1333 + Interview Questions in HYDROGEN IN GENERAL AWARENESS Page 1 InterviewSolution

1.	When temporary hard water containing `Mg(HCO_(3))_(2)` is boiled, the ppt. formed is ofA. `MgCO_(3)`B. `MgO`C. `Mg(OH)_(2)`D. None of these
Answer» Correct Answer - c `Mg(OH)_(2)` is less soluble than `MgCO_(3)`. On boiling temporary hard water containing `Mg^(+2)` ions, the ppt. obtained is of `Mg(OH)_(2)` are not that of `MgCO_(3)`

Discussion

2.	Water is said to be permanently hard when it contains `:`A. Chloride and sulphates of `Mg` and `Ca`B. Bicarbonates of `Na` and `K`.C. Carbonates of `Na` and `K`D. Phosphate of `Na` and `K.`
Answer» Correct Answer - a a

Discussion

3.	Hydrogen gas is not liberated when the following metal is added to dil. `HCl :`A. `Mg`B. `Sn`C. `Ag`D. `Zn`
Answer» Correct Answer - c Silver does not reacts with dil. Or conc. `HCl`.

Discussion

4.	When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water, the sodium ions are are exchanged withA. `H^(+) ion`B. `Ca^(2+) ion`C. `SO_(4)^(2-) ion`D. `HO^(-) ion`
Answer» Correct Answer - B `underset("Sodium zeolite") (Na_(2)Z)+underset(" From hard water")(CaCl_(2))tounderset(" Calcium zeolite")(CaZ) +2NaCl`

Discussion

5.	When zeolite, which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions `(Na^(o+))` are exchanged withA. `OH^(-)` ionsB. `SO_(4)^(2-)`ionsC. `Ca^(2+)` ionsD. `H^(+)` ions
Answer» Correct Answer - C `underset(Zeolite)(Na_(2)Al_(2)Si_(2)O_(8)).xH_(2)O+Ca^(+2)rarr CaAl_(2)Si_(2)O_(8).XH_(2)O+2Na^(+)`

Discussion

6.	When zeolite, which is hydrated sodium aluminate silicate, is treated with hard water, the sodium ions are exchanged with:A. `Cl^(ɵ)`B. `SO_(4)^(ɵ)`C. `Ca^(2+)`D. `Mg^(2+)`
Answer» Correct Answer - C::D `Na^(o+)` ions will be replaced by cations only i.e, `Ca^(2+)` angle `Mg^(2+)`

Discussion

7.	When zeolite, which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions `(Na^(o+))` are exchanged withA. `H^(o+)` ionsB. `Ca^(2+)` ionsC. `SO_(4)^(2-)` ionsD. `overset(Theta)(O)H` ions
Answer» Correct Answer - B

Discussion

8.	When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water, the sodium ions are exchanged withA. `H^(+)`B. `Ca^(+2)`C. `OH`D. `SO_(4)^(2-)`
Answer» Correct Answer - B `Na_(2)Z`-sodium zeolite. `Na_(2)Z+" hard water"rarrCaZ" on "MgZ+Na^(+)` `Ca^(+)&Mg^(2+)`

Discussion

9.	One mole of calciium phosphide on reaction with excess water givesA. One mole of phospheneB. Two moles of phospheneC. Two moles of phospheneD. One mole of phosphene pentoxide
Answer» Correct Answer - C `underset((Cal. phosp hide 1 mol e ))(Ca_(3)P_(2)+6H_(2)O) rarr underset(phosphen e (2 mol es ))(2PH_(3))+3Ca(OH)_(2)`

Discussion

10.	When zeolite, which is hydrated sodium aluminate silicate, is treated with hard water, the sodium ions are exchanged with:A. `H^(+)`ionsB. `Ca^(2+)` ionsC. `Mg^(2+)` ionsD. Both `Ca^(2+)` and `Mg^(2+)`
Answer» Correct Answer - D Zeolite when treated with hard water exchange `Ca^(+2)` and `Mg^(+2)` ions `(` present in hard water `)` with `Na^(+)` ions.

Discussion

11.	Why is H2O2 a better oxidant than water?
Answer» H₂O₂ is easily reduced to form O and H₂O. H₂O₂ →H₂O+O.

11.

Why is H2O2 a better oxidant than water?

Answer»

H₂O₂ is easily reduced to form O and H₂O.

H₂O₂ →H₂O+O.

Discussion

12.	What do you mean by 100 volume of hydrogen peroxide.
Answer» It means that one milliliter of 30% H₂O₂ solution will give 100v of oxygen at STP.

Discussion

13.	For de colorization of 1 mole of acidified KMnO4 , the moles of H2O2 required is ……(a) \(\frac{1}{2}\)(b) \(\frac{3}{2}\)(c) \(\frac{5}{2}\)(d)\(\frac{7}{2}\)
Answer» (c) \(\frac{5}{2}\) 2MnO₄^- + 5H₂O_2(aq) + 6H⁺ → 2Mn²⁺ + 5O₂ + 8H₂O

13.

For de colorization of 1 mole of acidified KMnO4 , the moles of H2O2 required is ……(a) \(\frac{1}{2}\)(b) \(\frac{3}{2}\)(c) \(\frac{5}{2}\)(d)\(\frac{7}{2}\)

Answer»

(c) \(\frac{5}{2}\)

2MnO₄^- + 5H₂O_2(aq) + 6H⁺ → 2Mn²⁺ + 5O₂ + 8H₂O

Discussion

14.	In the following questions, a statement of Assertion (A) is given followed by a corresponding statement of Reason (R) just below it. Of the statements, mark the correct answer as –(A) If both assertion and reason are true, and reason is the true explanation of the assertion.(B) If both assertion and reason are true, but reason is not the true explanation of the assertion.(C) If assertion is true, but reason is false.(D) If both assertion and reason are false.Assertion (A).H2O2 liberates O2 when it reacts with acidified KMnO4 solution.Reason (R). KMnO4oxidisesH2O2 to O2.
Answer» (A) If both assertion and reason are true, and reason is the true explanation of the assertion.

Discussion

15.	Sea water can’t be used in boiler. Explain given chemical equations.
Answer» Sea water contains soluble salts of calcium and magnesium, which on boiling change to insoluble salts and get deposited as a crust on the inner sides of a boiler. This crust acts as a bad conductor of heat and prevent the flow of heat to water. A large quantity of fuel gets wasted. Chemical Reaction

Discussion

16.	How does H2O2 react with KMnO4 in acidic medium? Write four uses of H2O2.
Answer» 2KMnO₂ + 3H₂SO₄ + 5H₂O₂ → K2SO₄ + 2MnSO₄ + 8H₂O + 5O₂ Uses : (i) It is used as oxidizing agent, (ii) It is used as reducing agent. (iii) It is used as bleaching agent, (iv) It is used as rocket propellant.

16.

How does H2O2 react with KMnO4 in acidic medium? Write four uses of H2O2.

Answer»

2KMnO₂ + 3H₂SO₄ + 5H₂O₂ → K2SO₄ + 2MnSO₄ + 8H₂O + 5O₂

Uses :

(i) It is used as oxidizing agent,

(ii) It is used as reducing agent.

(iii) It is used as bleaching agent,

(iv) It is used as rocket propellant.

Discussion

17.	20 ml of solution having 0.2 g of impure H2O2 reacts with 0.316 of KMnO4 in acidic medium. Calculate (a) Purity of H2O2 (b) Volume of dry oxygen evolved at 0°C and 750 mm pressure.
Answer» 2MnO₄^-(aq) + 6H⁺(aq) + 5H₂O₂(aq) → 2Mn²⁺(aq) + 8H₂O(l) + 50(g) 158 x 2 g of KMnO₄ reacts with 34 × 5 g of H₂O₂ 0.316 g of KMnO₄ will react with \(\frac{170}{0.2}\) x 0.316 g of H₂O₂ = 0.169 g of H₂O₂ ⇒ Percentage purity of H₂O₂ = \(\frac{0.169}{0.2}\) x 100 = 85% Also 316 g of KMnO₄ at STP produces 5 × 22 L of O₂ ⇒ 0.316g of KMnO₄ at STP will produce \(\frac{5\times 22.4}{316}\) x 0.316 = 0.112 L of O₂ Conversion to 750 mm pressure 760 x 0.112 = x × 750x = 0.113 L

17.

20 ml of solution having 0.2 g of impure H2O2 reacts with 0.316 of KMnO4 in acidic medium. Calculate (a) Purity of H2O2 (b) Volume of dry oxygen evolved at 0°C and 750 mm pressure.

Answer»

2MnO₄^-(aq) + 6H⁺(aq) + 5H₂O₂(aq) → 2Mn²⁺(aq) + 8H₂O(l) + 50(g)

158 x 2 g of KMnO₄ reacts with 34 × 5 g of H₂O₂

0.316 g of KMnO₄ will react with \(\frac{170}{0.2}\) x 0.316 g of H₂O₂ = 0.169 g of H₂O₂

⇒ Percentage purity of H₂O₂ = \(\frac{0.169}{0.2}\) x 100 = 85%

Also 316 g of KMnO₄ at STP produces 5 × 22 L of O₂

⇒ 0.316g of KMnO₄ at STP will produce \(\frac{5\times 22.4}{316}\) x 0.316

= 0.112 L of O₂

Conversion to 750 mm pressure 760 x 0.112 = x × 750x = 0.113 L

Discussion

18.	Presence of which of the following compounds make water hard. `Na_(2)SO_(4),Ca(HCO_(3))_(2),MgCl_(2),Na_(2)CO_(3),CaSO_(4),KCl , NaHCO_(3),MgSO_(3),CaCl_(3)`
Answer» Correct Answer - 5 Five , i.e., `Ca(HCO_(3))_(2), MgCl_(2),CaSO_(4), MgSO_(4), CaCl_(2)`

Discussion

19.	Under what conditoin of temperature and pressur the formation of atomic hydrogen from molecular hydrogen will be favoured most ?A. High temperature and high pressureB. Low temperature and low pressureC. High temperature and low pressureD. Low temperature and high pressure
Answer» Correct Answer - D `H+Hoverset(rarr)larrH_(2)" "DeltaH=-ve` Favourable condition lower temp & higher pressure.

Discussion

20.	Plumbosolvency is a health hazard in the transporatatino ofA. hard water onlyB. soft water onlyC. Both (A) and (B)D. Water containing plum juice.
Answer» Correct Answer - B

Discussion

21.	In group 6, only one metal forms hydride. This metal isA. MoB. WC. CrD. Sg
Answer» Correct Answer - C Only chromium from group 6 forms CrH.

Discussion

22.	In aqueous solution, `H_(2)` will not reduce :A. `Fe^(3+)`B. `Cu^(2+)`C. `Ag^(+)`D. `Zn^(2+)`
Answer» Correct Answer - D

Discussion

23.	Hydrogen gas is not obtained when zinc reacts withA. Cold waterB. Dil. HClC. Dil. `H_(2)SO_(4)`D. Hot NaOH`(20%)`
Answer» Correct Answer - A

Discussion

24.	Hydrogen gas is not obtained when zinc reacts withA. cold waterB. dil `H_(2)SO_(4)`C. dil HClD. hot `20%` NaOH solution.
Answer» Correct Answer - A Zinc does not react with cold water.

Discussion

25.	Hydrogen is not obtained when zinc reacts withA. cold waterB. Hot NaOH solutionC. Conc. Sulphuric acidD. Dilute HCl
Answer» Correct Answer - A,B,D `Zn + H_(2)O rarr Zn(OH)_(2) + H_(2)` `Zn + NaOH rarr Na_(2)ZnO_(2) + H_(2)` `Zn + HCl rarr ZnCl_(2) + H_(2)` `Zn + "conc". H_(2)SO_(4) rarr ZnSO_(4) + SO_(2) + H_(2)O`

Discussion

26.	Statement-I: Pure zinc reacts slowly with sulphuric acid to produce hydrogen. Statement-II: Hydrogen produced initially forms and exteremely thin layer on zinc surface which prevents its dissolution in sulphuric acid.A. If both Statement-1 `&` Statement-II are True `&` the Statement-II is not a correct explanation of the Statement I.B. If both Statement-I `&` Statement-II are True but Statement-II is not a correct explanantion of the Statement-I.C. If Statement-I is True but the Statement-II is False.D. If Statement-I is False but the Statement-II is True.
Answer» Correct Answer - A

Discussion

27.	Assertion `(A)`: In a reaction of `H_2O_2` and `Na_2CO_3`, hydrogen peroxide acts as acid. Reason `(R)` : `H_2O_2` cannot act as acid.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 - C Reason (R) is wrong, `H_(2)O_(2)` acts as acid.

Discussion

28.	`H_2O_2` cannot act asA. oxidising agentB. dehydrating agentC. reducing agentD. acid
Answer» Correct Answer - B

Discussion

29.	Hydrogen is not obtained when zinc reacts withA. Cold waterB. Hot `NaOH` solutionC. Conc. Sulphuric acidD. dilute `HCl`
Answer» Correct Answer - c `Zn+H_(2)O rarr ZnO+H_(2)` `Zn+2NaOH rarr Na_(2)ZnO_(2)+H_(2)` `Zn+2H_(2)SO_(4) rarr ZnSO_(4)+SO_(4)+2H_(2)O` `Zn+2HClrarr ZnCl_(2) +H_(2)`

Discussion

30.	Water cannot act as `:`A. oxidantB. hydrolytic agentC. hydrogenating agentD. reductant
Answer» Correct Answer - c c

Discussion

31.	Some of the properties of water are described below. Which of them is/are not correct /A. Water is known to be a universal solventB. Hydrogen bonding is present to a large extent in liquid water.C. There is no hydrogen bonding in the frozen state of waterD. Frozen water is heavier than liquid water.
Answer» Correct Answer - C::D There is H-bonding even in frozen water , and frozen water , i.e., ice is lighter than liquid water.

Discussion

32.	Some of the properties of water are described below. Which of them is/are not correct?(i) Water is known to be a universal solvent.(ii) Hydrogen bonding is present to a large extent in liquid water.(iii) There is no hydrogen bonding in the frozen state of water.(iv) Frozen water is heavier than liquid water.
Answer» (iii) There is no hydrogen bonding in the frozen state of water. (iv) Frozen water is heavier than liquid water.

Discussion

33.	Some of the properties of water are described below. Which of the is /are not correct ?A. Water is known to be a universal solvent.B. Hydrogen bonding is present to a large extent in liquid water.C. There is no hydrogen bonding in the frozen state of water.D. Frozen wter is heavier than liquid water.
Answer» (c ) Hydrogen bonding is present in frozen water is ice. (d) Frozen water(ice) is lighter than liquid water.

Discussion

34.	Hardness of water may be tempoarary or permanent .Permanent hardness is due to the presence ofA. Chlorides of Ca and Mg in waterB. Sulphates of Ca and Mg is waterC. Hydrogen carbonates of Ca and Mg in water.D. Carbonates of alkali metals in water.
Answer» (a,b) Both the statements are correct.

Discussion

35.	Adsorbed hydrogen by Palladium is known asA. AtomicB. NascentC. OcculdedD. Heavy.
Answer» Correct Answer - C The process of adsorption of hydrogen on the surface of Palladium is called occlusion and the adsorbed hydrogen as occluded hydrogen.

Discussion

36.	The metal which reacts with cold water to produce hydrogen is1. magnesium2. aluminium3. calcium4. iron
Answer» The metal which reacts with cold water to produce hydrogen is calcium.

Discussion

37.	Out of hard water and soft water which would you like to use for washing of clothes and why?
Answer» Soft water because it does not contain salts of calcium and magnesium (which form a precipitate with soaps) and hence give more froth with soap solution.

Discussion

38.	Nascent hydrogen consists ofA. hydrogen ions in the excited stateB. hydrogen molecules with excess energyC. solvated protonsD. hydrogen atoms with excess energy
Answer» Correct Answer - D

Discussion

39.	Nascent hydrogen consists ofA. hydrogen atoms with excess energyB. hydrogen molecules with excess energyC. hydrogen ions in the excited stateD. solvated protons.
Answer» Correct Answer - B Hydrogen molecules with excess energy.

Discussion

40.	Assertion : Reducing power of Nascent hydrogen much greater then simple atomic hydrogen. Reason : Nascent hydrogen more above in electrochemical series than simple atomic-hydrogenA. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False.
Answer» Correct Answer - D

Discussion

41.	Asseriton : Hard Water is not fit for washing clothes. Reason : It contains `Ca^(+2) & Mg^(+2)` ion which can forms ppt with soap & detergents.A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False.
Answer» Correct Answer - A

Discussion

42.	Nascent hydrogen consists of:A. Hydrogen atoms with excess energyB. Hydrogen molecules with excess energyC. Hydrogen ions with in the excited stateD. Solvated protons
Answer» (a) Nascent hydroen [H] consists of hydrogen atoms with excess energy

Discussion

43.	Nascent hydrogen is prepared byA. `Na and C_(2)H_(5)OH`B. Al and NaOHC. Zn and dil. `H_(2)SO_(4)`D. All the three.
Answer» (d) All evolve nascent hydrogen

Discussion

44.	Hard water is not fit for washing clothes becauseA. it contains `Na_(2)SO_(4)` and `KCl`B. it gives precipitateC. it contains impuritiesD. it is acidic in nature
Answer» Correct Answer - B `{:(2RCOONa+Mg^(2+)tounderset("Insoluble")((RCOO)_(2))Mg+2Na^(o+)),(2RCOONa+Ca^(2+)tounderset("Insoluble")((RCOO)_(2))Ca+2Na^(o+)):}`

Discussion

45.	Heavy water is qualified as heavy liquid as it is.A. a heavy liquidB. an oxide of heavier isotope of oxygenC. an oxide of deuteriumD. denser than water
Answer» Correct Answer - C

Discussion

46.	Hydrogen can be placed in group `17` pf the periodic table becauseA. hydrogen forms hydrides like `NaH`B. hydrogen has isotopes `D` and `T`C. it is lightD. hydrogen combines with halogens
Answer» Correct Answer - D

Discussion

47.	Given colourless liquid will be determined whether it is water or not?A. by smellingB. by tastingC. by phenolphthaleinD. by adding a pinch of anhydrous `CuSO_(4)`
Answer» Correct Answer - C Water is odourless, tasteless and neutral and hence cannot be detected by smelling, testing or adding phenolphthalein. On adding a pinch of anhydrous `CuSO_(4)`(white) to water, hydrated copper sulphate is formed which is blue in colour. `underset(("White"))underset("Anhydrous")(CuSO_(4))+5H_(2)Otounderset("Blue")(CuSO_(4).5H_(2)O)`

Discussion

48.	Assertion `(A)`: Hydrogen oxidises lithium to `Li`. Reason `(R)` : Hydrogen cannot act as oxidising agent.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 - A Both (A) and (R) are correct and (R) is the correct explanation of (A).

Discussion

49.	In which of the following reaction dihydron acts as an oxidising agent?A. `Ca+H_(2)toCaH_(2)`B. `2H_(2)+O_(2)to2H_(2)O`C. `H_(2)+F_(2)to2HF`D. `CuO+H_(2)toCu+H_(2)O`
Answer» Correct Answer - A `overset((0))(Ca)+H_(2)tooverset((2+))(Ca)H_(2)`

Discussion

50.	Hydrogen peroxide is obtained by the electrolysis of _________.A. waterB. sulphuric acidC. hydrochloric acidD. fused sodium peroxide
Answer» Correct Answer - B `H_(2)O_(2)` is obtained by the electrolysis of a cold 50% solution of `H_(2)SO_(4)`. `2H_(2)SO_(4)to 2H^(+)+2HSO_(4)^(-)` `2HSO_(4)^(-)overset("Electrolysis")rarr underset(2HSO_(4(aq))^(-)+2H_((aq))^(+)+H_(2)O_(2(aq)))underset(darr" Hydrolysis")underset("Peroxodisulphate")(HO_(3)SOOSO_(3)H_((aq)))`

Discussion

Explore topic-wise InterviewSolutions in .

When temporary hard water containing `Mg(HCO_(3))_(2)` is boiled, the ppt. formed is ofA. `MgCO_(3)`B. `MgO`C. `Mg(OH)_(2)`D. None of these

Water is said to be permanently hard when it contains `:`A. Chloride and sulphates of `Mg` and `Ca`B. Bicarbonates of `Na` and `K`.C. Carbonates of `Na` and `K`D. Phosphate of `Na` and `K.`

Hydrogen gas is not liberated when the following metal is added to dil. `HCl :`A. `Mg`B. `Sn`C. `Ag`D. `Zn`

When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water, the sodium ions are are exchanged withA. `H^(+) ion`B. `Ca^(2+) ion`C. `SO_(4)^(2-) ion`D. `HO^(-) ion`

When zeolite, which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions `(Na^(o+))` are exchanged withA. `OH^(-)` ionsB. `SO_(4)^(2-)`ionsC. `Ca^(2+)` ionsD. `H^(+)` ions

When zeolite, which is hydrated sodium aluminate silicate, is treated with hard water, the sodium ions are exchanged with:A. `Cl^(ɵ)`B. `SO_(4)^(ɵ)`C. `Ca^(2+)`D. `Mg^(2+)`

When zeolite, which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions `(Na^(o+))` are exchanged withA. `H^(o+)` ionsB. `Ca^(2+)` ionsC. `SO_(4)^(2-)` ionsD. `overset(Theta)(O)H` ions

When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water, the sodium ions are exchanged withA. `H^(+)`B. `Ca^(+2)`C. `OH`D. `SO_(4)^(2-)`

One mole of calciium phosphide on reaction with excess water givesA. One mole of phospheneB. Two moles of phospheneC. Two moles of phospheneD. One mole of phosphene pentoxide

When zeolite, which is hydrated sodium aluminate silicate, is treated with hard water, the sodium ions are exchanged with:A. `H^(+)`ionsB. `Ca^(2+)` ionsC. `Mg^(2+)` ionsD. Both `Ca^(2+)` and `Mg^(2+)`

Why is H2O2 a better oxidant than water?

What do you mean by 100 volume of hydrogen peroxide.

For de colorization of 1 mole of acidified KMnO4 , the moles of H2O2 required is ……(a) \(\frac{1}{2}\)(b) \(\frac{3}{2}\)(c) \(\frac{5}{2}\)(d)\(\frac{7}{2}\)

Sea water can’t be used in boiler. Explain given chemical equations.

How does H2O2 react with KMnO4 in acidic medium? Write four uses of H2O2.

20 ml of solution having 0.2 g of impure H2O2 reacts with 0.316 of KMnO4 in acidic medium. Calculate (a) Purity of H2O2 (b) Volume of dry oxygen evolved at 0°C and 750 mm pressure.

Presence of which of the following compounds make water hard. `Na_(2)SO_(4),Ca(HCO_(3))_(2),MgCl_(2),Na_(2)CO_(3),CaSO_(4),KCl , NaHCO_(3),MgSO_(3),CaCl_(3)`

Under what conditoin of temperature and pressur the formation of atomic hydrogen from molecular hydrogen will be favoured most ?A. High temperature and high pressureB. Low temperature and low pressureC. High temperature and low pressureD. Low temperature and high pressure

Plumbosolvency is a health hazard in the transporatatino ofA. hard water onlyB. soft water onlyC. Both (A) and (B)D. Water containing plum juice.

In group 6, only one metal forms hydride. This metal isA. MoB. WC. CrD. Sg

In aqueous solution, `H_(2)` will not reduce :A. `Fe^(3+)`B. `Cu^(2+)`C. `Ag^(+)`D. `Zn^(2+)`

Hydrogen gas is not obtained when zinc reacts withA. Cold waterB. Dil. HClC. Dil. `H_(2)SO_(4)`D. Hot NaOH`(20%)`

Hydrogen gas is not obtained when zinc reacts withA. cold waterB. dil `H_(2)SO_(4)`C. dil HClD. hot `20%` NaOH solution.

Hydrogen is not obtained when zinc reacts withA. cold waterB. Hot NaOH solutionC. Conc. Sulphuric acidD. Dilute HCl

`H_2O_2` cannot act asA. oxidising agentB. dehydrating agentC. reducing agentD. acid

Hydrogen is not obtained when zinc reacts withA. Cold waterB. Hot `NaOH` solutionC. Conc. Sulphuric acidD. dilute `HCl`

Water cannot act as `:`A. oxidantB. hydrolytic agentC. hydrogenating agentD. reductant

Hardness of water may be tempoarary or permanent .Permanent hardness is due to the presence ofA. Chlorides of Ca and Mg in waterB. Sulphates of Ca and Mg is waterC. Hydrogen carbonates of Ca and Mg in water.D. Carbonates of alkali metals in water.

Adsorbed hydrogen by Palladium is known asA. AtomicB. NascentC. OcculdedD. Heavy.

The metal which reacts with cold water to produce hydrogen is1. magnesium2. aluminium3. calcium4. iron

Out of hard water and soft water which would you like to use for washing of clothes and why?

Nascent hydrogen consists ofA. hydrogen ions in the excited stateB. hydrogen molecules with excess energyC. solvated protonsD. hydrogen atoms with excess energy

Nascent hydrogen consists ofA. hydrogen atoms with excess energyB. hydrogen molecules with excess energyC. hydrogen ions in the excited stateD. solvated protons.

Nascent hydrogen consists of:A. Hydrogen atoms with excess energyB. Hydrogen molecules with excess energyC. Hydrogen ions with in the excited stateD. Solvated protons

Nascent hydrogen is prepared byA. `Na and C_(2)H_(5)OH`B. Al and NaOHC. Zn and dil. `H_(2)SO_(4)`D. All the three.

Hard water is not fit for washing clothes becauseA. it contains `Na_(2)SO_(4)` and `KCl`B. it gives precipitateC. it contains impuritiesD. it is acidic in nature

Heavy water is qualified as heavy liquid as it is.A. a heavy liquidB. an oxide of heavier isotope of oxygenC. an oxide of deuteriumD. denser than water

Hydrogen can be placed in group `17` pf the periodic table becauseA. hydrogen forms hydrides like `NaH`B. hydrogen has isotopes `D` and `T`C. it is lightD. hydrogen combines with halogens

Given colourless liquid will be determined whether it is water or not?A. by smellingB. by tastingC. by phenolphthaleinD. by adding a pinch of anhydrous `CuSO_(4)`

In which of the following reaction dihydron acts as an oxidising agent?A. `Ca+H_(2)toCaH_(2)`B. `2H_(2)+O_(2)to2H_(2)O`C. `H_(2)+F_(2)to2HF`D. `CuO+H_(2)toCu+H_(2)O`

Hydrogen peroxide is obtained by the electrolysis of _________.A. waterB. sulphuric acidC. hydrochloric acidD. fused sodium peroxide