In acidic medium, H₂O₂ changes ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$ to CrO₅ which has two (-O-O-) bonds. Oxidation state of Cr in CrO₅ is

(a) +5

(b) +3

(c) +6

(d) -10

Nascent hydrogen consists of $-$

(A) Hydrogen atoms with excess energy

(B) Hydrogen molecules with excess energy

(C) Hydrogen ions in the excited state

(D) Solvated protons

Maximum concentration of ortho-$H_2$ in ordinary hydrogen is:

(1) 75% ortho-$H_2$ + 25% para-$H_2$

(2) 25% ortho-$H_2$ + 75% para-$H_2$

(3) 50% ortho-$H_2$ + 50% para-$H_2$

(4) 99% para-$H_2$ + 1% ortho-$H_2$

Blackened oil planting can be restored into original form by the action of:

1. Chlorine

2. ${\mathrm{BaO}}_2$

3. ${\mathrm{H}}_2{\mathrm{O}}_2$

4. ${\mathrm{MnO}}_2$

Which of the following statement regarding ${\mathrm{H}}_2{\mathrm{O}}_2$ is wrong.

(1) It is stable in acid medium

(2) It acts as oxidising as well as reducing agent

(3) It has zero dipole moment

(4) Pure ${\mathrm{H}}_2{\mathrm{O}}_2$ is slightly acidic

${\mathrm{Why\; does\; H₂O\; have\; a\; higher\; boiling\; point\; than\; H₂S?}}_{}$

1.  ${\mathrm{H₂O\; molecules\; are\; smaller\; and\; hence\; more\; closely\; packed}}_{}$

2. H₂O has a larger bond angle than H₂S, leading to tighter packing

3.  Due to intermolecular hydrogen bonding in liquid H₂O

4.  H₂O has a higher latent heat of vaporisation than H₂S

${\mathrm{H}}_2{\mathrm{O}}_2$ acts as antiseptic due to its –

(A) Reducing property                           

(B) Oxidising property

(C) Bleaching property                           

(D) Acidic property

Which contains both polar and non-polar bonds –

(A) ${\mathrm{NH}}_4\mathrm{Cl}$                                    

(B) $\mathrm{HCN}$

(C) ${\mathrm{H}}_2{\mathrm{O}}_2$                                     

(D) ${\mathrm{CH}}_4$

Exhausted permutit does not contain  –

1. ${\mathrm{Na}}^{+}$ ion                                     

2. ${\mathrm{Mg}}^{2+}$ ion

3. ${\mathrm{Al}}^{3+}$ ion                                  

4. ${\mathrm{Si}}^{4+}$ ion

The best explanation for not placing hydrogen with the group of alkali metals or halogens is.

(1) Hydrogen can form compounds with all other elements

(2) Hydrogen is much lighter element than the alkali metals or the halogens

(3) The IE of hydrogen is too high for group of alkali metals but  low for halogen group

(4) None of these