A substance on heating gives oxygen and it turns acidified KI solution violet and reduces acidified ${\mathrm{KMnO}}_4$ solution. Hence, the substance is 

1. ${\mathrm{SO}}_2$

2. ${\mathrm{K}}_2{\mathrm{CrO}}_4$

3. ${\mathrm{H}}_2{\mathrm{O}}_2$

4. All of the above

Molarity of a solution of 1 liter $H_2{O}_2$ marked as 20 volume is-

1. 1.78

2. 3.57

3. 20

4. 0.20

Incorrect statement is

1. Hybridisation of oxygen for water in solid, liquid and gas phase is $s{p}^3$

2. Density of water is more than the density of ice

3. Boiling point of HF> Boiling point of $H_{2}O,$ as electronegativity of F>O

4. All of thhe above

Which of the following reaction involve in Bosch's process used for the manufacturing of $H_2$?

1. $C{H}_{3}OH\underset{catalyst}{\overset{400°C}{\to }} CO+2H_2$

2. $H_2+CO+H_{2}O\to C{O}_2+2H_2$

3. $3Fe+4H_{2}O\stackrel{}{\to F{e}_3 O_4 + }4H_2$

4. $C_2{H}_6\stackrel{Cracking}{\to }2C+3H_2$

Which of the following hydride does not give $H_2$ at anode on electrolysis in molten state?

1. $Sr{H}_2$

2. $Ba{H}_2$

3. $Mg{H}_2$

4. $Ca{H}_2$

$H_2{O}_2$ restores the colour of old lead paintings, blackend by the action of$H_{2}S$ gas, by

1. Oxidising $PbS{O}_3 to PbS{O}_4$

2. Converting $PbC{O}_3 to Pb$

3. By oxidising $PbS to PbS{O}_4$

4. Converting $Pb{O}_2 to Pb$

$C_{\left(s\right)}+H_2{O}_{\left(g\right)}\stackrel{1270K}{\to }\underbrace{C{O}_{\left(g\right)}+H_{2\left(g\right)}}$
$coal Syn gas$

The above process is known as

1. Coal gasification

2. Coal digestion

3. Syngas gasification

4. Water gasification 

Electrolysis of molten hydrolith produces

1. $H_2 gas at cathode$

2. $H_2 gas at anode$

3. $N_2 gas at cathode$

4. $N_2 gas at anode$

An element having valence shell electronic configuration $3d^{6}4s^2$ when reacts with hydrogen forms

1. Saline hydrides

2. Electron rich hydrides

3. Interstitial hydrides

4. No hydrides

Ionic hydrides on treatment with water evolve

1. $H_2$

2. $H_2{O}_2$

3. $H_{2}O$

4. $O_2$