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 too low for halogen group

4. None of these

The colour of hydrogen is –

1. Blue                           

2. Yellow

3. Orange                       

4. No colour

In which of the following compounds, hydrogen exists in the atomic state –

1. Metallic hydrides                           

2. Ionic hydrides

3. Molecular hydrides                       

4. Water

${}_1{}^2\mathrm{H}$ stands for –

(1) Protium                               

(2) Heavy water

(3) Deuterium                           

(4) Tritium

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 these

100 ml of a sample of hard water required 25.1 ml of 0.02 (N) ${\mathrm{H}}_2{\mathrm{SO}}_4$ for complete reaction. What is the hardness of the given water sample ? (sp. gravity of given water sample = 1 gm/ml)

(A) 200 ppm                                 

(B) 250 ppm

(C) 251 ppm                                 

(D) 258 ppm

A mixture of hydrazine $\left({\mathrm{N}}_2{\mathrm{H}}_4\right)$ and $58-60\%$ solution of ${\mathrm{H}}_2{\mathrm{O}}_2$ is used as.

(1) Antiseptic                     

(2) Fertilizer

(3) Rocket fuel                   

(4) None

50 lit of hard water of 120 ppm temporary hardness is mixed with 1.62 kg of $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2,$ what is the hardness of the resulting water ? (The sp. gr. of hard water = 1 gm/ml)

(A) 8.088 × 10⁵ ppm                               

(B) 8.088 × 10⁴ ppm

(C) 80 ppm                                             

(D) 808 ppm

Commercially ${\mathrm{H}}_2{\mathrm{O}}_2$ is now prepared by –

(A) Action of ${\mathrm{H}}_2{\mathrm{SO}}_4$ on barium peroxide

(B) Action of ${\mathrm{H}}_2{\mathrm{SO}}_4$ on sodium peroxide

(C) Electrolysis of ${\mathrm{H}}_2{\mathrm{SO}}_4$

(D) By burning hydrogen in excess of oxygen

A sample of hard water was found to contain 68 ppm of ${\mathrm{CaSO}}_4$ and 19 ppm of ${\mathrm{MgCl}}_2$. Its total hardness is –

(1) 70 ppm                             

(2) 50 ppm

(3) 20 ppm                             

(4) 100 ppm