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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.
| 1051. |
Both temporary and permanent hardness is removed on boiling withA. `CO(OH)_(2)`B. `Na_(2)CO_(3)` (washing soda)C. `CaCO_(3)` (lime stone)`D. `CaO` (quick lime)` |
| Answer» Correct Answer - B | |
| 1052. |
Which of the following bicarbonate does not exist in solid state?A. `LiHCO_(3)`B. `NaHCO_(3)`C. `KHCO_(3)`D. `RbHCO_(3)` |
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Answer» Correct Answer - A Li bears diagonal relationship with Mg whose bicarbonate exists only in solution. |
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| 1053. |
Calcium hydride reacts with excess water to form :A. `CaO" and "H_(2)`B. `Ca(OH)_(2)" and "O_(2)`C. `Ca(OH)_(2)` onlyD. `Ca(OH)_(2)" and "H_(2)` |
| Answer» Correct Answer - D | |
| 1054. |
Oxidation state of K in `KO_(2)` is same as that in :A. `KO_(3)`B. `K_(2)O_(2)`C. `K_(2)O`D. `KOH` |
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Answer» Correct Answer - A::B::C::D Alkali metals show oxidation state of +1 (always) in combined state. |
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| 1055. |
In the formation of superoxide `M+O_(2)toMO_(2),` the metal M isA. LiB. NaC. KD. Ba |
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Answer» Correct Answer - C |
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| 1056. |
In acidic medium, the reaction of `H_(2)O_(2)` with potassium permanganate produces a compound in which the oxidation state of Mn is not?A. `0`B. `+2`C. `+3`D. `+4` |
| Answer» Correct Answer - A::C::D | |
| 1057. |
The superoxide `O_(2)^(-)` ion is stable only in presence of :A. NaB. KC. RbD. Cs |
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Answer» Correct Answer - B::C::D Large cations stabilise large anions. |
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| 1058. |
Several blocks of magnesium are fixed to the bottom of a ship to ?A. Make the ship lighterB. Keep away the sharksC. Prevent under sea rocksD. Precvent the corrosion. |
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Answer» Correct Answer - 4 |
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| 1059. |
Serveral blocks of magnesium are fixed to the bottom of a ship toA. prevent action of water and saltB. prevent puncturing by undersea rocksC. keep away from the sharksD. make the ship lighter |
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Answer» Correct Answer - D `Mg` due to lightness and toughness is used in ships. |
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| 1060. |
Pick out statement (s) which is/are not true about diagonal relationship of Li and Mg: A. Polarising powers of `Li^(o+)` and `Mg^(2+)` ions are almost the same. B. Like Li, Mg decomposes water very fast. C. LiCI and `MgCI_(2)` are deliquesent. D. Like Li, Mg readily reacts with liquid bromine at ordinary temperaure.A. I and IVB. II and IIIC. Only IID. II and IV |
| Answer» Correct Answer - C | |
| 1061. |
Statement-1: LiF and CsI have low solubility in water. Statement-2: Both have high lattice enthalpy.A. Statement-1 is True, Statement-2 is True. Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True. |
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Answer» Correct Answer - C The low solubility of LiF in water is due to its high lattice enthalpy whereas low solubility of CsI is due to smaller hydration enthalpy of its two ions. |
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| 1062. |
The low solubility of LiF and that of CsI in water are respectively due to which of the properties of the alkali metal ions ?A. Higher hydration enthalpy of `Li^(+)` , higher lattice enthalpy of `Cs^(+)`B. Smaller hydration enthalpy of `Li^(+)` , higher lattice enthalpy of `Cs^(+)`C. Smaller lattice enthalpy of `Li^(+)` , higher hydration enthalpy of `Cs^(+)`D. Smaller hydration enthalpy of `Li^(+)` , smaller lattice enthalpy of `Cs^(+)` |
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Answer» Correct Answer - D Due to small size , `Li^(+)` has a high lattice energy and due to the bigger size `Cs^(+)` has small hydration energy . |
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| 1063. |
The low solubility of LiF and that of CsI in water are respectively due to which of the properties of the alkali metal ions?A. Higher hydration enthalpy of `Li^(+)`, higher lattice enthalpy of `Cs^(+)`B. Smaller hydration enthalpy of `Li^(+)`, higher lattice enthalpy of `Cs^(+)`C. Smaller hydration enthalpy of `Li^(+)`, smaller lattice enthalpy of `Cs^(+)`D. Higher lattice enthlpy of `Li^(+)`, smaller hydration enthalpy of `Cs^(+)` |
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Answer» Correct Answer - D It is the correct answer |
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| 1064. |
(a) Why is LiF least soluble in water among the fluorides of alkali metals ? Justify the given (b) Justify the given order of mobilites of the alkali mteal cations in aqueous solution: `Li lt Na^(+) lt K^(+) lt Rb^(+) lt Cs^(+)` (c) Lithium is the only alkali metal which forms a nitride directly. Explain . (d) `E^(@)` for `M^(2+)(aq)toM(s)`(where M=Ca,Sr or Ba) is nearly constant. Discuss. |
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Answer» (a) Lithium fluoride (LiF) is of covalent nature because of the high polarising power of `Li^(+)` ion due to its very small size and high effective nuclear charge. It destorts the electron cloud of the `F^(-)` ion the maximum as compared to the cations of other alkali metals. It is therefore, least soluble in water. On the other hand, the fluorides of other alkali metals are generally ionic and are water soluble. (b) This is attributed to the hydration of the cation in water. As a result,size of the cation increases and its mobility decreases. Due to the smallest size, `Li^(+)` ion is hydrated to the maximum and exists as `Li^(+)` (aq) and has least mobility. `Cs^(+)` ion due to least hydration exists as `Cs^(+)` (aq) has maximum mobility. (c) Lithium is a very strong redcuing agent. As a result, it directly exists as `Cs^(+)` (aq) combines with nitrogen to form its nitride `(Li_(3)N)`. `3Li+N_(2) overset("Heat")toLi_(3)N_(2)` (d) The overall magnitude of reduction potential `(E^(@))` depends upon three factors. These are (i) sublimation enthalpy (ii) ionisation enthalpy and (iii) hydration enthalpy. In case of the metals listed, the overall magnitude of `E^(@)` values remain almost the same. Therefore, these metals have almost same reducing strength. |
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| 1065. |
Crystals of washing soda lose nine molecules of water when exposed to dry air. This phenomenon is know asA. DehydrationB. HydrationC. DeliquescenceD. Efforescence |
| Answer» Correct Answer - D | |
| 1066. |
Select the corrrect statement with prespect to the deep blue solution of a n alkali metal in liquid ammonia.A. Its paramagnetism decreases with increasing concentration.B. It has lower density than pure solvent (I,e.liquid ammonis).C. Its conductivity decreases with increasing concentration oto minimum at about 0.05 molar, thereafter it again increase.D. Evaporation of ammonia from the solution yields alkali metal. |
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Answer» Correct Answer - A::B::C::D |
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| 1067. |
`MgSO_(4)+NH_(4)Cl+Na_(2)HPO_(4) rarr` White crystalline precipitate.A. `MgCl_(2).MgSO_(4)`B. `MgSO_(4)`C. `Mg(NH_(4))PO_(4)`D. `Mg(PO_(4))_(2)` |
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Answer» Correct Answer - C `MgSO_(4)+NH_(4)Cl+Na_(2)HPO_(4) rarr Mg(NH_(4))PO_(4)` |
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| 1068. |
`MgSO_(4)` on reaction with `Na_(4)OH` and `Na_(2)HPO_(4)` forms a white crystalline precipitate. What is its formula?A. `Mg(NH_(4))PO_(4)`B. `Mg_(3)(PO_(4))_(3)`C. `MgCl_(2).MgSO_(4)`D. `MgSO_(4)` |
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Answer» Correct Answer - A |
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| 1069. |
Why alkali metals impart colour to the flame ? |
| Answer» Alkali metals have low ionization enthalpies . Their valence electrons easily absorb energy from the flame and are excited to higher energy levels . When these excited to higher energy levels . When these excited electrons return to the ground state , the absorbed energy is emitted in form of light . | |
| 1070. |
Which pair of the following chlorides do not impart colour to the flame ?A. `BeCl_(2) and SrCl_(2)`B. `BeCl_(2) and MgCl_(2)`C. `CaCl_(2) and BaCl_(2)`D. `BaCl_(2) and SrCl_(2)` |
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Answer» Correct Answer - B `BeCl_(2)` and `MgCl_(2)` do not impact colour to the flame due to their high ionization enthalpies . |
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| 1071. |
How many of the following metal chlorides impart characteristic colour to the lower oxidising flame? LiCl, NaCl, KCl, `BeCl_(2), MgCl_(2), CaCl_(2), SrCl_(2), BaCl_(2)` |
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Answer» Correct Answer - 3 Be and Mg have very high I.E. Hence do not impart colour to the flame. `Ca^(2+),Sr^(2+),Ba^(2+)` less volatile and impart colour to the flame in fusion zone. |
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| 1072. |
Which pair of the following chlorides does not impart color to the flame ?A. `BeCl_(2) " & " SrCl_(2)`B. `BeCl_(2) " & " MgCl_(2)`C. `CaCl_(2) " & " BaCl_(2)`D. `MgCl_(2) " & " CaCl_(2)` |
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Answer» Correct Answer - B |
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| 1073. |
In the synthesis of sodium carbonate, the recovery of ammonia is done by treating `NH_(4)Cl` with `Ca(OH)_(2)`. The by-product obtained in this process isA. `CaCl_(2)`B. `NaCl`C. NaOHD. `NaHCO_(3)` |
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Answer» Correct Answer - b `2NH_(4)Cl+Ca(OH)_(2)rarrCaCl_(2)+2NH_(2)+2H_(2)O` |
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| 1074. |
In the synthesis of sodium carbonate, the recovery of ammonia is done by treating `NH_(4)Cl` with `Ca(OH)_(2)`. The by-product obtained in this process isA. `CaCl_(2)`B. `NaCl`C. `NaOH`D. `NaHCO_(3)` |
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Answer» Correct Answer - A `CaCl_(2)` is the by-product. `2NH_(4)Cl + Ca(OH)_(2) to CaCl_(2) + 2NH_(3) + 2H_(2)O`. |
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| 1075. |
Phosphine, acetylene and ammonia can be formed by treating water withA. `Mg_(3) O_(2),Al_(4)C_(3),Li_(3)N`B. `Ca_(3)P_(2),CaC_(2),Ca(CN)_(2)`C. `Ca_(3)P_(2),CaC_(2),CaCN_(2)`D. `Ca_(3)P_(2),Mg_(2)C,NH_(4)NO_(3)` |
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Answer» Correct Answer - C |
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| 1076. |
When heated in steam, Mg burns brilliantly producing-A. `Mg(OH)_(2)`B. `MgO` and `H_(2)`C. `MgO` and `O_(2)`D. `MgO` and `O_(3)` |
| Answer» Correct Answer - B | |
| 1077. |
Initial setting of cement is mainly due toA. dehydration and gel formationB. dehydration and gel formationC. dehydration and dehydroylsisD. hydration and oxidation |
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Answer» Correct Answer - A initial setting of cement is due to hydration and gel formation. |
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| 1078. |
Assertion: When cement is mixed with water and left as such, it becomes hard mass. Reason: Setting of cement is exothermic process.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 |
| Answer» Correct Answer - B | |
| 1079. |
Assertion : Setting of cement is an endothermic process. Reason : Setting of cement involves hydration and rearrangement of the molecules of calcium aluminates and calcium silicates.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - d Assertion `:` It is exothermic process. Reason `:` Setting of cement takes place to give a hard masss. It is due to hydration of the molecules of the constituents `(` dicalcium silicate `26%`, tricalcium silicate `51%` and tricalcium aluminate `11%)` and their rearrangement. |
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| 1080. |
Which carbonate is most unstable and requires `CO_(2)` atmosphere to be stored?A. `BeCO_(3)`B. `MgCO_(3)`C. `SrCO_(3)`D. `BaCO_(3)` |
| Answer» Correct Answer - A | |
| 1081. |
Which of the carbonates given below is unstable in air and is kept in `CO_(2)` atmosphere to avoid decomposition?A. `BeCO_(3)`B. `MgCO_(3)`C. `CaCO_(3)`D. `BaCO_(3)` |
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Answer» Correct Answer - A `BaCO_(3)` is unstable in air and is kept in `CO_(2)` atmosphere to avoid decomposition and to check the forward reacthion `BeCO_(3) hArr beO + CO_(2)` |
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| 1082. |
Which of the carbonates given below is unstable in air and is kep in `CO_(2)` atmosphere to avoid decomposition .A. `BeCO_(3)`B. `MgCO_(3)`C. `CaCO_(3)`D. `BaCO_(3)` |
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Answer» Correct Answer - D Due to least electropositive character or least basicity of `Be(OH)_(2), BeCO_(3)` is less stable and hence decompose to give BeO and `CO_(2)` . Since the decomposition reaction is reversible , therefore to increase the stability of `BeCO_(3)` or to reverse the above equilibrium , `BeCO_(3)` is kept in an atmosphere of `CO_(2)` . `BeCO_(3) hArr BeO + CO_(2)` |
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| 1083. |
Bleaching powder and bleach solution are produced on a large scale and used in several hous-hold products. The effectiveness of bleach solution id often measured by iodometry. Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is:A. `CI_(2)O`B. `CI_(2)O_(7)`C. `CIO_(2)`D. `CI_(2)O_(6)` |
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Answer» Correct Answer - A Bleaching powder is `Ca(OCI)CI`. It contains `OCI^(-)` ion and the corresponding acid is HCIO. The anhydride of HCIO is : `underset(HOCI)overset(HOCI)(+) to H_(2)O + CI_(2)O` |
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| 1084. |
Several sodium compounds find use in industries . Which of the following compounds are used for textile industry ?A. `Na_(2)CO_(3)`B. `NaHCO_(3)`C. `NaOH`D. `NaCl` |
| Answer» Correct Answer - A::C | |
| 1085. |
The most abundant element among the following isA. MgB. CaC. SrD. Ra |
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Answer» Correct Answer - 2 |
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| 1086. |
Which one of the following is the most abundant alkali metal (in combinaed state) in nature ?A. LiB. NaC. CsD. K |
| Answer» Correct Answer - B | |
| 1087. |
The most abundant metal present in the human body isA. CaB. KC. FeD. Na |
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Answer» Correct Answer - 1 |
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| 1088. |
`CO_(2)` gas along with solid `(Y)` is obtained when sodium salt `(X)` is heated. `(X)` is again obtained when `CO_(2)` has is passed into `(Y)`. `X` & `Y` are-A. `Na_(2)CO_(3), Na_(2)O`B. `Na_(2)CO_(3), NaOH`C. `NaHCO_(3),Na_(2)CO_(3)`D. `Na_(2)CO_(3), NaHCO_(3)` |
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Answer» Correct Answer - C Only `NaHCO_(3)` can viberate `CO_(2)` on heating. |
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| 1089. |
The least abundant alkaline earth metal isA. BariumB. RadiumC. MagnesiumD. Lithium |
| Answer» Correct Answer - B | |
| 1090. |
which of the following configurations is correct for alkaline earth elements?A. `[Ne]2s^(2)2p^(2)`B. `[Ar]4s^(2)`C. `[Ar]3d^(10)4s^(1)`D. `[Ar] 3d^(10)4s^(2)` |
| Answer» Correct Answer - B | |
| 1091. |
When `SiCI_(4)` vapours are passed over hot Mg, the products formed areA. `SiCI_(2) + MgCI_(2)`B. `MgSi + CI_(2)`C. `Si+ MgCI_(2)`D. `MgSiCI_(6)` |
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Answer» Correct Answer - C Mg act as reducing agent. |
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| 1092. |
The reaction of sodium with water is highly exothermic the rate of reaction can be lowered by :A. Decreasing the temperatureB. Mixing with alcoholC. Mixing with acetic acidD. Making an amalgam |
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Answer» Correct Answer - D Making an amalgam |
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| 1093. |
In `[Be(H_(2)O)_(4)]^(2+)`,Be hydrobridisation isA. `sp^(3)`B. `sp^(2)`C. `dsp^(2)`D. sp |
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Answer» Correct Answer - 1 |
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| 1094. |
The products obtained on heating `LiNO_(3)` will beA. `LiNO_(2)+O_(2)`B. `Li_(2)O+NO_(2)+O_(2)`C. `Li_(3)N+O_(2)`D. `Li_(2)O+OH+O_(2)` |
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Answer» Correct Answer - b `2LINO_(3)overset(Delta)rarrLi_(2)O+2NO_(2)+(1)/(2)O_(2)` |
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| 1095. |
The products obtained on heating `LiNO_(3)` will beA. `Li_(2)O+NO_(2)+O_(2)`B. `Li_(3)+O_(2)`C. `Li_(2)O+NO+O_(2)``D. `LiNO_(3)+O_(2)` |
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Answer» Correct Answer - B |
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| 1096. |
The products obtained on heating `LiNO_(3)` will beA. `LiNO_(2) + O_(2)`B. `Li_(2)O + NO_(2) + O_(2)`C. `Li_(3)N + O_(2)`D. `Li_(2)O + NO + O_(2)` |
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Answer» Correct Answer - B `4LiNO_(3) overset(Delta)(to) 2 Li_(2)O + 4 NO_(2) + O_(2)`. |
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| 1097. |
The products obtained on heating `LiNO_(3)` will be |
| Answer» `4LiNO_(3) overset("Heat")(to) 2Li_(2)O + 4NO_(2) + O_(2)` | |
| 1098. |
Assertion : `Na_(2)ZnO_(2)` is water soluble whereas `Zn(OH)_(2)` is insoluble. Reason : Addition of `NaOH` solution to `ZnCl_(2)` gives white ppt. which dissolves on further addition of `NaOH` due to the formation of complex cation.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. 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 `ZnCl_(2)+2NaOH rarr Zn(OH)_(2)+2NaCl` `Zn(OH)_(2)+2NaOH rarr Na_(2)[ZnO_(2)]+2H_(2)O` `[Zn_(2)O]^(2-)` is a complex anion. |
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| 1099. |
Which will liberate hydrogen on reacting with hydrochloric acid ?A. CopperB. PhosphoursC. MercuryD. Magnesium |
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Answer» Correct Answer - D `Mg + 2HCI to MgCI_(2) + H_(2)` |
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| 1100. |
When sodium is reacted with limited supply of oxygen, the main compound formed isA. `Na_(2)O_(4)`B. `Na_(2)O`C. `Na_(3)O`D. `Na_(2)O_(2)` |
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Answer» Correct Answer - b `4Na+O_(2)rarr2Na_(2)O` |
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