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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Equimolar solution of the following were prepared in water separately. Which one of the solutions will record the highest `pH`?A. `BaCl_(2)`B. `MgCl_(2)`C. `CaCl_(2)`D. `SrCl_(2)` |
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Answer» Correct Answer - A The `pH` of salt `BaCl_(2)=7`, whereas `SrCl_(2)` and `CaCl_(2)=7` and `MgCl_(2)lt7`. |
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| 52. |
`100 mL` of `0.02M` benzoic acid `(pK_(a)=4.2)` is titrated using `0.02 M NaOH`. `pH` values after `50 mL` and `100 mL` of `NaOH` have been added areA. `3.50,7`B. `4.2,7`C. `4.2,8.1`D. `4.2,8.25` |
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Answer» Correct Answer - C `underset(t_(eq))underset(t=0)(C_(6)H_(5)COOH)+underset(1)underset(2)(OH^(-)) rarr underset(-)underset(1)(C_(6)H_(5)COO^(-))+ underset(1)underset()(H_(2)O)` `pH=pK_(a)=4.2` `underset(t_(eq))underset(t=0)(C_(6)H_(5)COOH)+underset(-)underset(2)(OH^(-)) rarr underset(-)underset(2)(C_(6)H_(5)COO^(-))+ underset(2)underset()(H_(2)O)` `[C_(6)H_(5)COO^(-)]=(2)/(200)=0.01 M` `:. pH=7+pK_(a)+(1)/(2)logC` `=7+(4.2)/(2)+(1)/(2)log(0.01)=8.1` |
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| 53. |
1 M benzoic acid `(pK_a=4.20)` and 1 M `C_6H_5COONa` solutions are given separately What is the volume of benzoic acid required to prepare a 300 ml buffer solution of pH =4.5 ? [log 2 =0.3]A. `200 ml`B. `150ml`C. `100ml`D. `50ml` |
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Answer» Correct Answer - C `pH=pK_(a)+log``(["Salt"])/([Acid])` `:. 4.5=4.2+log``(["Salt"])/([Acid])=log``(["Salt"])/([Acid])=0.3` (since `log 2=0.3`) `:. (["Salt"])/([Acid])=2` Let `Vml 1 M C_(6)H_(5)COOH` solution and `(300-V) 1 M C_(6)H_(5)COONa` solution be mixed together `[Acid]=(Vxx1)/(1000)xx(1000)/(300)` , `[Salt]=(300-V)/(1000)xx(1000)/(300)` `[Acid]=(V)/(300)`, `["Salt"]=(300-V)/(300)` `:. (300-V//300)/(V//300)=2=300-V=2V :. V=100 ml` |
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| 54. |
At `298 K` a`0.01 M CH_(3)COOH` solution is `1.34%` ionized. The ionization constant `K_(a)` for acetic acid will beA. `1.82xx10^(-5)`B. `18.2xx10^(-5)`C. `0.182xx10^(-5)`D. None of these |
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Answer» Correct Answer - A `K=c alpha^(2)=0.1xx((1.34)/(100))^(2)=1.8xx10^(-5)` |
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| 55. |
From separate solutions of sodium salts, `NaW`, `NaX`, `NaY` and `NaZ` have `pH 7.0`, `9.0`, `10.0` and `11.0` respectively. When each solution was `0.1 M`, the strongest acid is:A. `HW`B. `HX`C. `HY`D. `HZ` |
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Answer» Correct Answer - A The salt hydrolysis in each case occurs except NaW because its `pH=7`. Thus `HW` is strongest acid. |
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| 56. |
Which of the following can act both as Bronsted acid and as Bronsted base?A. `C1^(-)`B. `HCO_(3)^(-)`C. `H_(3)O^(+)`D. `OH^(-)` |
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Answer» Correct Answer - B Those substances that accept protons are called Bronsted base and those that donate that protons are called Bronsted acid. `HCO_(3)^(-)+H^(+)hArrH_(2)CO_(3)` Bronsted base `HCO_(3)^(-)hArrH^(+)+CO_(3)^(--)` Bronsted acid |
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| 57. |
Which equilibrium can be described as an acid- base reaction using the Lewis acid-base defination but not using the Bronsted-Lowry definitionA. `2NH_(3)+H_(2)SO_(4)hArr2NH_(4)^(+)+SO_(4)^(2-)`B. `NH_(3)+CH_(3)COOHhArrNH_(4)^(+)CH_(3)COO^(-)`C. `H_(2)O+CH_(3)COOHhArrH_(3)O^(+)+CH_(3)COO^(-)`D. `[Cu(H_(2)O)_(4)]^(2+)+4NH_(3)hArr[Cu(NH_(3))_(4)]^(2+)+4H_(2)O` |
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Answer» Correct Answer - D It involves gain and loss of electron pair (Lewis concept). |
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| 58. |
According to Bronsted principle, an aqueous solution of `HNO_(3)` will containA. `NO_(2)^(-)`B. `NO_(3)^(-)`C. `NO_(2)^(+)`D. `NO^(+)` |
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Answer» Correct Answer - B According to Bronsted principle `HNO_(3)` is acid, it gives `H^(+)` in aqueous solution and forms `NO_(3)^(-)`. |
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| 59. |
Which of the following strongest acid in the following?A. `HCIO_(3)`B. `HCIO_(4)`C. `H_(2)SO_(3)`D. `H_(2)SO_(4)` |
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Answer» Correct Answer - B Acidic order : `overset(+7)(HClO_(4))gtoverset(+5)(HClO_(3))gtoverset(+3)(HClO_(2))gtoverset(+1)(HClO)`. The higher is the oxidation number of central non-metal in oxo acids, the more stronger is the acid. Also `HClO_(4)` is stronger acid than `H_(2)SO_(4)`. |
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| 60. |
If `pH` of `A`, `B`,`C` and `D` are `9.5`, `2.5`, `3.5` and `5.5` respectively, then strongest acid isA. `A`B. `C`C. `D`D. `B` |
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Answer» Correct Answer - D Less the `pH`, more acidic is the solution. |
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| 61. |
Assertion : Aqueoous solutions of all strong acids contain only the same acid, the hydronium ion. Reason : Hydronium ion is the strongest acid that can exist in any significant concentration in dilute aqueous solution.A. If both assertion and reason are true and the reason is the correct explantion of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - A Due to very strong extent of hydration of `H^(+)ion`. |
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| 62. |
Calculate `pH` of `0.002 N NH_(4)OH` having `2%` dissociationA. `7.6`B. `8.6`C. `9.6`D. `10.6` |
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Answer» Correct Answer - C `NH_(4)OH` is a weak base and partially dissociated `{:(,NH_(4)OH,hArr,NH_(4)^(+),+,OH^(-)),("Concentration",1,,0,,0),("before dissociation",,,,,),("Concentration",1-alpha,,alpha,,alpha),("after dissociation",,,,,):}` `:. [OH^(-)]=C alpha=2xx10^(-3)xx(2)/(100)=4xx10^(-5)M` `pOH= -log[OH^(-)]` `= -log4xx10-5=4.4` `pH=14-4.4=9.6` |
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| 63. |
Which among the following is strongest acid?A. `H(ClO)O_(2)`B. `H(ClO)O_(3)`C. `H(ClO)O`D. `H(ClO)` |
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Answer» Correct Answer - B For oxoacids of the same element, the acidic strength increases with increases in the oxidation number of that element. `overset(+1)(HClO) lt overset(+3)(HClO_(2)) lt overset(+5)(HClO_(3)) lt overset(+7)(HClO_(4))` |
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| 64. |
`pH` of water is `7`. When a substance `Y` is dissolved in water, the `pH` becomes `13`. The substance `Y` is a salt ofA. Strong acid and strong baseB. Weak acid and weak baseC. Strong acid and weak baseD. Weak acid and strong base |
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Answer» Correct Answer - D If we mixed any substance into the solution, them the value of `pH` is increased these sustances are salts of weak acid and strong base. |
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| 65. |
Assertion : The `pH` of pure water is less than `7` at `60^(@)C`. Reason : As the temperature increases, pure water becomes slightly acidic.A. If both assertion and reason are true and the reason is the correct explantion of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - C The scale of `pH` (`0` to `14` at `25^(@)C`) change to (`0` to `lt14`) as the temperature rises because `K_(w)` of water increases with temperature. Note that `[H^(+)] =[OH^(-)]` and thus water remains neutral. |
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| 66. |
To make a solution of `pH=12`, the amount of `NaOH` dissolved in one litre of the solution should beA. `0.1g`B. `0.2g`C. `0.4g`D. `1.2g` |
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Answer» Correct Answer - C `pH=12 means [H^(+)]=10^(-12)` or `[OH^(-)]=10^(-2) M` or `[NaOH] =10^(-2) M (:pOH=2)` `=(1)/(100)xx40gL^(-1)=0.4GL^(-1)` |
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| 67. |
Which of the following aqueous solution will have a `pH` less than `7.0 ?A. `KNO_(3)`B. `NaOH`C. `FeCl_(3)`D. `NaCN` |
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Answer» Correct Answer - C `Fe^(3+)` ions are hydrolysed to develop acidic nature. |
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| 68. |
`pH` value of pure water at `0^(@)C` will be?A. Greater than `7`B. Less than `7`C. `7`D. All of these |
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Answer» Correct Answer - A At `15^(@)C, K_(w)=10^(-14)`. So at temperature below `25^(@)C K_(w)lt10^(-14)` `:. pHgt7` (for neutal solution or pure water) |
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| 69. |
At certain temperature `K_(w)` for water `4xx10^(-14)` which of the following is incorrect for pure water at the given temperature? `log 2=0.3`A. `pH=6.7` and water is acidicB. `pH=6.7` and water is neutralC. `pOH=6.7` and water is neutralD. `pH+pOH=13.4` |
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Answer» Correct Answer - A `[H^(+)][OH^(-)]=K_(w)=4xx10^(-14)` In pure water `[H^(+)]=[OH^(-)]` `:. [H^(+)]=2xx10^(-7)` or `pH=7-log2=7-0.3=6.7=pOH` pure water is neutral. |
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| 70. |
If `K_(h)` (hydrolysis constant) for anilinium ion is `2.4xx10^(-5) M`, then `K_(b)` for aniline will beA. `4.1xx10^(10)`B. `4.1xx10^(-10)`C. `2.4xx10^(9)`D. `2.4xx10^(-19)` |
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Answer» Correct Answer - B `K_(h)` for anilinium ion `=2.4xx10^(-5) M` `K_(h)=(K_(w))/(K_(b))` `K_(b)=(10^(-14))/(2.4xx10^(-5))=4.1xx10^(-10)` |
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| 71. |
If `K_(sp)` for `HgSO_(4)` is `6.4xx10^(-5)`, then solubility of this substance in mole per `m^(3)` isA. `8xx10^(-3)`B. `6.4xx10^(-5)`C. `8xx10^(-6)`D. None of these |
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Answer» Correct Answer - A `K_(sp)=s^(2)` `s=sqrt(K_(sp))=sqrt(6.4xx10^(-5))` `s=8xx10^(-3)` `s=8mol//m^(3)` |
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| 72. |
The dissociation constants of two acids `HA_(1)` and `HA_(2)` are `3.0xx10^(-4)` and `1.8xx10^(-5)` respectively. The relative strengths of the acids will be approximatelyA. `1 : 4`B. `4 : 1`C. `1 : 16`D. `16 : 1` |
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Answer» Correct Answer - B Relative strength `=sqrt((K_(a_(1)))/(K_(a_(2))))=sqrt((3xx10^(-4))/(1.8xx10^(-5))) implies 4 : 1` |
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| 73. |
If `pK_(b)` for fluoride ion at `25^(@)C` is `10.83`, the ionization constant of hydrofluroic acid in water at this temparature isA. `1.74xx10^(-5)`B. `3.52xx10^(-3)`C. `6.95xx10^(-4)`D. `5.38xx10^(-2)` |
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Answer» Correct Answer - C `{:(HF+H_(2)O,hArr,F^(+)+H_(3)O^(+)),(K_(a)xxK_(b)=k_(w),,pK_(a)+pK_(b)=pK_(w)):}` `pK_(a)=14-10.83 implies pK_(a)=3.17` `K_(a)=6.75xx10^(-4)` |
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| 74. |
The solubility of `CaF_(2) (K_(sp)=3.4xx10^(-11))` in `0.1 M` solution of `NaF` would beA. `3.4xx10^(-12) M`B. `3.4xx10^(-10) M`C. `3.4xx10^(-9) M`D. `3.4xx10^(-13) M` |
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Answer» Correct Answer - C `underset(0.1)(NaF) rarr underset(0.1)(Na^(+))+underset(0.1)(F^(-))` `CaF_(2) rarr Ca^(2+)+underset((2x+0.1)=0.1)(2F^(-))` `K_(sp)=x(0.1)^(2)=3.4xx10^(-11)x=3.4xx10^(-9)` |
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| 75. |
The hydrolysis constant for `ZnCl_(2)` will be where `K_(b)` is effective dissociation constant of base `Zn^(++)`A. `K_(h)=(K_(w))/(K_(b))`B. `K_(h)=(K_(w)^(2))/(K_(b))`C. `K_(h)=(K_(w)^(2))/(K_(b)^(2))`D. `K_(h)=(K_(b))/(K_(w)^(2))` |
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Answer» Correct Answer - B `Zn^(++)+2H_(2)OhArrZn(OH)_(2)+2H^(+)` `:. K_(h)=([Zn(OH)_(2)][H^(+)]^(2))/([Zn^(++)])` (`1`) `Zn(OH)_(2)hArrZn^(++)+2OH^(-)` `:. K_(b)=([Zn^(++)][OH^(-)]^(2))/([Zn(OH)_(2)])`, `K_(w)=[H^(+)][OH^(-)]` `:. (K_(w)^(2))/(K_(b))=K_(b)` |
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| 76. |
Which is a buffer solution?A. `CH3COOH+CH_(3)COONa`B. `CH_(3)COOH+CH_(3)COONH_(4)`C. `CH_(3)COOH+NH_(4)CL`D. `NaOH+NaCl` |
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Answer» Correct Answer - A Buffer solution is a mixture of weak acid and its conjugate base. |
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| 77. |
A white salt is readily soluble in water and gives a colourless solution with a `pH` of about `9`. The salt would beA. `NH_(4)NO_(3)`B. `CH_(3)COONa`C. `CH_(3)COONH_(4)`D. `CaCO_(3)` |
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Answer» Correct Answer - B `pH` of `9` means the salt solution should be fairly basic. |
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| 78. |
The ionization constant of ammonium hydroxide is `1.77xx10^(-5)` at `298 K`. Hydrolysis constant of ammonium chloride isA. `5.65xx10^(-12)`B. `5.65xx10^(-10)`C. `6.50xx10^(-12)`D. `5.65xx10^(-13)` |
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Answer» Correct Answer - B `NH_(4)Cl` is a salt of strong acid and weak base, so `K_(h)=(K_(w))/(K_(b))=(10^(-14))/(1.77xx10^(-5))=5.65xx10^(-10)` |
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| 79. |
Which may be added to one litre of water to act a buffer?A. One mole of `CH_(3)COOH` and one mole of `HCl`B. One mole of `NH_(4)OH` and one mole of `NaOH`C. One mole of `NH_(4)Cl` and one mole of `HCl`D. One mole of `CH_(3)COOH` and `0.5` mole of `NaOH` |
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Answer» Correct Answer - D `underset(0.5)underset(1)(HC_(2)H_(3)O_(2))+underset(0)underset(0.5)(NaOH) rarr underset(0.5)underset(0)(C_(2)H_(3)O_(2)Na)+underset(0.5)underset(0)(H_(2)O)` This solution contains weak acid `+` its salt with strong base and thus acts as buffer. |
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| 80. |
`1 M NaCl` and `1 M HCl` are present in an aqueous solution. The solution isA. Not a buffer solution and with `pHlt7`B. Not a buffer solution with `pHgt7`C. A buffer solution with `pHlt7`D. A buffer solution with `pHgt7` |
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Answer» Correct Answer - A `pH` is less than `7` due to `HCl` but not buffer. |
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| 81. |
What is the difference in `pH` for `1//3` and `2//3` stages of neutralization of `0.1 M CH_(3)COOH` with `0.1 M NaOH`?A. `2 log 3`B. `2 log (1//4)`C. `2 log (2//3)`D. `2 log 2` |
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Answer» Correct Answer - D `CH_(3)COOH+OH^(-) rarrCH_(3)COO^(-)+H_(2)O` Difference in `pH` between `(1)/(3)` and `(2)/(3)` stages of neutralisation ` =[pK_(a)+log``((2//3)/(1//3))]-pK_(a)+log``((1//3)/(2//3))=2 log 2` |
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| 82. |
The correct relationship between the `pH` of isomolar solutions of sodium oxide `(pH_(1))`, sodium sulphide `(pH_(2))`, sodium selenide `(pH_(3))` and sodium telluride `(pH_(4))` isA. `pH_(1)gtpH_(2)gtpH_(3)gtpH_(4)`B. `pH_(1)ltpH_(2)ltpH_(3)~pH_(4)C. `pH_(1)ltpH_(2)~pH_(3)gtpH_(4)`D. `pH_(1)gtpH_(2)~pH_(3)gtpH_(4)` |
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Answer» Correct Answer - A Acidic character of non-metals ions increases down the group. |
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| 83. |
Let the solubilities of `AgCl` in pure water be `0.01 M CaCl_(2)`, `0.01 M NaCl` and `0.05 M AgNO_(3)` be `s_(1)`, `s_(2)`, `s_(3)` and `s_(4)` respectively. What is the correct order of these quantities? Neglect any complexation.A. `S_(1)gtS_(2)gtS_(3)gtS_(4)`B. `S_(1)gtS_(3)gtS_(2)gtS_(4)`C. `S_(1)gtS_(2)=S_(3)gtS_(4)`D. `S_(1)gtS_(3)gtS_(4)ltS_(2)` |
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Answer» Correct Answer - B `AgClhArrAg^(+)+Cl^(-)` In `CaCl_(2)` `underset(0.01)(CaCl_(2))hArrunderset(0.01)(Ca^(+2))+underset(2xx0.01)(2Cl^(-))` In `NaCl` `underset(0.01)(NaCl)hArrunderset(0.01)(Na^(+))+underset(0.01)(Cl^(-))` In `AgNO_(3)` `underset(0.05)(AgNO_(3))hArrunderset(0.05)(Ag^(+))+underset(0.05)(Cl^(-))` common ion effect is maximum in `AgNO_(3)` So, `S_(1)gtS_(3)gtS_(2)gtS_(4)` |
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| 84. |
How many hydrogen ions are present in `1ml` of a solution of `pH=13`?A. `6.02xx10^(13)`B. `6.02xx10^(12)`C. `6.02xx10^(7)`D. `6.02xx10^(5)` |
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Answer» Correct Answer - C `pH=13` ` -log[H^(+)] =13` or `[H^(+)]=10^(-13)"mole"//litre` `[H^(+)]` in `1 ml=10^(-16) "moles"` `1 "mole" H^(+)` contains `6.023xx10^(23)H^(+) ions` `:.` No. of `H^(+) ions` in `10^(-16) "moles"` `=6.023xx10^(23)xx10^(-16)=6.023xx10^(7)` |
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| 85. |
The rate constant at `25^(@)C` for the reaction of `NH_(4)^(+)` and `OH^(-)` to form `NH_(4)OH` is `4xx10^(10) M^(-1) sec^(-1)` and ionisation constant of aq. `NH_(3)` is `1.8xx10^(-5)`. The rate constant of proton transfer to `NH_(3)` isA. `1.8xx10^(-5)`B. `7.2xx10^(5)`C. `3.6xx10^(5)`D. `4.2xx10^(-5)` |
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Answer» Correct Answer - B `NH_(4)^(+)+OH^(-)overset(k_(1))(to) NH_(4)OH` , `k_(1)=4xx10^(10)` `NH_(4)OHoverset(K_(f))underset(K_(b))(hArr)NH_(4)^(+)+OH^(-)` `k_(eq)=(k_(f))/(k_(b))` `1.8xx10^(-5)=(k_(f))/(4xx10^(10)) implies k_(f)=7.2xx10^(5)` |
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| 86. |
`NH_(3)` gas dissolves in water to give `NH_(4)OH`. In this reaction, water acts asA. an acidB. a baseC. a saltD. a conjugate base |
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Answer» Correct Answer - A `H_(2)O` acts as an acid because it provides `H^(+)` to `NH_(3)`. |
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| 87. |
A certain weak acid has a dissociation constant `1.0xx10^(-4)`. The equilibrium constant for its reaction with a strong base is :A. `1.0xx10^(-4)`B. `1.0xx10^(-10)`C. `1xx10^(-10)`D. `1.0xx10^(-14)` |
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Answer» Correct Answer - C `HAhArrH^(+)+A^(-)` `K_(a)=([H^(+)][A^(-)])/([HA])` (`i`) Also `HA+B^(+)+OH^(-) rarr B^(+)+A^(-)+H_(2)O` `K_(eq.)=([H_(2)O][A^(-)])/([HA][OH])` (`ii`) By (`i`) and (`ii`), `=(K_(eq))/(K_(a))=(1)/([H^(+)][OH^(-)])=(1)/(K_(w))` `:. K_(eq)=(K_(a))/(K_(w))=(10^(-4))/(10^(-14))=10^(-10)` |
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| 88. |
The dissocication constant of a weak acid is `1.0xx10^(-5)`, the equilibrium constant for the reaction with strong base isA. `1.0xx10^(-5)`B. `1.0xx10^(-9)`C. `1.0xx10^(9)`D. `1.0xx10^(14)` |
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Answer» Correct Answer - C `HAhArrH^(+)+A^(-)` , `K_(a)=([H^(+)][A^(-)])/([HA])` (`i`) neutralization of the weak acid with strong base is `HA+OH^(-)hArrA^(-)+H_(2)O` `K=([A^(-)])/([HA][OH^(-)])` (`ii`) Dividing (`i`) by (`ii`), `(K_(a))/(K)=[H^(+)][OH^(-)]=K_(w)=10^(-14)` `K=(K_(a))/(K_(w))=(10^(-5))/(10^(-14))=10^(9)` |
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| 89. |
`pH` of a `10^(-10) M NaOH` is nearest toA. `10`B. `7`C. `4`D. `10` |
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Answer» Correct Answer - B Total concentration of `[OH^(-)]` in solution `=[OH^(-)]_(f rom water)+[OH]_(f rom NaOH)` `=10^(-7)_(a ppro x)+10^(-10)` `=` slightly more than `10^(-7)` So `pOH` should be slightly less than `7` |
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| 90. |
Which one of the following salt is most acidic in water?A. `NiCl_(2)`B. `BeCl_(2)`C. `FeCl_(3)`D. `AlCl_(3)` |
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Answer» Correct Answer - D `AlCl_(3)` on hydrolysis gives weak base and strong acid among all. |
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| 91. |
The aqueous solution of `FeCl_(3)` is acidic due toA. Acidic impuritiesB. IonisationC. HydrolysisD. Dissociation |
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Answer» Correct Answer - C `FeCl_(3)` is a salt of weak base `(Fe(OH)_(3))` and strong acid `(HCl)`. |
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| 92. |
Which of the following species is more soluble in water ?A. `M(OH)_(3) (K_(SP)=1xx10^(-35))`B. `M(OH)_(2) (K_(SP)=1xx10^(-30))`C. `MOH (K_(SP)=1xx10^(-28))`D. `MOH (K_(SP)=1xx10^(-26))` |
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Answer» Correct Answer - A Solubility of `M(OH)_(3)=4sqrt((K_(SP))/(27))=4sqrt((10^(-35))/(27))=7.8xx10^(-10)` Solubility of `M(OH)_(2)=3sqrt((K_(SP))/(4))=6.3xx10^(-11)` Solubility of `MOH=sqrt(K_(SP))=10^(-14)` |
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| 93. |
Which of the following salts when dissolved in water with get hydrolysed?A. `NaCl`B. `NH_(4)Cl`C. `KCl`D. `Na_(2)SO_(4)` |
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Answer» Correct Answer - B `NH_(4)Cl` is hydrolysed and gives `[H^(+)]` `NH_(4)Cl+H.OHhArrNH_(4)OH+HCl` `NH_(4)Cl+H.OHhArrNH_(4)OH+H^(+)` |
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| 94. |
Assertion : The `H_(3)O^(+)` has additional water molecules closely associated with it. Reason : In solid state the species `H_(5)O_(2)^(+)` and `H_(9)O_(4)^(+)` have been found to exist.A. If both assertion and reason are true and the reason is the correct explantion of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true. |
| Answer» Correct Answer - B | |
| 95. |
At `25^(@)C K_(b)` for `BOH=1.0xx10^(-12).0.01M` solution of `BOH` has `[OH^(-)]`:A. `1.0xx10^(-6) M`B. `1.0xx10^(-7) M`C. `1.0xx10^(-5) M`D. `2.0xx10^(-6) M` |
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Answer» Correct Answer - B `[OH^(-)]=C alpha= Csqrt((K_(b))/(C))` `=sqrt(K_(b).C)=sqrt(1.0xx10^(-12)xx0.01)=1.0xx10^(-7) M` |
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| 96. |
The solubility product of chalk is `9.3xx10^(-8)`. Calculate its solubility in gram per litreA. `0.3040 gram//litre`B. `0.0304 gram//litre`C. `2.0304 gram//litre`D. `4.0304 gram//litre` |
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Answer» Correct Answer - B `CaCO_(3)hArrCa^(2+)+CO_(3)^(2-)` Let the solubility of `CaCO_(3)` be `s` mole per litre `:. K_(SP)=[Ca^(2+)][CO_(3)^(2-)]=s.S` `:. S=sqrt(K_(sp))=sqrt(9.3xx10^(-8))=0.000304 "mole"//litre` Solubility in `g//L="mole"//litrexx` Molecular weight of `CaCO_(3)=0.000304xx100=0.0304 gram//litre` |
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| 97. |
Solubility of `AgCl` at `20^(@)C` is `1.435xx10^(-3) g per litre`. The solubility product of `AgCl` isA. `1xx10^(-5)`B. `1xx10^(-10)`C. `1.435xx10^(-5)`D. `108xx10^(-3)` |
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Answer» Correct Answer - B `S=1.435xx10^(-3)g//l`, `=(1.435xx10^(-3))/(143.5)=10^(-5)M` `K_(sp)=SxxS=10^(-10)` `(S^(2))=10^(-10)` |
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| 98. |
Baking soda isA. Basic saltB. Acidic saltC. Complex saltD. Double salt |
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Answer» Correct Answer - B `Na_(2)CO_(3)` has one replaceable hydrogen. |
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| 99. |
Which one of the following substances will be a mixed salt?A. `NaHCO_(3)`B. `Ca(OC l)Cl`C. `K_(2)SO_(4)Al_(2)(SO_(4))_(3).24H_(2)O`D. `Mg(OH)Br` |
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Answer» Correct Answer - B `CaCl_(2)` has two anions `Cl^(-)` and `Ocl^(-)` along with `Ca^(2+) ions`. |
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| 100. |
The compound whose `0.1 M` solution is basic isA. Ammonium acetateB. Calcium carbonateC. Ammonium sulphateD. Sodium acetate |
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Answer» Correct Answer - D `CH_(3)COONa` is a salt of weak acid, `(CH_(3)COOH)` and strong base `(NaOH)`. |
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