InterviewSolution
Saved Bookmarks
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.
| 1. |
For two ionic solids, `CaO` and `KI`, which of the following statements is false?A. Lattice enthalpy of `CaO` is much higher than that of `KI`.B. `CaO` has high melting point.C. `KI` has low melting point.D. `KI` is soluble in benzene. |
|
Answer» Correct Answer - D Due to lower lattice enthalpy of `KI` as compared to `CaO`, the melting point of `KI` is lower than that of `CaO`. `KI` is ionic, so insoluble in bezene. |
|
| 2. |
As the nuclear charge increases from neon to calcium, the orbital energiesA. IncreaseB. Increases very rapidlyC. increases very slowlyD. Fall |
| Answer» Correct Answer - D | |
| 3. |
A compound `(A)` on heating in Busen flame imparts brick red colouration. `(A)` on heating gives `CO_(2)` gas and a residue `(B)`. The residue `(B)` when treated with water gives `(c )`. On passing an excess of `CO_(2)` through `(C )` in water, a clear solution `(D)` is obtained. On boiling `(D)`, compound `(A)` is reformed. Residue `(B)` isA. `CaO`B. `CaO_(2)`C. `SrO`D. `BaO` |
|
Answer» Correct Answer - A Compound `(A)` imparts brick red colouration to the Bunsen flame, hence element present in it is `Ca`. On heating `(A),CO_(2)` is evolved, hence `(A)` is `CaCO_(3)`. `underset((A))(CaCO_(3))overset(Delta)rarrunderset("Residue")underset((B))(CaO)+CO_(2)uarr.("Residue"(B)is CaO)` `underset((B))(CaO)+H_(2)Orarrunderset((C))(Ca(OH)_(2)) [(C) is Ca(OH)_(2)]` `Ca(OH)_(2) +H_(2)O +underset("Excess")(CO_(2)) rarr underset((D))(Ca(HCO_(3))_(2)` `underset((D))(Ca(HCO_(3))_(2) overset(Delta)rarr underset((A))(CaCO_(3) +H_(2)O +CO_(2)` |
|
| 4. |
A metal `M` readily forms water soluble `MSO_(4)` water insoluble `M(OH)_(2)` and oxide `MO` which becomes inert on heating. The hydroxide is soluble in `NaOH`. Then `M` is:A. `Be`B. `Mg`C. `Ca`D. `Sr` |
|
Answer» Correct Answer - A Given, `M` reacts to give `MSO_(4)`, which is water soluble. `M` reacts to give `M (OH)_(2)`, which is water insoluble. `M` reacts to give `MO`, which becomes inert on heating. `M(OH)_(2)` is soluble in `NaOH`, this indicates that `M` is `Be`, since only `Be`, due to its small size and high ionisation enthalpy, is amphoteric and gives `M(OH)_(2)` which dissolves in `NaOH`. `Be(OH)_(2)+2NaOHrarrNa_(2)BeO_(2)+2H_(2)O` other facts given are true for `Be` and not for others. |
|
| 5. |
Two metals `(A)` and `(B)` belong to the same group of the periodic table. Metal `(A)` forms and insoluble oxide but a soluble sulphate, metal `(B)` forms a soluble oxide but an insoluble oxide but an insoluble sulphate. Both metals `(A)` and `(B)` form hydroxides which are soluble in alkalis. `(A)` and `(B)` areA. `Ba` and `Mg`B. `Na` and `K`C. `Mg` and `Ba`D. `K` and `Rb` |
|
Answer» Correct Answer - C `MgO` is insoluble, whereas `MgSO_(4)` is soluble, whereas `BaO` is soluble, but `BaSO_(4)` is insoluble. |
|
| 6. |
Which of the follwing forms covalent compound?A. `Be`B. `Mg`C. `Ca`D. `Sr` |
|
Answer» Correct Answer - A Due to small size and `+2` charge on `Be`, charge/radius ratio is the highest and `Be` forms covalent compound. |
|
| 7. |
`CaC_(2)` reacts with water to giveA. MethaneB. EthaneC. EthyleneD. Acetylene |
|
Answer» Correct Answer - D `CaC_(2)+2H_(2)OrarrCa(OH)_(2)+underset(("Acetylene"))(C_(2)H_(2))` |
|
| 8. |
`Be_(2)+H_(2)OrarrBeO+X` `CaC_(2)+H_(2)OrarrCa(OH)_(2)+Y` `Mg_(2)C_(3)+H_(2)OrarrMg(OH)_(2)+Z` Identify `(X),(Y)` and `(Z)`. |
|
Answer» `Be_(2)C+H_(2)OrarrBeO+underset((X))(CH_(4))` `CaC_(2)+2H_(2)OrarrCa(OH)_(2)+underset((Y))(C_(2)H_(2))` `Mg_(2)C_(3)+H_(2)OrarrMg(OH)_(2)+H_(2)C=underset(Z)(CHCH_(3))` Hence, `(X)impliesCH_(4),(Y)impliesC_(2)H_(2),ZimpliesH_(2)C=CHCH_(3)` |
|
| 9. |
On treatment with cold water, an element `(A)` reacted quietly liberating a colourless, odourless gas `(B)` and a basic solution `(C )`. Lithium reacted with `(B)` yielding a solid product `(D)` which effervesced with water to give a stongly basic solution `(E)` and gas `(F)`. When `CO_(2)` was bubbled through solution `(C )`, initially a white ppt. `(G)` was formed, but this redissolved forming solution `(H)` when more `CO_(2)` was passed, precipitate `(G)` effervesced when moistened with conc `HCl` and gave a brick red colouration to the bunsen flame. When `(G)` was heated with carbon at `1000^(@)C`, a caustic white compound `(I)` was formed, which when heated with `N_(20` at `1000^(@)C` gave a solid `(J)` of some commercial importance. Identify `(A)` to `(J)` and explain the reactions. |
|
Answer» `underset("Element")(Given, (A))+H_(2)Orarrunderset(gas)underset("odourless")underset("Colourless",)(B)+underset("Solution")underset("Basic")(C )` `Li+(B)rarrunderset("Solid product")(D)` `(D)+H_(2)Orarrunderset("Solution")underset("basic")underset("Strogly")(E)+(F)_(Gas)` `(C )+CO_(2(g))rarrunderset("White ppt".)((G))overset(CO_(2))(rarr)underset("Solution")underset("to give a")underset("redissolved")underset("White ppt".)((H))` `(G)+"conc" HClrarr{:("Effevescence produced" and),("gave brick red colouration"),("to Bunshen flame".):}` `(G)+"Carbon"` `overset(1000^(@)C)(rarr)underset("Compound")underset("white")underset("Caustic")((I)) overset(N_(2))underset(1000^(@)C)(rarr) underset("importance")underset("commercial")underset("Solid having")((J))` Solution: Since `(G)`gives brick red colouration to Bunshen flame it seems `(A)` is calcium. `underset((A))(Ca)+2H_(2)Orarrunderset("Basic solution")underset((C))(Ca(OH)_(2))+underset((B))(H_(2))` `2Li+underset((B))(H_(2))rarrunderset((D))(LiH_((s))` `LiH_((s))underset((D))+H_(2)Orarrunderset((G))(LiOH)+H_(2)` `underset((G))(CaCO_(3))+CO_(2)+H_(2)OrarrCaunderset(H)((HCO_(3))_(2))` `underset((G))(CaCO_(3))+underset(conc)(2HCl)rarrCaCl_(2)+H_(2)O+CO_(2)uarr` `underset((G))(CaCO_(3))+4Coverset(1000^(@)C)(rarr)underset((I))(CaC_(2))+3CO` `underset((G))(CaCO_(3))+4Coverset(1000^(@)C)(rarr)underset(I)(CaC_(2))+3CO` `underset((I))(CaC_(2))+N_(2)rarrunderset("Nitrolim")underset((J))(CaCN_((2))+C` |
|
| 10. |
Limestone is a naturally occuring form of calcium carbonate. It is used as building materials and also for manufacture of other building materials such as portland cement. It is used for the production of quickline and slaked lime which have wide applications in chemical, metallugical and construction industry. The pure `CaCO_(3)`, called precipitated calcium carbonate, is used extensively as filler, providing bulk to materials such as paint, plastics, printing links and rubber. it is also used in toothpastes, cosmetics and antacids. Quicklime and slaked lime are the cheapest and the most widely used bases for neutralising unwanted acids. Lime is used to neutralise acidic soils. An important application of quicklime is in air pollution control for the removal of `SO_(2)` in electric power plants. slaked lime is used in the manufature of other alkalis and bleacing powder, in sugar refinig, in tanning hide and in water softening. Chemical compound `(A)` is used to remove temporary hardness from water. It reacts with `Na_(2)CO_(3)` to generated caustic soda. when `CO_(2)` is passed through `(A)` it turns cloudy. What is `(A)`?A. `CaCO_(3)`B. `Ca(HCO_(3))_(2)`C. `Ca(OH)_(2)`D. `CaCl_(2)` |
|
Answer» Correct Answer - C `Ca(OH)_(2)+Ca(HCO_(3))_(2)rarr2CaCO_(3)darr+2H_(2)O` `Ca(OH)_(2)+Na_(2)CO_(3)rarrCaCO_(3)+2NaOH` `Ca(OH)_(2)+CO_(2)rarrCaCO_(3)+H_(2)O` |
|
| 11. |
Limestone is a naturally occuring form of calcium carbonate. It is used as building materials and also for manufacture of other building materials such as portland cement. It is used for the production of quickline and slaked lime which have wide applications in chemical, metallugical and construction industry. The pure `CaCO_(3)`, called precipitated calcium carbonate, is used extensively as filler, providing bulk to materials such as paint, plastics, printing links and rubber. it is also used in toothpastes, cosmetics and antacids. Quicklime and slaked lime are the cheapest and the most widely used bases for neutralising unwanted acids. Lime is used to neutralise acidic soils. An important application of quicklime is in air pollution control for the removal of `SO_(2)` in electric power plants. slaked lime is used in the manufature of other alkalis and bleacing powder, in sugar refinig, in tanning hide and in water softening. The drying agent which absorbs `CO_(2)` and reacts violently with water isA. Sodium carbonateB. QuicklimeC. Conc `H_(2)SO_(4)`D. Alcohol |
|
Answer» Correct Answer - B `CaO+CO_(2)rarrCaCO_(3)` `CaO+H_(2)OrarrCa(OH)_(2)` |
|
| 12. |
Limestone is a naturally occuring form of calcium carbonate. It is used as building materials and also for manufacture of other building materials such as portland cement. It is used for the production of quicklime and slaked lime which have wide applications in chemical, metallurgical and construction industry. The pure `CaCO_(3)`, called precipitated calcium carbonate, is used extensively as filler, providing bulk to materials such as paint, plastics, printing links and rubber. it is also used in toothpastes, cosmetics and antacids. Quicklime and slaked lime are the cheapest and the most widely used bases for neutralising unwanted acids. Lime is used to neutralise acidic soils. An important application of quicklime is in air pollution control for the removal of `SO_(2)` in electric power plants. slaked lime is used in the manufacture of other alkalis and bleaching powder, in sugar refining, in tanning hide and in water softening. The substance not likely to contain `CaCO_(3)` isA. DolomiteB. A marble statueC. Calcined gypsumD. Sea shells |
|
Answer» Correct Answer - A Calcined gypsum is `CaSO_(4)`. |
|
| 13. |
One mole of magnesium nitride on reaction with an excess of water givesA. One mole of `NH_(3)`B. Two moles of `NH_(3)`C. One mole of `HNO_(3)`D. Two moles of `HNO_(3)` |
|
Answer» Correct Answer - B `Mg_(3)N_(2)+6H_(2)Orarr3Mg(OH)_(2)+2NH_(3)` |
|
| 14. |
Which of the folowing undergoes disproportionation?A. `Ba^(2+)`B. `Ba^(o+)`C. `BaH_(2)`D. `BaSO_(4)` |
|
Answer» Correct Answer - B `2Ba^(o+)rarrBa^(2+)+Ba` Due to less stability of `overset(o+)(Ba)`, it undergoes disproportionation. |
|
| 15. |
One mole of calcium phosphorus on reaction with excess water givesA. `1 mol` of phophineB. `2 mol` of phosphoric acidC. `2 mol` of phosphoric acidD. `1 mol` of phosphoric pentoxide |
|
Answer» Correct Answer - C Phosphine gas is obtained `Ca_(3)P_(2)+6H_(2)Orarr3Ca(OH)_(2)+2PH_(3)` |
|
| 16. |
Select the correct statements about barium:A. It shows photoelectric effect.B. It is silvery white metal.C. It forms `Ba(NO_(3))_(2)` which is used in preparation of green fire.D. Its ionisation enthalply is less than radium. |
| Answer» Correct Answer - B::C::D | |
| 17. |
Soduim sulphate is soluble in water but barium sulphate is sparingly soluble becauseA. The hydration enthalpy of `Na_(2)SO_(4)` is more than its lattice enthalpy.B. The lattice enthalpy of `BaSO_(4)` is more than its hydration enthalpy.C. The lattice enthalpy has no role to play in solubility.D. The lattice enthalply of `Na_(2)SO_(4)` is more than its hydration enthalpy. |
| Answer» Correct Answer - A::B | |
| 18. |
Which of the folowing elements form peroxides when heated in excess of air?A. `K`B. `Na`C. `Ba`D. `Ca` |
|
Answer» Correct Answer - B::C::D `Na+O_(2)rarrNa_(2)O_(2)` `Ca+O_(2)rarrCaO_(2)` `Ba+O_(2)rarrBaO_(2)` |
|
| 19. |
Barium salts impart _________colour to the flame. |
| Answer» Correct Answer - Apple green | |
| 20. |
(a). Which alkaline earth metals do not give characteristic colour to the Bunsen flame? (b). Why alkaline earth metals do not form tripositive ions? (c ). Why alkaline earth metals are diamagnetic, but alkali metals are paramagnetic? (d). Why the first inonisation enthaply pf alkaline earth matals is higher than those of corresponding alkali metals? (e). Why alkaline earth metals are less electropositive than corresponding alkali metals? |
|
Answer» a. `Be` and `Mg` do not give characteristic colour to the bunsen flame. B. General electronic configuration of alkaline earth metals is `ns^(2)` preceded by noble gas core. After the removal of two electrons, bipositive cation formed acquires a stable noble gas configuration. for the removal of the third electron, a very large amount of energy is required and that is why alkaline earth metlas do not form tripositive ion, `M^(3+)`. `underset(2p^(6)3s^(2))(Mg)overset(IE_(1))underset(-e^(Θ))(rarr)underset(2p^(6)3s^(1))(Mg^(o+))overset(IE_(2))underset(-e^(Θ))(rarr)underset(2p^(5)3s^(0))underset(Mg^(3+))underset(-e^(Θ)darrIE_(3))underset("Stable noble gas configuration")underset(2p^(6)3s^(0))(Mg^(2+))` c. In case of alkaline earth metals, the general electronic configuration is `ns^(2)`. Due to the presence of paired electons in their atoms, alklaline earth metals are diamagnetic. In case of alkali metals, general electronic configuration is `ns^(1)`. Due to the presence of unpaired electron, alklai metals are paramagnetic. d. Alkaline earth metals have smaller size as compared to corresponding alkali metals due to increases charge, as a result the higer amount of energy is required for the removal of an electorn from the valence shell. that is why the first ionisation enthalpy of alklaline earth metal is higher than the corresponding alklai metal. e. Alkaline earth metals have smaller size as compared to alkali metals. Hence, valence shell electrons are more tightly bound to the nucles and ionisation entyhalpy of alkaline earth metals is more is more as compared to alkali metals. consequently, they have less tendency to lose valence shell electrons and are less electropositive as compared to alkali metals. |
|
| 21. |
Typical elements is the name given to the elements ofA. Zero groupB. Group `2`C. `2nd and 3rd` periodD. Group `1` |
| Answer» Correct Answer - B | |
| 22. |
Assertion (A): Magnesium does not impart any characteristic colour to the flame. Reason (R ): Due to small size and high effective nuclear charge, magnesium requires a large amount of energy for excitation of electrons.A. If both `(A)` and `(R )` are correct and `(R )` is the correct explanation of `(A)`.B. If both `(A)` and `(R )` are correct, but `(R )` is not the correct explanation of `(A)`.C. If `(A)` is correct, but `(R )` is incorrect.D. If `(A)` is incrrect, but `(R )` is correct. |
| Answer» Correct Answer - A | |
| 23. |
Assertion (A): magnesium is not present in enamel of human teeth. Reason (R ): Magnesium is an essential elements for biological functions of human beings.A. If both `(A)` and `(R )` are correct and `(R )` is the correct explanation of `(A)`.B. If both `(A)` and `(R )` are correct, but `(R )` is not the correct explanation of `(A)`.C. If `(A)` is correct, but `(R )` is incorrect.D. If `(A)` is incrrect, but `(R )` is correct. |
| Answer» Correct Answer - B | |
| 24. |
Anhydrous `MgCl_(2)` is obatined by heating hydrate salt with _____. |
|
Answer» Correct Answer - Dry `HCl` Anhydrous `MgCl_(2)` is obtained by heating the hydrated salt with dry `HCl`. `MgCl_(2).6H_(2)Ooverset(Dry HCl)rarrMgCl_(2)+6H_(2)O` |
|
| 25. |
Anhydrous `MgCl_(2)` is obatined by heating hydrate salt, `MgCl_(2).6H_(2)O`.A. Strongly in airB. In presnence of cokeC. In presence of conc `H_(2)SO_(4)` which absorbs moistureD. In presence of dry `HCl` gas |
| Answer» Correct Answer - D | |
| 26. |
(a) Why does the solubility of alkaline earth metal hydroxides in water increase down the group. (b). Why does the solubility of alkaline earth metal carbonates and sulphates in water decrease doewn the group? |
|
Answer» a. Among alkaline earth metal hydroxides, the anion being common, the cationic radius will influence the lattice enthalpy.Since lattice enthalpy decreases much more than the hydration enthalpy with increasing ionic size, the solubility increases down the group `(darr)`. b. The size of anions being much larger as compared to cations, the lattice enthalpy will remain almost constant within a particular group. Since the hydration enthalpy decreases down the group, solubility will decreases as found for alkaline earth metal carbonates and sulphates. |
|
| 27. |
(a). Why sodium chloride is added during electrolysis of fused anhydrous magnesium chlroride? (b). Why magnesium oxide is used for the lining of steel making furnace? |
|
Answer» a. Sodium chloride `(NaCl)` is added to lower the fusion temperature of magnesium chloride `(MgCl_(2))` and to make the mixture as a good conductor of electricity. b. `MgO` is used for the lining of steel making funase as it forms slag with the impurities and thus helps in removing them from iron. |
|
| 28. |
The most abundant alkaline earth metal is ________. |
| Answer» Correct Answer - Calcium | |
| 29. |
The basic chartacter of the alkaline earth metal hydroxides is as follows:A. `Mg(OH)_(2)gtBa(OH)_(2)gtCa(OH)_(2)gtSr(OH)_(2)`B. `Be(OH)_(2)gtSr(OH)_(2)gtCa(OH)_(2)gtMg(OH)_(2)`C. `Sr(OH)_(2)gtCa(OH)_(2)gtBa(OH)_(2)gtMg(OH)_(2)`D. `Mg(OH)_(2)gtBa(OH)_(2)gtSr(OH)_(2)gtCa(OH)_(2)` |
|
Answer» Correct Answer - B Basic character increases down the group due to increase in polarity of `M-OH` bond. |
|
| 30. |
Which of the following on thermal decomposition yields a basic as well as an acidic oxide?A. `KClO_(3)`B. `Na_(2)CO_(3)`C. `NaNO_(3)`D. `CaCO_(3)` |
|
Answer» Correct Answer - D `CaCO_(3)overset(Delta)(rarr)underset("oxide")underset("Basic")(CaO)+underset("oxide")underset("Acidic")(CO_(2)` |
|
| 31. |
Which of the following metal is the most difficult to extract from its oxide?A. `Cs`B. `Ca`C. `Mg`D. `Ag` |
| Answer» Correct Answer - A | |
| 32. |
Which of the following alkaline earth metal oxide is most basic?A. `BeO`B. `MgO`C. `CaO`D. `BaO` |
|
Answer» Correct Answer - D Basic strength increases down the group `(darr)`. |
|
| 33. |
Thermal decompositon of a compound `(X)` yields , a basic oxide `(Y)` and an acidic oxide `(Z)` simultanously. The acidic oxide `(Z)` can be absorbed by alkaline `KOH`. Indentify `(X),(Y)` and `(Z)`. |
|
Answer» `Xoverset(Delta)(rarr)underset("oxide")underset("Basic")(Y)+underset("oxide")underset("Acidic")(Z)` `underset((X))(CaCO_(3))overset(Delta)(rarr)underset((Y)0underset("basic oxide")(CaO)+underset((Z))underset("Acidic oxide")(CO_(2))` `underset((Z))(CO_(2))+KOHrarrK_(2)CO_(3)+H_(2)O` Hence `(X),(Y)` and `(Z)` are `CaCO_(3), CaO` and `CO_(2)` respectively. |
|
| 34. |
Berllium shows diagonal relationship withA. `Mg`B. `Na`C. `Al`D. `B` |
|
Answer» Correct Answer - C Due to same charge/radius ratio |
|
| 35. |
`Be` and `Al` exhibit many properties which are similar. But the two elements differ inA. Forming covalent bondsB. Forming polymeric hydridesC. Exhibiting maximum covalency in compoundsD. Exhibiting amphoteric nature in their oxides |
|
Answer» Correct Answer - C `Be` exhibits maximum coordination `4`, whereas `Al`, due to the presence of low lying `d-`orbital has coordination number `6`. |
|
| 36. |
`Be` and `Al` have the following resemblance due to diagonal relationship,A. Have nearly equal electronegativityB. Form amphoteric oxidesC. Have same charge/radius rationD. Both form dimeric halides |
| Answer» Correct Answer - A::B::C::D | |
| 37. |
Which of the following statements (s) is/are not true about the diagonal relationship of `Be` and `Al`?A. Their oxides are basicB. They become passive by conc `HNO_(3)`C. Both react with `NaOH` to liberate hydrogenD. Their carbides give acetlylene on hydrolysis |
|
Answer» Correct Answer - A::D Their oxides are amphoteric due to small size and high `IE` and on hydrolysis they give methane. |
|
| 38. |
Plaster of paris isA. `CaSO_(4).(1)/(2)H_(2)O`B. `CaSO_(4).2H_(2)O`C. `CaSO_(4).CaCO_(3)`D. `CaSO_(4).5H_(2)O` |
| Answer» Correct Answer - A | |
| 39. |
Plaster of paris on losing water and gaining water gives `A` and `b`. Identify `A` and `B`. |
|
Answer» Plaster fo paris is `CaSO_(4).(1)/(2)H_(2)O` On losing water, it forms `CaSO_(4)` `CaSO_(4).(1)/(2)H_(2)Orarrunderset((A)"Dead burn plaster")(CaSO_(4)+(1)/(2)H_(2)O)` On gaining water, it forms `CaSO_(4).(1)/(2)H_(2)O+(3)/(2)H_(2)Orarrunderset((B) "Gypsum")(CaSO_(4).2H_(2)O)` `(A)` and `(B)` are `CaSO_(4)` and `CaSO_(4).2H_(2)O` respectively. |
|
| 40. |
Dead burnt plaster is ______. |
| Answer» Correct Answer - `CaSO_(4)` | |
| 41. |
The difference of number of water molecules in gypsum and plaster of Pairs isA. `(5)/(1)`B. `2`C. `(1)/(2)`D. `1(1)/(2)` |
|
Answer» Correct Answer - D Gypsum is `CaSO_(4).2H_(2)O`, where plaster of lparis is `CaSO_(4).(1)/(2)H_(2)O`. |
|
| 42. |
Lithopone is a mixture ofA. `BaSo_(4) and BaS`B. `BaSO_(4) and ZnS`C. `BaO and ZnS`D. `BaCO_(3) and ZnO` |
| Answer» Correct Answer - B | |
| 43. |
Give the chemical formula of the following: a. Plaster of paris, b. Asbestos, c. Hydrolith, d. Lithopone, e. Gypsum, f. Marble, g. Anhydrite, h. Baryta water, i. Quicklime, j. Slaked lime, k. Magnesite, l. Kieserite, m. Epsom salt, n. Baryta, o. Beryl, p. Witherite, q. Celsestine, r. Fluorspar |
|
Answer» (a). Plaster of Paris:, `CaSO_(4).(1)/(2)H_(2)O` (b). Asbestos:, `CaMg_(3)(SiO_(4))_(2)` (c ). Hydrolith:, `CaH_(2)` (d). Lithopone:, `BaSO_(4)+ZnS` (e). Gypsum: `CaSO_(4).H_(2)O` (f). Marble: `CaCO_(3)` (g). Anhydrite: `CaSO_(4)` (h). Baryta water: `Ba(OH)_(2)` (i). Quicklime: `CaO` (j). Slaked lime: `Ca(OH)_(2)` (k). Magnesite: `MgCO_(3)` (l). Kieserte: `MgSO_(4).H_(2)O` (m). Epson salt: `MgSO_(4).7H_(2)O` (n). Baryta: `BaSO_(4)` (o). Beryl: `3BeO.Al_(2)O_(3).6SiO_(2)` (p). Witherite: `BaCO_(3)` (q). Celestine:, `SrSO_(4)` (r). Fluorspar:, `CaF_(2)` |
|
| 44. |
The chemical formula of plaster of paris is `CaSO_(4).2H_(2)O` |
|
Answer» Correct Answer - F Plaster of paris is `CaSO_(4).(1)/(2)H_(2)O` |
|
| 45. |
Assertion (A): Addtion of `nH_(4)OH` to an aqueous solution of `BaCl_(2)` in the presence of excess of `NH_(4)Cl` precipitates `Ba(OH)_(2)`. Reason (R ): `Ba(OH)_(2)` is insoluble in water.A. If both `(A)` and `(R )` are correct and `(R )` is the correct explanation of `(A)`.B. If both `(A)` and `(R )` are correct, but `(R )` is not the correct explanation of `(A)`.C. If `(A)` is correct, but `(R )` is incorrect.D. If `(A)` is incrrect, but `(R )` is correct. |
|
Answer» Correct Answer - D Correct assertion: Additon of `NH_(4)OH` to an aqueous solution of `BaCl_(2)` in the presece of excess of `NH_(4)Cl` does not precipitate `Ba(OH)_(2)`. |
|
| 46. |
Calcium carbide reacts with nitrogen and forms an important fertiliser, calcium cynamide. How much calcium cynamide is formed when `6.4 g` of calcium carbide is completely converted into cyanamide? |
|
Answer» Correct Answer - 8 `underset(40+(12xx2)=64g)(CaC_(2))+N_(2)rarrunderset(40+12+(14xx2)=80g)(CaCN_(2))+C` `implies(80)/(64)xx6.4=8` |
|
| 47. |
In chlorophyll, the metal present is ________. |
| Answer» Correct Answer - Magnesium | |
| 48. |
Ordinary black board chalk is made up of ________. |
| Answer» Correct Answer - Gypsum | |
| 49. |
Dolomite is mineral whose formula isA. `CaCO_(3)`B. `MgCO_(3)`C. `CaCO_(3)`D. `CaSO_(4).2H_(2)O` |
|
Answer» Correct Answer - C Dolomite is `CaCO_(3).MgCO_(3)` |
|
| 50. |
Dolotime is a mineral ofA. AluminiumB. MagnesiumC. CalciumD. Potassium |
|
Answer» Correct Answer - B::C Dolomite is `MgCO_(3).CaCO_(3)` |
|