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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. |
A sodium salt of unknown anion when treated with `MgCl_(2)` gives a white `ppt`. On boiling. The anion isA. `HCO_(3)^(o.)`B. `CO_(3)^(2-)`C. `SO_(4)^(2-)`D. `NO_(3)^(o.)` |
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Answer» Correct Answer - 1 |
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| 52. |
A sodium salt of unknown anion when treated with `MgCl_(2)` gives a white `ppt`. On boiling. The anion isA. `HCO_(3)^(-)`B. `NO_(3)^(-)`C. `CO_(3)^(2-)`D. `SO_(3)^(2-)` |
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Answer» Correct Answer - A `2NaHCO_(3)+MgCl_(2)rarr MgCO_(3)+2NaCl+H_(2)O` |
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| 53. |
A sodium salt of unknown anion when treated with `MgCl_(2)` gives a white `ppt`. On boiling. The anion isA. `HCO_(3)`B. `CO_(3)^(2-)`C. `NO_(3)^(-)`D. `SO_(4)^(2-)` |
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Answer» Correct Answer - A `MgCl_(2) +2NaHCO_(3)rarr Mg(HCO_(3)) (aq)+2NaCl` `Mg(HCO_(3))_(2)(aq) overset(Delta)rarr underset(("White ppt."))(MgCO_(3) uarr)+H_(2)O+CO_(2)darr.` |
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| 54. |
Suspension of slaked lime in water is known asA. lime waterB. quick limeC. milk of limeD. aqueous solution of slaked lime |
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Answer» Correct Answer - C Is the correct answer |
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| 55. |
Plaster of Paris is represented asA. `CaSO_(4) . 2H_(2)O`B. `CaSO_(4) . H_(2)O`C. `CaSO_(4) . (1)/(2) H_(2)O`D. `CaSO_(4)` |
| Answer» Correct Answer - C | |
| 56. |
Plaster of Paris is hardened byA. Liberating `CO_(2)`B. HydrationC. DehydrationD. Changing into `CaCO_(3)` |
| Answer» Correct Answer - b | |
| 57. |
`MgN_(2)` when reacted with water gives `NH_(3)` and HCl. However, `MgCl_(2)` does not give HCl when treated with water at room temperature. Assigne reason. |
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Answer» `Mg_(2)N_(2)` is a salt of strong base `Mg(OH)_(2)` and weak acid `NH_(3)`. It undergoes hydrolysis to evolve ammonia as follows: `Mg_(3)N_(2) + 3H_(2)O to 3Mg(OH)_(2) + 2NH_(3)` But `MgCI_(2)` is a salt of strong base and strong acid and does not undergoes hydrolysis with water. Therefore, HCI is not formed. |
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| 58. |
Dead burnt plaster isA. `CaSO_(4)`B. `CaSO_(4) . (1)/(2) H_(2)O`C. `CaSO_(4) . H_(2)O`D. `CaSO_(4) . 2 H_(2)O` |
| Answer» Correct Answer - A | |
| 59. |
Dead burnt plaster isA. `CaSO_(4)`B. `CaSO_(4) (1)/(2) H_(2)O`C. `CaSO_(4).H_(2)O`D. `CaSO_(4).2 H_(2)O` |
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Answer» Correct Answer - A `CaSO_(4)` is dead burnt cement. |
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| 60. |
Dead burnt plaster is:A. `CaSO_(4^.)2H_(2)O`B. `MgSO_(4^.)7H_(2)O`C. `CaSO_(4^.)1//2H_(2)O`D. `CaSO_(4)` |
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Answer» Correct Answer - 4 |
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| 61. |
Gypsum `CaSO_(4).2H_(2)O` on heating to about `120^(@)` forms a compound which has the chemical composition represented byA. `CaSO_(4)`B. `2CaSO_(4).H_(2)O`C. `CaSO_(4).H_(2)O`D. `2CaSO_(4).3H_(2)O` |
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Answer» Correct Answer - B `2underset("Gypsum")((CaSO_(4).2H_(2)O))overset(120^(@)C)underset("Dehydration")rarr underset("Plaster of Paris")(2CaSO_(4).H_(2)O)+3H_(2)O` |
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| 62. |
Give the chemical composition of the following : (a) Anhydrane (b) Fluid magnesia (c ) Dead burnt plaster (d) Sorel Cement (e ) Epsom salt (f) Magnesia mixture |
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Answer» (a) Anhydrane : It is magnesium perchlorate with the formula `Mg(CIO_(4))_(2)`. (b) Fluid magnesia : A 12% aqueous solution of `Mg(HCO_(3))_(2)` is called fluid magnesia. (c ) Dead burnt plaster : It is anhydrous `CaSO_(4)` (d) Sorel Cement : It is a hard mass generally used in dental filling. It is a paste of finely divided magnesium oxidation magnesium chloride along with fillers like soap stone and wood fluor. The chemical formula is `MgCI_(2).5MgOO.xH_(2)O` (e) Epson salt : It is hydrated magnesium sulphate wit formula `MgSO_(4).7H_(2)O`. (f) Magnesia mixture : It is a mixture of `MgCI_(2)`, `NH_(4)CI` used small amount of `NH_(3)`. It is used for the detetion of phosphate `(PO_(4)^(3-))` and aresenate `(AsO_(3)^(3-))` in qualitative analysis. |
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| 63. |
Gypsum `CaSO_(4).2H_(2)O` on heating about `120^(@)C` forms a compound which has the chemical composition isA. `CaSO_(4)`B. `2CaSO_(4).H_(2)O`C. `CaSO_(4).H_(2)O`D. `2CaSO_(4).3H_(2)O` |
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Answer» Correct Answer - 2 `underset("Gypsum")(2(CaOS_(4).2H_(2)O))underset(120^(@)C)overset(Delta)rarrunderset("Plaster of paris")(2CaSO_(4).H_(2)O+3H_(2)O` |
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| 64. |
Which is the composition of fusion mixture ?A. `K_(2)CO_(3) +NH_(4)Cl`B. `K_(2)CO_(3)+Na_(2)CO_(3)`C. `KNO_(3)+KCl`D. None of these |
| Answer» Correct Answer - D | |
| 65. |
The number of ultimater electrons in magnesium atom areA. 12B. 1C. 8D. 7 |
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Answer» Correct Answer - 3 |
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| 66. |
`KO_(2)` is-A. Normal oxideB. Super oxideC. SuboxideD. Peroxide |
| Answer» Correct Answer - B | |
| 67. |
Sodium burns in dry air to give `:`A. `Na_(2)O`B. `Na_(2)O_(2)`C. `NaO_(2)`D. `Na_(3)N` |
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Answer» Correct Answer - B |
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| 68. |
Select odd pair of name of chemical and its chemical composition.A. Soda ash : `Na_(2)CO_(3)`B. Caustic soda : `NaHCO_(3)`C. Washing soda : `NaHCO_(3)`D. Baking soda : `NaHCO_(3)` |
| Answer» Correct Answer - C | |
| 69. |
Magnesium powder burns in air to give :A. `Mg_(3)N_(2)`B. `MgCO_(3)`C. `Mg(NO_(3))_(2)`D. None |
| Answer» Correct Answer - A | |
| 70. |
Which of the following is sparingly soluble in water ?A. `Na_(2)CO_(3)`B. `LiCO_(3)`C. `K_(2)CO_(3)`D. `NaNO_(3)` |
| Answer» Correct Answer - B | |
| 71. |
Which of the following statement is not correct?A. Sodium chloride absorbs water and is hygroscopic.B. Common salt is used to clear snow on the road.C. Anhydrous `MgCl_(2)` can be prepared by heating a double salt of it ie., `MgCl_(2).NH_(4)Cl.6H_(2)O`.D. `CaSO_(4)` and `BaSO_(4)` are reacted with coke to produce CaS and BaS repectively. |
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Answer» Correct Answer - A |
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| 72. |
On heating sodium metal in a current of dry ammonia, the compound formed isA. Sodium amideB. Sodium azideC. Sodium nitrideD. Sodium hydride |
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Answer» Correct Answer - A `2na +2HN_(3)overset(Delta)to 2NaNH_(2) +H_(2)` |
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| 73. |
On heating sodium metal in a current of dry ammonia, the compound formed isA. Sodium nitriteB. Sodium hydride qC. Sodium amideD. Sodium nitrate |
| Answer» Correct Answer - C | |
| 74. |
When dry ammonia gas is passed over heated sodium (out of contact of air) the product forms isA. Sodium nitriteB. sodium hydrideC. Sodium amideD. Sodium azide |
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Answer» Correct Answer - C `2Na+2NH_(3)rarr 2NaNH_(2)+H_(2)` |
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| 75. |
Sodium burns in dry air to giveA. `Na_(2)O`B. `Na_(2)O_(2)`C. `NaO_(2)`D. `Na_(3)N` |
| Answer» Correct Answer - B | |
| 76. |
The non-radit active metal of II A group having least first ionisation potential isA. RadiumB. BerylliumC. ClaciumD. Barium |
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Answer» Correct Answer - 4 |
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| 77. |
Lime water containsA. Calcium hydroxideB. Calcium oxalateC. Calcium hydrideD. Calcium sulphate |
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Answer» Correct Answer - 1 |
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| 78. |
On heating sodium metal in the current of dry ammonia leads to the formation of which gas-A. `NaNH_(2)`B. `NaN_(3)`C. `NH_(3)`D. `H_(2)` |
| Answer» Correct Answer - D | |
| 79. |
The metal not found in the native state is-A. KB. `Cu`C. `Ag`D. `Au` |
| Answer» Correct Answer - A | |
| 80. |
(A-Group IIA compound, C is a pungent odour, coloured and paramagnetic)A & E in the above reaction sequence are:A. `MgCO_(3)&NaNO_(2)`B. `Mg(NO_(3))_(2)&Na_(2)CO_(3)`C. `Mg(NO_(2))_(2),NaNO_(2)`D. `Mg(NO_(3))_(2),NaNO_(3)` |
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Answer» Correct Answer - D |
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| 81. |
`Be(IIA)` shows different behaviour as compared to other elements of the same group the reason isA. Small size and high electronegativityB. Small size and low electronegativityC. Bigger size and low ionization energyD. Bigger size and large ionic radius |
| Answer» Correct Answer - A | |
| 82. |
The order of thermal stability of carbonates of IIA group is :A. `BaCO_(3)gtSrCO_(3)gtCaCO_(3)gtMgCO_(3)`B. `MgCO_(3)gtCaCO_(3)gtSrCO_(3)gtBaCO_(3)`C. `CaCO_(3)gtSrCO_(3)gtBaCO_(3)gtMgCO_(3)`D. `MgCO_(3)=CaCO_(3)gtSrCO_(3)gtSrCO_(3)=BaCO_(3)` |
| Answer» Correct Answer - A | |
| 83. |
The reactivity of IA elements is due to-A. Low I.P.B. Large atomic sizeC. Low heat of atomizationD. All the above |
| Answer» Correct Answer - D | |
| 84. |
Strong reductant in IIA and IA group is-A. `Ba,Li`B. `Li,Be`C. `Cs,Ba`D. `Ba,Cs` |
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Answer» Correct Answer - A `Ba & Li` |
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| 85. |
Which of the following correctly represents the increasing order of densities IA group elements?A. `Li lt K lt Na lt Rb`B. `Li lt Na gt K gt Rb`C. `Li lt Na ltK gt Rb`D. `Li lt Nagt K = Rb` |
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Answer» Correct Answer - A |
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| 86. |
Which of the following property does not change regularly down the group in the case of IA group metals ?A. DensityB. Hydration EnthalpyC. Ionization EnthalpyD. Melting point |
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Answer» Correct Answer - A |
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| 87. |
The reducing power of a metal depends on various factors. Suggest the factor which makes Li, the strongest reducing agent in aqueous solution.A. Sublimation enthalpyB. Ionisation enthalpyC. Hydration enthalpyD. Electron-gain enthalpy |
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Answer» Correct Answer - C The size of `Li^(+)` ion is very small. Therefore, hydration enthalpy of `Li^(+)` (aq) ion is very high. (`Delta_(H)` Hydration = 480 kJ) This is responsible for the reducing nature of lithium (Li). |
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| 88. |
The reducing power of a metal depends on various factors. Suggest the factor which makes Li, the strongest reducing agent in aqueous solution.A. Sublimation enthalpyB. Ionisation enthalpyC. Hydration enthalpyD. Electron gain enthalpy |
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Answer» Correct Answer - C Hydration enthalpy of `Li^(+)` is highest among all other alkali metal due to its smaller size. Therefore, `Li^(+)` acts as a strong reducing agent . |
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| 89. |
The reducing power of a metal depends on various factors . Suggest the factor which makes Li, the strongest reducing agent in aqueous solution .A. Sublimation enthalpyB. Ionisation enthalpyC. Hydration enthalpyD. Electron gain enthalpy |
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Answer» Correct Answer - C Due to small size of the`Li^(+)` , its hydration enthalpy is the highest and hence Li is the strongest reducing agent . |
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| 90. |
Assertion: `NaCI` when exposed in air it becomes wet. Reason: `NaCI` contains hygroscopic impurities like `CaCI_(2), MgCI_(2)` etc.A. If both Assertion & Reason are True & the Reason is a correct explanation of the AssertionB. If both Assertion & Reason are True but Reason is not a correct explanation of the AssertionC. If Assertion is True but the Reason is FalseD. If both Assertion & Reason are False |
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Answer» Correct Answer - A `CaCI_(2) & MgCI_(2)` easily get hydrated |
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| 91. |
Sodium is heated in air at `300^(@)C` to form X.X absorbs `CO_(2)` and forms `Na_(2)CO_(3)` and Y. Which of the following is Y ?A. `H_(2)`B. `O_(2)`C. `H_(2)O_(2)`D. `H_(2)O` |
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Answer» Correct Answer - B `2NA +O_(2) overset(300^(@)C)to Na_(2) O_(2) (X),` `underset((X))(2Na _(2)O_(2))+2CO_(2) to 2Na_(2) CO_(3) + underset((Y))(O_(2))` |
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| 92. |
A substance absorbs `CO_(2)` and violently reacts with water. The substance isA. `CaCO_(3)`B. `CaO`C. `H_(2)SO_(4)`D. `ZnO` |
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Answer» Correct Answer - B `Ca+CO_(2)rarr CaCO_(3)` `CaO+H_(2)O rarr Ca(OH)_(2)` |
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| 93. |
In the following pairs , each number produces the same gas when reacts with water ?A. `K , KO_(2)`B. `Na, Na_(2)O_(2)`C. `Ca, CaH_(2)`D. `Ba, BaO_(2)` |
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Answer» Correct Answer - C Both Ca, `CaH_(2)` react with `H_(2)O` to produce `H_(2)` gas . `Ca + 2 H_(2) O to Ca(OH)_(2) + H_(2)` `CaH_(2) + 2 H_(2)O to Ca(OH)_(2) + 2H_(2)` In contrast , K reacts with `H_(2)O` to produce `H_(2)` but `KO_(2)` produces `O_(2)` (or `O_(2) + H_(2)O`) , Na produces `H_(2)` but `Na_(2)O_(2)` produces `O_(2)`. Similarly , Ba produces `H_(2)` but `BaO_(2)` produces `O_(2).` |
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| 94. |
When a substance `A` reacts with water it produces a conbustible gas `B` and a solution of substance `C` in water. When another substance `D` reacts with this soution of `C`, it also produces the same gas `B` on warming but `D` can produce `B` on reaction with dilute sulphuric acid at room temperature. `B` on reaction with dilute sulphuric acid at room tempreture. `A` imparts a golden yellow colour to a smokeless flame of bunsen flame. `A,B,C` and `D` are respectively.A. `Na,H_(2),NaOH" and "Zn`B. `K, H_(2), KOH" and "Zn`C. `K,H_(2),NaOH" and "Zn`D. `Ca,H_(2)O,CaCOH_(2)" and "Zn` |
| Answer» Correct Answer - A | |
| 95. |
Electronic congiguration of caseium isA. `[At]4s^(1)`B. `[Kr]5s^(1)`C. `[Xe]6s^(1)`D. `[Rn]7s^(1)` |
| Answer» Correct Answer - C | |
| 96. |
Which of the following carbides on hydrolysis does not form methane?A. `Be_(2)C`B. `CaC_(2)`C. `SrC_(2)`D. `Mg_(2)C_(3)` |
| Answer» Correct Answer - B::C::D | |
| 97. |
Which of the following are ionic carbides ?A. `CaC_(2)`B. `Al_(4)C_(3)`C. SiCD. `Be_(2)C` |
| Answer» Correct Answer - A::B::D | |
| 98. |
Which of the following carbides on treatment with water give methane ?A. `Al_(4)C_(3)`B. `CaC_(2)`C. `VC`D. `SiC` |
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Answer» Correct Answer - A `Al_(4)C_(3)+HOH rarr 4AI(OH)_(3)+3CH_(4)` |
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| 99. |
The hydroxides and carbonates of sodium and potassium are easily soluble in water the corresponding compounds of magnesium and calcium are springly soluble. Explain. |
| Answer» All the compounds are crystalline solids and their solubility in water is guided by both lattice enthalpy and hydration enthalpy. In case of sodium and potassium compounds, the magnitude of lattice enthalpy is quite small as compared to hydration, enthalpy since the catonic sizes are large. Therefore, the compounds of sodium and potassium that are mentioned, radily dissolve in water. However, in case of corresponding magnesium and calcium compounds, the cations have smaller sizes and more magnitude of positive charge. This means that their lattice enthalpies are more as compared to the compounds of sodium and potassium, Therefore,the hydroxides and carbonates of these metals are only sparingly soluble in water. | |
| 100. |
Sodium peroxide which is yellow solid , when exposed to air becomes white due to the formation ofA. `H_(2)O_(2)`B. `Na_(2)O`C. `Na_(2)O and O_(3)`D. `NaOH and Na_(2)CO_(3)` |
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Answer» Correct Answer - D In presence of moisture and `CO_(2)` present in air , `Na_(2)O_(2)` is converted into NaOH and `Na_(2)CO_(3)` respectively both of which are white `Na_(2)O_(2) + H_(2) O to 2 NaOH + H_(2)O_(2)` `2 Na_(2) O_(2) + 2 CO_(2) to 2 Na_(2) CO_(3) + O_(2)` or `Na_(2)O_(2) + H_(2)O + CO_(2) to Na_(2)CO_(3) + H_(2)O_(2)` |
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