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

${\mathrm{H}}_2\mathrm{O}$ has higher boiling point than ${\mathrm{H}}_2\mathrm{S}$ because.

(1) ${\mathrm{H}}_2\mathrm{O}$ is a smaller molecule and hence more closely packed

(2) The bond angle in ${\mathrm{H}}_2\mathrm{O}$ is more than in ${\mathrm{H}}_2\mathrm{S}$ and hence the former molecules are more tightly packed

(3) Of intermolecular hydrogen bonding in liquid ${\mathrm{H}}_2\mathrm{O}$

(4) The latent heat of vaporisation is higher for ${\mathrm{H}}_2\mathrm{O}$ than for ${\mathrm{H}}_2\mathrm{S}$

${\mathrm{H}}_2{\mathrm{O}}_2$ 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

A compound among the following that has hydrogen in the atomic state is –

1. Metallic hydrides                           

2. Ionic hydrides

3. Molecular hydrides                       

4. Water

A substance gives off ${\mathrm{O}}_2$ when heated, turns an acid solution of $\mathrm{KI}$ violet, and reduces acidified ${\mathrm{KMnO}}_4$. The substance is –

1. ${\mathrm{SO}}_3$                            

2. ${\mathrm{KNO}}_3$

3. ${\mathrm{H}}_2{\mathrm{O}}_2$                          

4. All of the above