1333 + Interview Questions in HYDROGEN IN GENERAL AWARENESS Page 6 InterviewSolution

251.	Hydrogen behaves as a metalA. at low temperatureB. at high temperatureC. at low pressureD. at high pressure.
Answer» Correct Answer - D Hydrogen can behave as a metal at high pressure.

Discussion

252.	Fill in the blanks:(a) Hydrogen is...............than air.(b) Hydrogen is.................... soluble in water.(c) Hydrogen bums with a.............. flame and............... sound is heard.(d) A metal sodium hydrogen in the reactivity series gives hydrogen with............. (e) Hydrogen reacts with metal oxides to form...............and............... (f) Oxidation is the removal of hydrogen and addition of............ (g) In redox reaction oxidation and reduction occur................
Answer» (a) Hydrogen is lighter than air. (b) Hydrogen is sparingly soluble in water. (c) Hydrogen bums with an oxyhydrogen pale blue flame and pop sound is heard. (d) A metal sodium hydrogen in the reactivity series gives hydrogen with water. (e) Hydrogen reacts with metal oxides to form metal and water. (f) Oxidation is the removal of hydrogen and addition of oxygen. (g) In redox reaction oxidation and reduction occur simultaneously.

252.

Fill in the blanks:(a) Hydrogen is...............than air.(b) Hydrogen is.................... soluble in water.(c) Hydrogen bums with a.............. flame and............... sound is heard.(d) A metal sodium hydrogen in the reactivity series gives hydrogen with............. (e) Hydrogen reacts with metal oxides to form...............and............... (f) Oxidation is the removal of hydrogen and addition of............ (g) In redox reaction oxidation and reduction occur................

Answer»

(a) Hydrogen is lighter than air.

(b) Hydrogen is sparingly soluble in water.

(c) Hydrogen bums with an oxyhydrogen pale blue flame and pop sound is heard.

(d) A metal sodium hydrogen in the reactivity series gives hydrogen with water.

(e) Hydrogen reacts with metal oxides to form metal and water.

(f) Oxidation is the removal of hydrogen and addition of oxygen.

(g) In redox reaction oxidation and reduction occur simultaneously.

Discussion

253.	Which isotope of hydrogen has no neutron?
Answer» Correct Answer - protium.

Discussion

254.	The dielectric constant of `H_(2)O_(2)` is 80. The electrostatic force of attraction between `Na^(+)` and `Cl^(-)` will beA. reduced to `1//80` in water than in airB. reducted to `1//40` in water than in airC. will be increased to 80 in water than in airD. will remain unchanged.
Answer» Correct Answer - A Electrostatic forces of attraction are reduced to `1// 80th` in water.

Discussion

255.	Acidic order of following compounds is : (I) `H_(2)O_(2)," (II)" H_(2)O,` (III) `H_(2)," (IV)"D_(2)O`A. I gt II gt III gt IVB. II gt I gt IV gt IIIC. IV gt I gt II gt IIID. I gt II gt IV gt III
Answer» Correct Answer - D `H_(2)O_(2)gtH_(2)OgtD_(2)OgtH_(2)`

Discussion

256.	Calculate the strength of 5 volume `H_(2)O_(2)` solution.
Answer» By definiation , 5 volume `H_(2)O_(2)` solutions means that 1 L of 5 volume `H_(2)O_(2)` solution on decomposition produces 5 L of `O_(2)` at NTP. Consider the decompositon reaction, `2H_(2)O_(2) to 2H_(2)O + O_(2)` `2xx34g to 22.7 ` L at NTP Now 22.7 L `O_(2)` at NTP will be obtained from `H_(2)O_(2)` =68 g `therefore 5 `L of `O_(2)` at NTP will be obtained from `H_(2)O_(2)=(68xx5)/(22.7) g` `" "=14.98g =15g ` But 5 L of `O_(2)` at NTP is produced from 1 L of 5 volume `H_(2)O_(2)` `therefore` Strength of `H_(2)O_(2)` solution =` 15 g L^(-1)` or percentage strength of `H_(2)O_(2)` solution `=(15)/(1000)xx100=1.5%`

Discussion

257.	Which of the following statements is correct?(i) Hydrides of group 13 act as Lewis acids.(ii) Hydrides of group 14 are electron deficient hydrides.(iii) Hydrides of group 14 act as Lewis acids.(iv) Hydrides of group 15 act as Lewis bases.
Answer» (i) Hydrides of group 13 act as Lewis acids. (iv) Hydrides of group 15 act as Lewis bases.

257.

Which of the following statements is correct?(i) Hydrides of group 13 act as Lewis acids.(ii) Hydrides of group 14 are electron deficient hydrides.(iii) Hydrides of group 14 act as Lewis acids.(iv) Hydrides of group 15 act as Lewis bases.

Answer»

(i) Hydrides of group 13 act as Lewis acids.

(iv) Hydrides of group 15 act as Lewis bases.

Discussion

258.	Which class of covalent hydrides are considered as lewis acids?
Answer» Electron defient hydrides.

Discussion

259.	Assertion : Hydrides of group 13 elements are Lewis acids whereas hydrides of group 15-17 elements are Lewis bases. Reason : Group 13 hydrides have few electrons whereas group 15-17 hydrides have excess electrons which are present as lone pairs.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false.
Answer» Correct Answer - A

Discussion

260.	When `NaBH_(4)` is dissolved in waterA. it decomposes with the evolution of `H_(2)`B. `NA^(+)` and `BH_(4)^(-)` are formed which are stableC. `BH_(4)^(-)` ions formed initially decompose to produce `OH^(-)` ions, which prevent further decompositionD. NaH and `B_(2)H_(6)` are produced.
Answer» Correct Answer - C Factual question.

Discussion

261.	Which one of the following has minimum value of size of cation/anion ratio ?A. NaClB. KClC. `MgCl_2`D. `CaF_2`
Answer» Correct Answer - C The size of `Mg^(2+)` is minimum among `Na^+ , Ca^(2+), K^+` and `Mg^(2+)` and size of `Cl^-` is more than `F^-`, so the ratio of size of cation and anion are minimum in `MgCl_2`.

Discussion

262.	Compared with the alkaline earth metals, the alkali metals exhibitA. smaller ionic radiiB. higher boiling pointsC. greater hardnessD. lower ionisation energies
Answer» Correct Answer - D Alkali metals have the lowest ionisation enthalpy in each period because alkali metals are largest in their respective periods and therefore, the valency electrons are loosely held by the nucleus.

Discussion

263.	Which of the following is treated with chlorine to obtain bleaching powder?A. dilute solution of `Ca(OH)_2`B. concentrated solution of `Ca(OH)_2`C. dry CaOD. dry slaked lime
Answer» Correct Answer - D Bleaching powder is prepared by passing chlorine gas over dry slaked lime `Ca(OH)_2` by Hesenclaver method or by Bachmann method . `Ca(OH)_2+Cl_2 to CaOCl_2 + H_2O`

Discussion

264.	The correct order of mobility of alkali metal ions in aqueous solution isA. `Li^(+) gt Na^(+) gt K^(+) gt Rb^(+)`B. `Na^(+) gt K^(+) gt Rb^(+) gt Li^+`C. `K^(+) gt Rb^(+) gt Na^(+) gt Li^(+)`D. `Rb^(+) gt K^(+) gt Na^(+) gt Li^(+)`
Answer» Correct Answer - D The correct order of the mobility of the alkali metal ions in aqueous solution is `Rb^(+) gt K^(+) gt Na^(+) gt Li^(+)` due to following order of hydration energy of these ions `Li^(+) gt Na^(+) gt K^+ gt Rb^+` and as the hydration of ion increases, mobility decreases. Hydration enthalpy `prop 1/"Size of cation"`

Discussion

265.	Identify the correct statement.A. Gypsum is obtained by heating plaster of ParisB. Plastic of Paris can be obtained by hydration of gypsumC. Plaster of Paris is obtained by partial oxidation of gypsumD. Gypsum contains a lower percentage of calcium than plaster of Paris
Answer» Correct Answer - D The formula of gypsum is `CaSO_4. 2H_2O` and that of plaster of Paris is `(CaSO_4)_2 . 2H_2O`, so the percentage of Ca in plaster of Paris is more than gypsum.

Discussion

266.	Which one is the correct statement with reference to the solubility of `MgSO_4` in water ?A. `SO_4^(2-)` ions mainly contributes towards hydration energyB. Sizes of `Mg^(2+)` and `SO_4^(2-)` are similarC. Hydration energy of `MgSO_4` is higher in comparison to its lattice energyD. Ionic potential (charge/ radius ratio) of `Mg^(2+)` is very low
Answer» Correct Answer - C `MgSO_4` is soluble in water because it have hydration energy more than lattice energy . `Mg^(2+)` ions mainly contributes towards hydration enengy size of `SO_4^(2-)` ion is greation than `Mg^(2+)` ions.

Discussion

267.	Anhydrous BaO2 is not used for preparing H2O2. Why?
Answer» Anhydrous BaO₂ is not used because the BaSO₄ formed during the reaction forms a protective layer around unreacted BaO₂ and the reaction stops after some time.

Discussion

268.	Account for the following :(a) H3PO4 is preferred to H2SO4 in preparation of H2O2 from BaO2.8H2O (b) Water is responsible for moderation of the climate and the body temperature of living beings (c) Melting point of D2O is higher than normal water .
Answer» a) Because H₃PO₄ act as negative catalyst and prevent the decomposition of H₂O₂ b) Water has high heat of vapourisation and freezing due to hydrogen bond c) Deuterium is larger than hydrogen and hence strong hydrogen bonding

268.

Account for the following :(a) H3PO4 is preferred to H2SO4 in preparation of H2O2 from BaO2.8H2O (b) Water is responsible for moderation of the climate and the body temperature of living beings (c) Melting point of D2O is higher than normal water .

Answer»

a) Because H₃PO₄ act as negative catalyst and prevent the decomposition of H₂O₂

b) Water has high heat of vapourisation and freezing due to hydrogen bond

c) Deuterium is larger than hydrogen and hence strong hydrogen bonding

Discussion

269.	Heavy wateris compound of `:`A. hydrogen and heavier isotope of oxygen.B. heavier isotope of hydrogen and heavier isotope of oxygen.C. oxygen and heavier isotope of hydrogen.D. None of these
Answer» Correct Answer - C Heavy water is composed of heavy hydrogen `(` Deuterium `)` and oxygen the formula of heavy water is `.^(2)._(1)H_(2)O(D_(2)O).`

Discussion

270.	What type of water forms scum with soap?
Answer» Correct Answer - Hard water.

Discussion

271.	Assertion `(A)`: Colour of `KMnO_4` disappears when dihydrogen gas is bubbled through it. Reason `(R)` :Dihydrogen gas is highly inflammable.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 incorrect, but (R) is correct.
Answer» Correct Answer - B `KMnO_(4)+H_(2)to`No reaction

Discussion

272.	Assertion `(A)`: Dihydrogen is prepared in the laboratory by the action of conc `H_2SO_4` on granular zinc. Reason `(R)` : Pure hydrogen can be obtained by the action of water on sodium hydride.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 incorrect, but (R) is correct.
Answer» Correct Answer - D (A) is false, instead of conc. `H_(2)SO_(4)`, dil `H_(2)SO_(4)`, dil `H_(2)SO_(4)` is used.

Discussion

273.	Which position for hydrogen explain all its properties ?A. At the top of halogenB. At the top of alkali metalsC. At the top of carbon familyD. None of these
Answer» Correct Answer - d Position of hydrogen in the periodic table is not fully justified.

Discussion

274.	Which element on treatment with caustic soda solution produces `H_(2)` gas?A. ZnB. AlC. NaD. Ag
Answer» Correct Answer - B

Discussion

275.	Dihydrogen gas may be prepared by heating caustic soda onA. `Cu`B. `Zn`C. `Na`D. `Ag`
Answer» Correct Answer - B `Zn+2NaOHoverset(Delta)toNa_(2)ZnO_(2)+H_(2)`

Discussion

276.	The metal which displaces hydrogen from a boiling caustic soda solution is `:`A. AsB. ZnC. MgD. Fe.
Answer» Correct Answer - B Zn displaces hydrogen from the boiling solution of NaOH. `Zn+2NaOH+2H_(2)OtoNa_(2)[Zn(OH)_(4)]+H_(2)uarr`

Discussion

277.	Dihydrogen gas may be prepared by heating caustic soda onA. MgB. ZnC. FeD. Ag
Answer» Correct Answer - B

Discussion

278.	The metal which displaces hydrogen from a boiling caustic soda solution is `:`A. `Mg`B. `Fe`C. `As`D. `Zn`
Answer» Correct Answer - d `Zn +NaOH rarr underset(Sodium Zi ncate)rarr+H_(2) uarr`

Discussion

279.	Which one of the following is a ture peroxide ?A. `NO_(2)`B. `MnO_(2)`C. `BaO_(2)`D. `SO_(2)`.
Answer» Correct Answer - C

Discussion

280.	Which one of the following is manufactured in Haber’s process? (a) SO3 (b) NH3 (c) N2 (d) H2
Answer» Answer: (b) NH₃

Discussion

281.	Define the term Electron deficient.
Answer» The hydrides which do not have sufficient number of electrons to form normal covalent bonds is called electron deficient hydride. For example, hydride of group 13 (BH₃, AlH₃, etc.). They are known as Lewis acids i.e., electron acceptors. To make up their deficiency they generally exist in polymeric forms such as B₂H₆, Al₂H₆, etc.

281.

Define the term Electron deficient.

Answer»

The hydrides which do not have sufficient number of electrons to form normal covalent bonds is called electron deficient hydride.

For example, hydride of group 13 (BH₃, AlH₃, etc.). They are known as Lewis acids i.e., electron acceptors. To make up their deficiency they generally exist in polymeric forms such as B₂H₆, Al₂H₆, etc.

Discussion

282.	What are electron rich hydrides? Give examples.
Answer» They have excess electrons which are present as lone pairs . EX: NH₃, H₂O, HF

282.

What are electron rich hydrides? Give examples.

Answer»

They have excess electrons which are present as lone pairs .

EX: NH₃, H₂O, HF

Discussion

283.	Define the term Electron rich hydrides.
Answer» The hydrides which have excess electrons as required to form normal covalent bonds is called electron rich hydride. For example, hydrides of group 15 to 17 (NH₃, PH₃, H₂O, H₂S, H₂Se, H₂Te, HF etc.)

283.

Define the term Electron rich hydrides.

Answer»

The hydrides which have excess electrons as required to form normal covalent bonds is called electron rich hydride.

For example, hydrides of group 15 to 17 (NH₃, PH₃, H₂O, H₂S, H₂Se, H₂Te, HF etc.)

Discussion

284.	Which is used as moderator in nuclear reactor?A. `H_(2)O`B. AlumC. `D_(2)O`D. Any of these
Answer» (c ) `D_(2)O` (Heavy water) is used as moderator in nuclear reactor.

Discussion

285.	In the reaction `2H_(2)O_(2)rarr2H_(2)O+O_(2)` oxidation state of oxygen change as :A. Only - 1 to -2B. Only - 1 to zeroC. Both of the aboveD. `-1`to` -3`
Answer» Correct Answer - C Disproportionation reaction `2H_(2)underset(-1)(O_(2))rarr2H_(2)underset(-2)(O)+underset(0)(O_(2))`

Discussion

286.	Consider `LiH, MgH_2` and `CuH`:A. all are ionic hydridesB. `LiH,MgH_(2)` are ionic, whereas `CUH` is covalentC. all are covalentD. `LiH` is ionic, `MgH_(2)` is covalent `CuH` is metqallic
Answer» Correct Answer - D

Discussion

287.	Rohan heard that instructions wee given to the laboratory attendant to store a particular chemical i.e, keep it in the dark room, add some urea in it, and keep it away from dust. This chemical acts as an oxidising as well as reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and indusrtial effluents. (i) Write the name of this compound. (ii) Explain why such precautions are taken for storing this chemical.
Answer» (a) The name of the compound is `H_(2)O_(2)` . It acts as an oxidising as well as reducing agent in both acidic basic medium. (b) `H_(2)O_(2)` is decomposed by light and dust particles . Urea is added as a negative catalyst , i.e., to check its decomposition `2H_(2)O_(2)(aq) overset(hv)to 2H_(2)O (l) + O_(2)(g)` Because of the oxidising properties, `H_(2)O_(2)` is widely used to control pollution by oxidation of harmful cyanides and obnoxious smelling sulphides present in domestic adn industrial effluents . It also helps in sewage disposal by supplying `O_(2)` for oxidation of organic matter present in sewage waters.

Discussion

288.	The gas(es) used in the hydrogenation of oils in presence of nickel as a catalyst is/are:A. methaneB. ethaneC. ozoneD. hydrogen
Answer» Correct Answer - D

Discussion

289.	Which set of the metals do not have any effect on water?(a) Ag, Au, Pt (b) Na, Mg, Al (c) Fe, Ca, Zn (d) Fe, Pb, Na
Answer» (a) Ag, Au, Pt

Discussion

290.	Among `CaH_2, NH_3, NaH` and `B_2H_6` which are covalent hydrides?A. `NH_(3)` and `B_(2)H_(6)`B. `NaH` and `CaH`C. `NaH` and `NH_(3)`D. `CaH_(2)` and `B_(2)H_(6)`
Answer» Correct Answer - A `N` and `B` belong to `p-`block and since the electronegativity differences between these elements and `H` is very less, they form covalent hydrates.

Discussion

291.	The hydride ion `H^(-)` is a stronger base than its hydroxide ion `OH^(-)`. Which of the following reactions will occurs if sodium hydride (NaH) is dissolved in water ?A. `H^(-)(aq)+H_(2)OtoH_(3)O^(-)(aq)`B. `H^(-)(aq)+H_(2)O(l)toOH^(-)(aq)+H_(2)(g)`C. `H^(-)(aq)+H_(2)OC(l)to` No reactionD. None of these.
Answer» Correct Answer - B In this reaction `H^(-)` accepts `H^(+)` and as such acts as a base, `H_(2)O` gives `H^(+)` and as such acts as an acid.

Discussion

292.	Water is an ionic hydride.
Answer» Correct Answer - F False. `H_(2)O` is covalent hydride.

Discussion

293.	When electric current is passed through an ionic hydride in molten state:A. hydrogen is liberated at anodeB. hydrogen is liberated at cathodeC. hydride ion migrates towards cathodeD. hydride ion remains in solution
Answer» Correct Answer - A At anode: `2H^(ɵ)toH_(2)uarr+2e^(ɵ)`

Discussion

294.	The hydride ion `H^(ɵ)` is a stronger base than hydroxide ion. Which of the following reaction would occur if `NaH` is dissolved in waterA. `H_((aq))^(ɵ)+H_(2)O_((l))toH_(3)O^(o+)`B. `H_((aq))^(ɵ)+H_(2)O_((l))tooverset(Theta)(O)H_((aq))+H_(2)`C. `H^(ɵ)+H_(2)Oto`No reactionD. none of the above
Answer» Correct Answer - B

Discussion

295.	Hydrogen peroxide is a powerful oxidising agent, both in the acidic and alkaline medium. In acidic medium: `H_(2)O_(2)+2H^(o+)+2e^(ɵ)to2H_(2)O` In alkaline medium: `H_(2)O_(2)+2e^(ɵ)to2overset(Theta)(O)H` Hydrogen peroxide acts as a reducing agent towards powerful oxidising agents. In acidic medium: `H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)` In alkaline medium, however, its reducing nature is more effective. `H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)` In which of the following reactions, `H_2O_2` act as a reducing agent?A. `PbO_(2)(s)+H_(2)O_(2)(aq) rarr PbO(s)+H_(2)O(l)+O_(2)(g)`B. `Na_(2)SO_(3)(aq)+H_(2)O_(2)(aq)rarrNa_(2)SO_(4)(aq)+H_(2)O(l)`C. `2KI(aq)+H_(2)O_(2)(q)rarr 2 KOH(q)+I_(2)(s)`D. `KNO_(2)(aq)+H_(2)O_(2)(aq) rarr KNO_(3)(aq)+H_(2)O(l)`
Answer» Correct Answer - a In the following reaction, `H_(2)O_(2)` acts as a reducing agent. `PbO_(2)(s)+H_(2)O(aq) rarr PbO(s)+H_(2)O(l)+O_(2)(g)`

Discussion

296.	Hydrogen peroxide is a powerful oxidising agent, both in the acidic and alkaline medium. In acidic medium: `H_(2)O_(2)+2H^(o+)+2e^(ɵ)to2H_(2)O` In alkaline medium: `H_(2)O_(2)+2e^(ɵ)to2overset(Theta)(O)H` Hydrogen peroxide acts as a reducing agent towards powerful oxidising agents. In acidic medium: `H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)` In alkaline medium, however, its reducing nature is more effective. `H_(2)O_(2)to2H^(o+)+O_(2)+2e^(ɵ)` `H_2O_2` behaves as a bleaching agent due toA. oxidising natureB. reducing natureC. acidic natureD. unstable nature
Answer» Correct Answer - A

Discussion

297.	In the reaction of sodium hydride and water:A. sodium is reducedB. hydrogen is oxidisedC. hydrogen is reducedD. No element is oxidised or reduced
Answer» Correct Answer - B::C `NaH+H_(2)OtoNaOH+H_(2)`

Discussion

298.	In which of the following property hydrogen does not resemble with halogen:A. atomicityB. ionisation enthalpyC. reducing natureD. electropositive nature
Answer» Correct Answer - C::D

Discussion

299.	Hydrogen gas is liberated the action of aluminium with concentrated solution of______.
Answer» Correct Answer - sodium hydroxide Hydrogen gas is liberated the action of aluminium with concentrated solution of sodium hydroxide. `2Al+2NaOH+2H_(2)Oto2NaAlO_(2)+3H_(2)`

Discussion

300.	In laboratory preparation of H2O2 from hydrated barium peroxide with sulphuric acid , anhydrous barium peroxide is not used Why?
Answer» Because it forms a protective layer of barium sulphate over anhydrous barium peroxide.

Discussion

Explore topic-wise InterviewSolutions in .

Hydrogen behaves as a metalA. at low temperatureB. at high temperatureC. at low pressureD. at high pressure.

Which isotope of hydrogen has no neutron?

The dielectric constant of `H_(2)O_(2)` is 80. The electrostatic force of attraction between `Na^(+)` and `Cl^(-)` will beA. reduced to `1//80` in water than in airB. reducted to `1//40` in water than in airC. will be increased to 80 in water than in airD. will remain unchanged.

Acidic order of following compounds is : (I) `H_(2)O_(2)," (II)" H_(2)O,` (III) `H_(2)," (IV)"D_(2)O`A. I gt II gt III gt IVB. II gt I gt IV gt IIIC. IV gt I gt II gt IIID. I gt II gt IV gt III

Calculate the strength of 5 volume `H_(2)O_(2)` solution.

Which of the following statements is correct?(i) Hydrides of group 13 act as Lewis acids.(ii) Hydrides of group 14 are electron deficient hydrides.(iii) Hydrides of group 14 act as Lewis acids.(iv) Hydrides of group 15 act as Lewis bases.

Which class of covalent hydrides are considered as lewis acids?

When `NaBH_(4)` is dissolved in waterA. it decomposes with the evolution of `H_(2)`B. `NA^(+)` and `BH_(4)^(-)` are formed which are stableC. `BH_(4)^(-)` ions formed initially decompose to produce `OH^(-)` ions, which prevent further decompositionD. NaH and `B_(2)H_(6)` are produced.

Which one of the following has minimum value of size of cation/anion ratio ?A. NaClB. KClC. `MgCl_2`D. `CaF_2`

Compared with the alkaline earth metals, the alkali metals exhibitA. smaller ionic radiiB. higher boiling pointsC. greater hardnessD. lower ionisation energies

Which of the following is treated with chlorine to obtain bleaching powder?A. dilute solution of `Ca(OH)_2`B. concentrated solution of `Ca(OH)_2`C. dry CaOD. dry slaked lime

The correct order of mobility of alkali metal ions in aqueous solution isA. `Li^(+) gt Na^(+) gt K^(+) gt Rb^(+)`B. `Na^(+) gt K^(+) gt Rb^(+) gt Li^+`C. `K^(+) gt Rb^(+) gt Na^(+) gt Li^(+)`D. `Rb^(+) gt K^(+) gt Na^(+) gt Li^(+)`

Identify the correct statement.A. Gypsum is obtained by heating plaster of ParisB. Plastic of Paris can be obtained by hydration of gypsumC. Plaster of Paris is obtained by partial oxidation of gypsumD. Gypsum contains a lower percentage of calcium than plaster of Paris

Anhydrous BaO2 is not used for preparing H2O2. Why?

Account for the following :(a) H3PO4 is preferred to H2SO4 in preparation of H2O2 from BaO2.8H2O (b) Water is responsible for moderation of the climate and the body temperature of living beings (c) Melting point of D2O is higher than normal water .

Heavy wateris compound of `:`A. hydrogen and heavier isotope of oxygen.B. heavier isotope of hydrogen and heavier isotope of oxygen.C. oxygen and heavier isotope of hydrogen.D. None of these

What type of water forms scum with soap?

Which position for hydrogen explain all its properties ?A. At the top of halogenB. At the top of alkali metalsC. At the top of carbon familyD. None of these

Which element on treatment with caustic soda solution produces `H_(2)` gas?A. ZnB. AlC. NaD. Ag

Dihydrogen gas may be prepared by heating caustic soda onA. `Cu`B. `Zn`C. `Na`D. `Ag`

The metal which displaces hydrogen from a boiling caustic soda solution is `:`A. AsB. ZnC. MgD. Fe.

Dihydrogen gas may be prepared by heating caustic soda onA. MgB. ZnC. FeD. Ag

The metal which displaces hydrogen from a boiling caustic soda solution is `:`A. `Mg`B. `Fe`C. `As`D. `Zn`

Which one of the following is a ture peroxide ?A. `NO_(2)`B. `MnO_(2)`C. `BaO_(2)`D. `SO_(2)`.

Which one of the following is manufactured in Haber’s process? (a) SO3 (b) NH3 (c) N2 (d) H2

Define the term Electron deficient.

What are electron rich hydrides? Give examples.

Define the term Electron rich hydrides.

Which is used as moderator in nuclear reactor?A. `H_(2)O`B. AlumC. `D_(2)O`D. Any of these

In the reaction `2H_(2)O_(2)rarr2H_(2)O+O_(2)` oxidation state of oxygen change as :A. Only - 1 to -2B. Only - 1 to zeroC. Both of the aboveD. `-1`to` -3`

Consider `LiH, MgH_2` and `CuH`:A. all are ionic hydridesB. `LiH,MgH_(2)` are ionic, whereas `CUH` is covalentC. all are covalentD. `LiH` is ionic, `MgH_(2)` is covalent `CuH` is metqallic

The gas(es) used in the hydrogenation of oils in presence of nickel as a catalyst is/are:A. methaneB. ethaneC. ozoneD. hydrogen

Which set of the metals do not have any effect on water?(a) Ag, Au, Pt (b) Na, Mg, Al (c) Fe, Ca, Zn (d) Fe, Pb, Na

Among `CaH_2, NH_3, NaH` and `B_2H_6` which are covalent hydrides?A. `NH_(3)` and `B_(2)H_(6)`B. `NaH` and `CaH`C. `NaH` and `NH_(3)`D. `CaH_(2)` and `B_(2)H_(6)`

Water is an ionic hydride.

When electric current is passed through an ionic hydride in molten state:A. hydrogen is liberated at anodeB. hydrogen is liberated at cathodeC. hydride ion migrates towards cathodeD. hydride ion remains in solution

The hydride ion `H^(ɵ)` is a stronger base than hydroxide ion. Which of the following reaction would occur if `NaH` is dissolved in waterA. `H_((aq))^(ɵ)+H_(2)O_((l))toH_(3)O^(o+)`B. `H_((aq))^(ɵ)+H_(2)O_((l))tooverset(Theta)(O)H_((aq))+H_(2)`C. `H^(ɵ)+H_(2)Oto`No reactionD. none of the above

In the reaction of sodium hydride and water:A. sodium is reducedB. hydrogen is oxidisedC. hydrogen is reducedD. No element is oxidised or reduced

In which of the following property hydrogen does not resemble with halogen:A. atomicityB. ionisation enthalpyC. reducing natureD. electropositive nature

Hydrogen gas is liberated the action of aluminium with concentrated solution of______.

In laboratory preparation of H2O2 from hydrated barium peroxide with sulphuric acid , anhydrous barium peroxide is not used Why?