Objective Type Questions and Answers for Class 11 Chemistry Chapter 9 Hydrogen

(1) Hydrogen resembles halogens in many respects for which several factors are responsible. Of the following factors which one is most important in this respect?

[A] Its tendency to lose an electron to form a cation.

[B] Its tendency to gain a single electron in its valence shell to attain stable electronic configuration.

[C] Its low negative electron gain enthalpy value.

[D] Its small size.

Answer: Its tendency to gain a single electron in its valence shell to attain stable electronic configuration.

(2) Why does H⁺ ion always get associated with other atoms or molecules?

[A] Ionisation enthalpy of hydrogen resembles that of alkali metals.

[B] Its reactivity is similar to halogens.

[C] It resembles both alkali metals and halogens.

[D] Loss of an electron from hydrogen atom results in a nucleus of very small size as compared to other atoms or ions. Due to smal size it cannot exist free.

Answer: Loss of an electron from hydrogen atom results in a nucleus of very small size as compared to other atoms or ions. Due to smal size it cannot exist free.

(3) Metal hydrides are ionic, covalent or molecular in nature. Among LiH, NaH, KH, RbH, CsH, the correct order of increasing ionic character is

[A] LiH > NaH > CsH > KH>RbH

[B] LiH < NaH < KH < RbH < CsH

[C] RbH > CsH > NaH > KH > LiH

[D] NaH > CsH > RbH > LiH > KH

Answer: LiH < NaH < KH < RbH < CsH

(4) Which of the following hydrides is electron-precise hydride?

[A] B₂H₆

[B] NH₃

[C] H₂O

[D] CH₄

Answer: CH₄

(5) Radioactive elements emit α, β and γ rays and are characterised by their halflives. The radioactive isotope of hydrogen is

[A] Protium

[B] Deuterium

[C] Tritium

[D] Hydronium

Answer: Tritium

(6) Consider the reactions

(A) H₂O₂ + 2HI → I₂ + 2H₂O (B) HOCl + H₂O₂ → H₃O⁺ + Cl+ O₂

Which of the following statements is correct about H₂O₂ with reference to these reactions? Hydrogen perioxide is ________.

[A] an oxidising agent in both (A) and (B)

[B] an oxidising agent in (A) and reducing agent in (B)

[C] a reducing agent in (A) and oxidising agent in (B)

[D] a reducing agent in both (A) and (B)

Answer: an oxidising agent in (A) and reducing agent in (B)

(7) The oxide that gives H2O2 on treatment with dilute H2SO4 is —

[A] PbO2

[B] BaO2 .8H2O + O2

[C] MnO2

[D] TiO2

Answer: BaO2 .8H2O + O2

(8) Which of the following reactions increases production of dihydrogen from synthesis gas?

[A] (i)

[B] (ii)

[C] (iii)

[D] (iv)

Answer: (iii)

(9) When sodium peroxide is treated with dilute sulphuric acid, we get ______.

[A] sodium sulphate and water

[B] sodium sulphate and oxygen

[C] sodium sulphate, hydrogen and oxygen

[D] sodium sulphate and hydrogen peroxide

Answer: sodium sulphate and hydrogen peroxide

(10) Hydrogen peroxide is obtained by the electrolysis of ______.

[A] water

[B] sulphuric acid

[C] hydrochloric acid

[D] fused sodium peroxide

Answer: sulphuric acid

(11) Which of the following reactions is an example of use of water gas in the synthesis of other compounds?

[A] (i)

[B] (ii)

[C] (iii)

[D] (iv)

Answer: (iv)

(12) Which of the following ions will cause hardness in water sample?

[A] Ca²⁺

[B] Na⁺

[C] Cl^–

[D] K⁺

Answer: Ca²⁺

(13) Which of the following compounds is used for water softening?

[A] Ca₃(PO₄)₂

[B] Na₃PO₄

[C] Na₆P₆O₁₈

[D] Na₂HPO₄

Answer: Na₆P₆O₁₈

(14) Elements of which of the following group(s) of periodic table do not form hydrides.

[A] Groups 7, 8, 9

[B] Group 13

[C] Groups 15, 16, 17

[D] Group 14

Answer: Groups 7, 8, 9

(15) Only one element of ________ forms hydride.

[A] group 6

[B] group 7

[C] group 8

[D] group 9

Answer: group 6

(16) Which of the following statements are not true for hydrogen?

[A] It exists as diatomic molecule.

[B] It has one electron in the outermost shell.

[C] It can lose an electron to form a cation which can freely exist

[D] It forms a large number of ionic compounds by losing an electron.

Answer: C, D

(17) Dihydrogen can be prepared on commercial scale by different methods. In its preparation by the action of steam on hydrocarbons, a mixture of CO and H₂ gas is formed. It is known as

[A] Water gas

[B] Syngas

[C] Producer gas

[D] Industrial gas

Answer: A, B

(18) Which of the following statement(s) is/are correct in the case of heavy water?

[A] Heavy water is used as a moderator in nuclear reactor.

[B] Heavy water is more effective as solvent than ordinary water.

[C] Heavy water is more associated than ordinary water.

[D] Heavy water has lower boiling point than ordinary water.

Answer: A, C

(19) Which of the following statements about hydrogen are correct?

[A] Hydrogen has three isotopes of which protium is the most common.

[B] Hydrogen never acts as cation in ionic salts.

[C] Hydrogen ion, H+, exists freely in solution.

[D] Dihydrogen does not act as a reducing agent.

Answer: A, B

(20) Some of the properties of water are described below. Which of them 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 water is heavier than liquid water.

Answer: C, D

Objective Type Questions and Answers for Class 11 Chemistry Chapter 9 Hydrogen

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