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

1.  Its tendency to lose an electron to form a cation.

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

3.  Its low negative electron gain enthalpy value.

4.  Its small size.

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

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

1.  LiH > NaH > CsH > KH>RbH

2.  LiH < NaH < KH < RbH < CsH

3.  RbH > CsH > NaH > KH > LiH

4.  NaH > CsH > RbH > LiH > KH

Which of the following hydrides is electron-precise hydride?

1.  ${\mathrm{B}}_2{\mathrm{H}}_6$

2.  ${\mathrm{NH}}_3$

3.  ${\mathrm{H}}_2\mathrm{O}$

4.  ${\mathrm{CH}}_4$

Radioactive elements emit α, β, and γ rays and are characterized by their half-lives. The radioactive isotope of hydrogen is:

1. Protium

2. Deuterium

3. Tritium

4. Hydronium

Consider the reactions

$\left(\mathrm{A}\right) H_2{O}_2 + 2HI \to {\mathrm{I}}_2+2{\mathrm{H}}_2\mathrm{O} \left(\mathrm{B}\right) \mathrm{HOCl} + {\mathrm{H}}_2{\mathrm{O}}_2 \to {\mathrm{H}}_3{\mathrm{O}}^{+}{\mathrm{Cl}}^{-} + {\mathrm{O}}_2$

Which of the following statements is correct about ${\mathrm{H}}_2{\mathrm{O}}_2$ with reference to these reactions? Hydrogen perioxide is ________.

1.  An oxidising agent in both (A) and (B)

2.  An oxidising agent in (A) and reducing agent in (B)

3.  A reducing agent in (A) and oxidizing agent in (B)

4.  A reducing agent in both (A) and (B)

The oxide that gives ${\mathrm{H}}_2{\mathrm{O}}_2$ on treatment with dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$ is ____

1.  ${\mathrm{PbO}}_2$

2.  ${\mathrm{BaO}}_2.8{\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{MnO}}_2$

4.  ${\mathrm{TiO}}_2$

Which of the following equations depict the oxidising nature of ${\mathrm{H}}_2{\mathrm{O}}_2$?

1.  $2{{\mathrm{MnO}}_4}^{-} + 6{\mathrm{H}}^{+} + 5{\mathrm{H}}_2{\mathrm{O}}_2 \to 2{\mathrm{Mn}}^{2+} + 8{\mathrm{H}}_2\mathrm{O} + 5{\mathrm{O}}_2$

2.  $2{\mathrm{Fe}}^{3+} + 2{\mathrm{H}}^{+} + {\mathrm{H}}_2{\mathrm{O}}_2 \to 2{\mathrm{Fe}}^{2+} + 2{\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

3.  $2{\mathrm{I}}^{-} + 2{\mathrm{H}}^{+}+ {\mathrm{H}}_2{\mathrm{O}}_2 \to {\mathrm{I}}_2+2{\mathrm{H}}_2\mathrm{O}$

4.  ${\mathrm{KIO}}_4 + {\mathrm{H}}_2{\mathrm{O}}_2 \to {\mathrm{KIO}}_3+{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

Which of the following equation depicts reducing nature of ${\mathrm{H}}_2{\mathrm{O}}_2$?

1.  $2{\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]}^{4-} + 2{\mathrm{H}}^{+}+{\mathrm{H}}_2{\mathrm{O}}_2 \to 2{\left[\mathrm{Fe}\left({\mathrm{CN}}_6\right)\right]}^{3-} + 2{\mathrm{H}}_2\mathrm{O}$

2.  ${\mathrm{I}}_2+{\mathrm{H}}_2{\mathrm{O}}_2+2{\mathrm{OH}}^{-} \to 2{\mathrm{I}}^{-}+2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

3.  ${\mathrm{Mn}}^{2+}+{\mathrm{H}}_2{\mathrm{O}}_2 \to {\mathrm{Mn}}^{4+}+2{\mathrm{OH}}^{-}$

4.  $\mathrm{PbS} + 4{\mathrm{H}}_2{\mathrm{O}}_2 \to {\mathrm{PbSO}}_4 + 4{\mathrm{H}}_2\mathrm{O}$

Hydrogen peroxide is-.

1.  An oxidising agent

2.  A reducing agent

3.  Both an oxidising and a reducing agent

4.  Neither oxidising nor reducing agent