The colour of hydrogen is –

1. Blue                           

2. Yellow

3. Orange                       

4. No colour

When substance A reacts with water, it produces a combustible gas B and a solution of substances 'C' in water. When another substance 'D' reacts with this solution of C, it produces the same gas 'B' on warming but 'D' can produce gas 'B' on reaction with dilute sulphuric acid at room temperature. 'A' imparts a deep golden yellow colour to a smokeless flame of a bunsen burner. A, B, C and D respectively are -

1. $\mathrm{Na},$ ${\mathrm{H}}_2,$ $\mathrm{NaOH},$ $\mathrm{Zn}$                              

2. $\mathrm{K},$ ${\mathrm{H}}_2,$ $\mathrm{KOH},$ $\mathrm{Al}$

3. $\mathrm{Ca},$ ${\mathrm{H}}_2,$ $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2,$ $\mathrm{Sn}$                           

4. ${\mathrm{CaC}}_2,$ ${\mathrm{C}}_2{\mathrm{H}}_2,$ $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2,$ $\mathrm{Fe}$

The incorrect statement among the following  regarding reaction of  ${\mathrm{H}}_2{\mathrm{O}}_2$ is -

1.  ${\mathrm{S}}^{-2}$ $\to$ $\mathrm{S}$ (acidic medium)

2.  $\mathrm{Pb}$ $\to$ ${\mathrm{PbSO}}_4$

3.  ${\mathrm{Fe}}^{3+}$ $\to$ ${\mathrm{Fe}}^{2+}$ (acidic medium)

4.  $\mathrm{KI}$ $\to$ ${\mathrm{I}}_2$

A compound that has both polar and non-polar bonds is  –

1. ${\mathrm{NH}}_4\mathrm{Cl}$                                    

2. $\mathrm{HCN}$

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

4. ${\mathrm{CH}}_4$

Ice melts at a temperature lower than its usual melting point when the pressure is increased. This is because-

1. Ice has less density than water

2. Pressure generates heat

3. The chemical bonds break under pressure

4. Ice is not a true solid

The oxidation states of the most electronegative element in the products of the reaction between ${\mathrm{BaO}}_2$ with dil. ${\mathrm{H}}_2{\mathrm{SO}}_4$ are–

1. 0, and –1                                   

2. –1, and –2

3. –2, and 0                                     

4. –2, and + 1

The correct statement among the following regarding hydrogen is–

1. It can form a bond in +1 as well as –1 oxidation state

2. It is always collected at the cathode

3. It has a very low ionization potential

4. It has the same electronegativity as halogens

The first ionization energy value $\left(\mathrm{kJ}\right)$ ${\mathrm{mol}}^{-1}$ for $\mathrm{H},$ $\mathrm{Li},$ $\mathrm{F},$ $\mathrm{and}$ $\mathrm{Na}$ 

is given below but not in a correct order

$1681,$ $520,$ $1312,$ $495.$

The ionization energy value of H would be -

1. 1681                                 

2. 1312

3. 520                                   

4. 485

The reaction of aqueous KMnO₄ with H₂O₂ in acidic condition gives:
1. $M{n}^{4+}$ $and$ $O_2$
2. $M{n}^{2+}$ $and$ $O_2$
3. $M{n}^{2+}$ $and$ $O_3$
4. $M{n}^{4+}$ $and$ $Mn{O}_2$

The method used to remove the temporary hardness of water is-

1. Synthetic resins method

2. Calgon's method

3. Clark's method

4. Ion-exchange method