148.2, 50.1, 73.5 S cm^(2)mol^(-1), respectively] |
|
Answer» `271.8cm^(2)eq^(-1)` `lamda_(M)^(oo)=(148.2+50.1+73.5)S" "cm^(2)mol^(-1)` `lamda_(M)^(oo)=271.8S" "cm^(2)mol^(-1)` `thereforelamda_(Eq)^(oo)=(271.8)/(2)=135.9S" "cm^(2)eq^(-1)(lamda_(eq)^(oo)=(lamda_(M)^(oo))/("N. factor"))` |
|
| 6. |
Equivalent conductivity at infinite dilution for sodium- potassium oxalate ((COO^(-))_2 Na^(+)K^(+)) will be [ Given molar conductivities of oxalate, K^(+) and Na^(+) ions at infinite dilution are 148.2, 50.1, 73.5 S cm^(2) mol^(-2) respecitively ' |
|
Answer» `271.8 S cm^(2) eq^(-1)` `lambda^(m)^(oo) =(148.2 + 50.1+73.5)S cm^(2) mol^(-1)` `lambda_(m)^(oo) =271. 8Scm^(2) mol^(-1)` `therefore lambda_(eq)^(oo) = (271.8)/(2) = 135.8 S cm^(2) eq^(-1)((lambda_(eq)^(oo) = (lambda_m)^(oo))/("N. factor"))` |
|
| 7. |
Equivalent conductivity at infinite dilutionfor sodium-potassium oxalate ((COO^(-))_2 Na^(+) K^(+)) will be [given, molar conductivities of oxalate, K^(+) and Na^(+) ions at infinite dilution are 148.2, 50.1, 73.5S cm^(2) mol^(-2), respectively ] . |
|
Answer» `271.8 S cm^2 EQ^(-1)` |
|
| 8. |
Equivalent conductivity and infinite dilution of NaCl at C concentration is lamda_(C) and lamda_(oo) respectively. So, for lamda_(C) and lamda_(oo), which relation is true ? (where, constant B is solid). |
|
Answer» `lamda_(C)=lamda_(OO)(B)SQRT(c)` |
|
| 9. |
Equivalentconductance of BaCI_(2), H_(2)SO_(4) and HCIare x_(1)x_(2) and x_(3) S cm^(2) "equiv"^(-1)atinfinitedilution if specific conductance of saturated BaSO_(4)solutionis of y S cm d^(-1) then k_("SP") of BaSO_(4) is |
|
Answer» `(10^(3)y)/(2(x_(1)+x_(2)-2x_(3))` `wedge_(BaSO_(4))^(@)=(1000xx"specific conductance")/("solubility" ("in SATURATED solution" ))` `X_(1)+x_(2)-2x_(3)=(1000Y)/("solubility")` `therefore`solubility `(BaSO_(4))=(1000y)/(x_(1)+x_(2)-2x_(3))N=(1000y)/(2(x_(1)+x_(2)-2x_(3))M` `K_(SP)(BaSO_(4))=[Ba^(2+)][SO_(4)^(2-)]M^(2)=(10^(6)y^(2))/(4(x_(1)+x_(2)-2_(3))^(2)` |
|
| 11. |
Equivalent conductance of saturated BaSO_4 is 400 ohm^(-1) cm^(2) "equiv"^(-1) and specific conductance is8 xx 10^(-5) ohm^(-1), cm^(-1) . Hence K_(sp) of BaSO_4is |
|
Answer» `4 XX 10^(-8) M^(2) ` ` S = M = (N)/(2) = (2 xx 10^(-4))/(2) = 10^(-4) M , K_(sp) = S^(2) = (10^(-4))^(2) = 10^(-5)` |
|
| 12. |
Equivalent conductance of 0.01 N Na_2SO_4 solution is 112.4ohm^(-1)cm^2eq^(-1).The equivalent conductance at infinite dilution is 129.9ohm^(-1)cm^2eq^(-1). What is the degree of dissociationin 0.01 N Na_2SO_4 solution |
| Answer» | |
| 13. |
Equivalent conductance for weak electrolyte on dilution ________. |
| Answer» SOLUTION :INCREASES RAPIDLY | |
| 14. |
Equivalent conductance for week electrolyte on dilution ________. |
| Answer» SOLUTION :INCREASES RAPIDLY | |
| 15. |
Equivalent conductance for strong electrolyte on dilution decreases rapidly. |
| Answer» SOLUTION :INCREASES SLOWLY. | |
| 16. |
Equivalent conductance for strong electrolyte on dilution decreases rapidly. Is it true or false? |
| Answer» SOLUTION :INCREASES SLOWLY. | |
| 17. |
Equinormal solution of two weak acids, HA(pK_(a) =3) and HB(pK_(a) =5) are each placed in contact with standard hydrogen electrode at 25^(@)C. When a cell is constructed by interconnecting them thorugh a salt bridge find the e.m.f. of the cell. |
|
Answer» `Pt H_(2(1atm)) |HA_(2)||HA_(I) |H_(2(1atm)) Pt` At `L.H.S.: E_(H//H^(+)) = E_(OP_(H//H^(+)))^(@) +(0.059)/(1) log_(10) [H^(+)]_(2)` `:' -log H^(+) =pH :. E_(H//H^(+)) = E_(OP_(H//H^(+)))^(@) -0.059(pH)_(2)` At `R.H.S. : E_(H^(+)//H) =E_(RP_(H^(+)//H))^(@) +(0.059)/(1)log[H^(+)]_(1)` `:. E_(H^(+)//H) =E_(RP_(H^(+)//H))^(@) -0.059(pH)_(1)` For Acid `HA_(1) HA_(1) hArr H^(+) +A_(1)^(-)` `[H^(+)] = C. alpha = sqrt(K_(a)/C)` `:. (pH)_(1) = (1)/(2) pK_(a_(1)) -(1)/(2) log_(10)C` SIMILARLY, `(pH)_(2) = (1)/(2) pK_(a_(1)) -(1)/(2) log_(10)C` `( :' C` are same) `E_(cell) = E_(OP_(H^(+)//H))^(@) +E_(RP_(H^(+)//H))^(@)` For II for I `= 0.059 [(1)/(2) pK_(a_(2)) -(1)/(2) pK_(a_(1))] =(0.059)/(2) [5-3]` `=+0.059` |
|
| 18. |
Equivalent conductance for strong electrolyte on dilution _______. |
| Answer» SOLUTION :INCREASES SLOWLY | |
| 19. |
Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH. |
|
Answer» `MgCl_(2)` |
|
| 20. |
Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest pH value- |
|
Answer» LICL `[M(H_2O)_x]^(n^+) A hydrated metal cation in which the cation possesses high charge density has high ability to donate proton. In the GIVEN salts, the charge densities of the cations follow the order `Ba^(2+) |
|
| 21. |
Equimolar solutions of the following were prepared in water separately. Which of the solutions will have the highest pH- |
|
Answer» `SnCl_2` |
|
| 22. |
Equimolar solutions of NaCl and BaCl_(2) are prepared . If the freezing point of NaCl is - 2^(@)C, the freezing point of BaCl_(2) is expected to be |
|
Answer» `-2^(@)C` For NACL, `DeltaT_(f)=2, i=2` `2=2xxK_(f)xxm` For `BaCl_(2), DeltaT_(f)=?, i=3` `DeltaT_(f)=3xxK_(f)xxm` Since `K_(f)` and m are same for equimolar solutions, `(DeltaT_(f))/(2)=3/4` or `DeltaT_(f)=3` `:.` Freezing POINT of `BaCl_(2)` solution `=0-3=-3^(@)C` |
|
| 23. |
Equimolar solutions of electrolytes with different number of ion in the same solvent have |
|
Answer» Same BOILING POINT but DIFFERENT FREEZING point |
|
| 24. |
Equimolar solutions of electrolytes in the same solvent have |
|
Answer» Same BOILING point but DIFFERENT freezing point |
|
| 25. |
Equimolar solutions (A) of benzonic acid in bvenzene and (B) of benzoic acid in water are taken How are the Van't Hoff facdtors of the solutions related ? |
Answer» Solution :In benzene solvet, benzoic acid exists as dimar while in water, it dissociates into IONS. ![]() `"Van't Hoff FACTOR (i)"=("Normal molar mass")/("Observed molar mass")` For solution A in benzene, `ilt1` and for solution B in water `igt1`. Thus, the Van't Hoff factor for solution A is less then the Van't Hoff factor for solution B. |
|
| 26. |
Equimolar mixture of two gases A_(2) and B_(2) is taken in a rigid vessel at temperature 300 K. The gases reacts according to given equations : A_(2)(g)hArr2 A (g)K_(P1)=? B_(2)(g)hArr2 B (g)K_(P2)=? A_(2)(g)+B_(2)(g)hArr2 AB (g)K_(P3)=2 If the initial pressure in the container was 2 atm and final pressure developed at equilibrium is 2.75 atm. in which equilibrium partial pressure of gas AB was 0.5 atm, calculate the ratio of (K_(P2))/(K_(P1)) [Given : Degree of dissociation of B_(2) is greater than A_(2)]. |
|
Answer» 8 |
|
| 27. |
Equimolar concentrations of H_(2)and I_(2) are heated to equilibrium in a 2 litre falsek. At equlibrium, the forward and the backward rate constants are found to be equal. What percentage of initial concentration of H_(2) has reacted at equilibrium |
| Answer» ANSWER :A | |
| 28. |
Equimolar mixture of alpha-D(+)-glucose has specific ([alpha]_(D)) is |
|
Answer» `-92.4^@` |
|
| 29. |
Equimolar mixture of hydrogen and carbonmonoxide is called as……………………… |
|
Answer» |
|
| 30. |
Equimolar aqueous solutions of NaCI and BACI_(2) are prepared. If the freezing point of NaCI is -2^(@)C, the freezing point of BaCI_(2) solution is expected to be: |
|
Answer» `-2^(@)C` `NaCItoNa_((aq))^(+)+CI_((aq))^(-)` ` BaCI_(2)toBa_((aq))^(2+)+2CI_((aq))^(-)` `"If "alph a"for " NaCI is -2^(@)C` `"Then " ALPHA "for" BaCI_(2) "is EXPECTED tobe" =-3^(@)C.` |
|
| 31. |
Equimolal solutions will have the same elevation in boiling point, provided they do not show: |
|
Answer» Electrolysis |
|
| 32. |
Equimolal solutions will have the same boiling point, provided they do not show |
|
Answer» electrolysis `Delta T=iK_(b) xx` `"molality" (iK_(b) xx "molality")` |
|
| 33. |
Equimolal solutions of NaCl and BaCl_(2) are prepared in water. Freezing point of NaCl is foundto be -2^(@)C. What freezing point do you expect for BaCl_(2) solution? |
|
Answer» Solution :`"i for NaCl = 2, i for BaCl"_(2)=3`. HENCE, `((DeltaT_(F))_("NACl"))/((DeltaT_(f))_("BaCl"_(2)))=(2)/(3)or(DeltaT_(f))_("BaCl"_(2))=(3)/(2)xx2=3^(@)" so that T"_(f)" for BACl"_(2)=-3^(@)C`. |
|
| 34. |
Equimolal solutions of A and B show depression in freezing point in the ratio 2 : 1. A remains in its normal state in solutions. B will be in solution: |
|
Answer» Normal |
|
| 35. |
Equilibrium constants are given (in atm) for the following reactions at 0°C : SrCl_(2). 6H_(2)O(s)hArrSrCl_(2).2H_(2)O(s) + 4H_(2)O(g) K_(p) = 5 x× 10^(-12) Na_(2)HPO_(4).12H_(2)O(s)hArrNa_(2)HPO_(4). 7H_(2)O (s)+ 5H_(2)O(g)K_(p) = 2.43 x× 10^(-13) Na_(2)SO_(4).10H_(2)O(s)hArrNa_(2)SO_(4)(s) + 10 H_(2)O(g) K_(p) = 1.024 x× 10^(-27) The vapour pressure of water at 0° C is 4.56 torr. At what relative humidities will Na_(2)SO_(4) be deliquescent (i.e. absorb moisture) when exposed to the air at 0°C? |
|
Answer» above 33.33 % |
|
| 36. |
Equilibrium constants are given (in atm) for the following reactions at 0°C : SrCl_(2). 6H_(2)O(s)hArrSrCl_(2).2H_(2)O(s) + 4H_(2)O(g) K_(p) = 5 x× 10^(-12) Na_(2)HPO_(4).12H_(2)O(s)hArrNa_(2)HPO_(4). 7H_(2)O (s)+ 5H_(2)O(g)K_(p) = 2.43 x× 10^(-13) Na_(2)SO_(4).10H_(2)O(s)hArrNa_(2)SO_(4)(s) + 10 H_(2)O(g) K_(p) = 1.024 x× 10^(-27) The vapour pressure of water at 0° C is 4.56 torr. At what relative humidities will Na_(2)SO_(4). 10 H_(2)O be efflorescent (release moisture) when exposed to air at 0°C ? |
|
Answer» above 33.33 % |
|
| 37. |
Equilibrium constants are given (in atm) for the following reactions at 0°C : SrCl_(2). 6H_(2)O(s)hArrSrCl_(2).2H_(2)O(s) + 4H_(2)O(g) K_(p) = 5 x× 10^(-12) Na_(2)HPO_(4).12H_(2)O(s)hArrNa_(2)HPO_(4). 7H_(2)O (s)+ 5H_(2)O(g)K_(p) = 2.43 x× 10^(-13) Na_(2)SO_(4).10H_(2)O(s)hArrNa_(2)SO_(4)(s) + 10 H_(2)O(g) K_(p) = 1.024 x× 10^(-27) The vapour pressure of water at 0° C is 4.56 torr. Which is the most effective drying agent at 0°C |
|
Answer» `SrCl_(2).2H_(2)O` |
|
| 38. |
The equilibrium constant for the reaction is 10 at 300K. What will be the value of triangleG^@ ? |
|
Answer» Standard free energy CHANGE`traingleG^@` |
|
| 39. |
Equilibrium constant of a reaction is related to |
|
Answer» Standard FREE energy CHANGE `DELTAG^(@)` |
|
| 40. |
Equilibrium constant K_(p) for the reaction: CaCO_(3)(s) |
|
Answer» `n_(CO_(2)) =(PV)/(RT) = (0.82 xx 20)/(0.082 xx 1000) = 0.2` mole Mole of `CaCO_(3)` dissociated `=n_(CO_(2)) =0.2` AMOUNT dissociated `=0.2 xx 100 = 20g` |
|
| 41. |
Equilibrium constant is related to E^(@) but not to E_(cell). Explain why? |
|
Answer» Solution :When equilibrium is reached in the cell REACTION, BECOMES equal to ZERO. However `E_(cell)^(@)` is a CONSTANT quantitiy. Hence, applying Nernst equation to the cell reaction, e.g., to the reaction: `Zn+Cu^(2+)hArrZn^(2+)+Cu`, `E_(cell)=E_(cell)^(@)-(RT)/(nF)"LN"([Zn^(2+)])/((Cu^(2+)))=E_(cell)^(@)-(RT)/(nF)"ln "K_(c)`, At equilibrium `E_(cell)=0`. hence, `E_(cell)^(@)=(RT)/(nF)"ln "K_(c)`. |
|
| 42. |
Equilibrium constant for the following reactions at 1200 K are given : 2H_(2)O_((g))iff2H_(2(g))+O_(2(g)),K_(1)=6.4xx10^(-8) 2CO_(2(g))iff2CO_((g))+O_(2(g)),K_(2)=1.6xx10^(-6) The equilibrium constant for the reaction H_(2(g))+CO_(2(g))iffCO_((g))+H_(2)O_((g)) at 1200 K will be |
|
Answer» Solution :Given : `2H_(2)O_((G))iff2H_(2(g))+O_(2(g))` `K_(1)=6.4xx10^(-8)""...(i)` `2CO_(2(g))iff2CO_((g))+O_(2(g))` `K_(2)=1.6xx10^(-6)""...(ii)` Required equation is, `H_(2(g))+CO_(2(g))iffCO_((g))+H_(2)O_((g)),K=?` By reversing equation (i) and by multiplying it with 1/2, we get `H_(2(g))+(1)/(2)O_(2(g))iffH_(2)O_((g)),K._(1)=sqrt((1)/(6.4xx10^(-8)))""...(iii)` And by multiplying equation (ii) with 1/2, we get `H_(2(g))+CO_(2(g))iffCO_((g))+H_(2)O_((g)),K.=K._(1)xxK._(2)` `K.=sqrt((1.6xx10^(-6))/(6.4xx10^(-8)))=sqrt(25)=5` |
|
| 43. |
Equilibrium constant for the following reactions have been determined at 823K. CaO(s)+H_(2)(g)hArrCO(s)+H_(2)O(g) K_(1)=60 CaO(s)+CO(g)hArrCO(S)+CO_(2)(g) K_(2)=400 Using this information, calculate, equilibrium constant (at the same temperature) for :- CO_(2)(g)+H_(2)(g)hArrCO(s)+H_(2)O(g)K_(3)=? CO(g)+H_(2)O(g)hArrCO_(2)(g)+H_(2)(g)K_(4)=? |
|
Answer» `K_(3)=0.15,K_(4)=6.66` `K_(4)=(K_(2))/(K_(1))` |
|
| 44. |
Equilibrium constant for the given reaction is K=10^(20) at temperature 300 K A(s)+2B(aq.)hArr2C(s)+D(aq.) K=10^20 The equilibrium conc. of B starting with mixture of 1 mole of A and1//3 mole/litre of B at 300 K is |
|
Answer» `~4XX10^(-11)` `x~~1//3` `10^(20)=(1/3)/[B]^2 " " implies 10^20=(1/3)/a^2" " implies a^2=1/(3xx10^20)=10^(-20)/3` `a=10^(-10)/sqrt3~~4xx10^(-11)M` |
|
| 45. |
Equilibrium constant for reaction NH_(4)OH(aq)+H^(+)(aq)hArr NH_(4)^(+)(aq)+H_(2)O(l) 1.8xx19^(9). Hence equilibrium constant for ionization NH_(3)+H_(2)OhArr NH_(4)^(+)(aq)+OH^(-)(aq) is x xx 10^(-6). The value of 'x' is |
|
Answer» |
|
| 46. |
Equilibrium concentrations of A and B involved in following equilibrium are 0.01 M and 0.02 M respectively: [A(g) |
|
Answer» `6.67` X `10^-2` M |
|
| 47. |
Equilibrium concentration of HI,I_(2) and H_(2) is 0.7, 0.1 and 0.1 M respectively. The equlibrium constant for the reaction I_(2)+H_(2)hArr2HIis |
|
Answer» 36 |
|
| 48. |
Equilibrium concentration of HI, I_(2) and H_(2) is 0.7, 0.1 and 0.1 moles/litre. Calculate the equilibrium constant for the reaction : I_(2(g))+H_(2(g))hArr2HI_((g))- |
|
Answer» 0.36 |
|
| 49. |
Equilibrium concentration of HI, I_2 and H_2 are 0.7, 0.1 and 0.1 M respectively.The equilibrium constant forthe reaction, I_2 + H_2 ⇌ 2HI is : |
|
Answer» 0.36 |
|
| 50. |
Equations have been applied to the above problems for hydrogen atom. Can these equations be applied to calculate r,E, v, etcfor He^(+) and Li^(2+) ions? |
| Answer» Solution :As the Bohr theory is applicable to a ONE-electron system, the said equations can be APPLIED to `He^(+) and LI^(2+)` ions as these species have only one electron each. The value of Z will be taken as 2 and 3 for `He^(+) and Li^(2+)` respectively. | |