Question
Read the passage given below and answer the following questions from 1 to 5.
Hydrogen Peroxide $(H_2O_2)$ Hydrogen peroxide is an important chemical used in pollution control treatment of domestic and industrial effluents.It can be prepared by the following methods.
i) Acidifying barium peroxide and removing excess water by evaporation under reduced pressure gives hydrogen.
$\text{BaO}_2.8\text{H}_2\text{O}(\text{s})+\text{H}_2\text{SO}_4\text{(aq)}\rightarrow\text{BaSO}_4\text{(s)}+\text{H}_2\text{O}_2\text{(aq)}+8\text{H}_2\text{O}\text{l}$
ii) Peroxodisulphate, obtained by electrolytic oxidation of acidified sulphate solutions at high current density, on hydrolysis yields hydrogen.
$2\text{HSO}_\bar{4}(\text{aq})\xrightarrow{\text{Electrolysis}}\text{HO}_3\text{SOOSO}_3\text{H}(\text{aq})\xrightarrow{\text{Hydrolysis}}2\text{HSO}_\bar{4}\text{(aq)}+2\text{H}^+\text{(aq)}+\text{H}_2\text{O}_2\text{aq}$
This method is now used for the laboratory preparation of $D_2O_{2.}$
_{$\text{K}_2\text{S}_2\text{O}_8(\text{s})+2\text{D}_2\text{O}\text{(l)}\rightarrow2\text{KDSO}_4(\text{aq})+\text{D}_2\text{O}_2\text{(l)}$}
iii) Industrially it is prepared by the auto- oxidation of 2-alklylanthraquinols. 2 ethylanthraquinol H O oxidised product.
In this case 1% $H_2O_2$ is formed. It is extracted with water and concentrated to $\sim30\%$ (by mass) by distillation under reduced pressure. It can be further concentrated to $\sim85\%$ by careful distillation under low pressure. The remaining water can be frozen out to obtain pure $H_2O_2$. Physical Properties of the pure state $H_2O_2$ is an almost colourless (very pale blue) liquid. Its important physical properties. $H_2O_2$ is miscible with water in all proportions and forms a hydrate $H_2O_2.$ $H_2O$ (mp 221K). A 30% solution of $H_2O_2$ is marketed as ‘100 volume’ hydrogen peroxide. It means that one millilitre of 30% $H_2O_2$ solution will give 100 mL of oxygen at STP. Commercially marketed sample is 10 V, which means that the sample contains 3% $H_2O_2$ . Structure Hydrogen peroxide has a non-planar structure.
$H_2O_2$ decomposes slowly on exposure to light.
$2\text{H}_2\text{O}_2\text{(l)}\rightarrow2\text{H}_2\text{O}(\text{l})+\text{O}_2\text{(g)}$
In the presence of metal surfaces or traces of alkali (present in glass containers), the above reaction is catalysed. It is, therefore, stored in wax-lined glass or plastic vessels in dark. Urea can be added as a stabiliser. It is kept away from dust because dust can induce explosive decomposition of the compound.
Its wide scale use has led to tremendous increase in the industrial production of $H_2O_2$. Some of the uses are listed below:
i) In daily life it is used as a hair bleach and as a mild disinfectant. As an antiseptic it is sold in the market as
ii) It is used to manufacture chemicals like sodium perborate and per – carbonate, which are used in high quality detergents.
iii) It is used in the synthesis of hydroquinone, tartaric acid and certain food products and pharmaceuticals (cephalosporin)
iv) It is employed in the industries as a bleaching agent for textiles, paper pulp, leather, oils, fats,
v) Nowadays it is also used in Environmental (Green) Chemistry. For example, in pollution control treatment of domestic and industrial effluents, oxidation of cyanides, restoration of aerobic conditions to sewage wastes,
Heavy water, $D_2O$ It is extensively used as a moderator in nuclear reactors and in exchange reactions for the study of reaction mechanisms. It can be prepared by exhaustive electrolysis of water or as a by-product in some fertilizer industries. It is used for the preparation of other deuterium compounds, for example:
Dihydrogen can be used as a fuel .Dihydrogen releases large quantities of heat on combustion. The data on energy released by combustion of fuels like dihydrogen, methane, LPG etc. are compared in terms of the same amounts in mole, mass and volume Hydrogen Economy is an alternative. The basic principle of hydrogen economy is the transportation and storage of energy in the form of liquid or gaseous dihydrogen. Advantage of hydrogen economy is that energy is transmitted in the form of dihydrogen and not as electric power. It is for the first time in the history of India that a pilot project using dihydrogen as fuel was launched in October 2005 for running automobiles. Initially 5% dihydrogen has been mixed in CNG for use in four-wheeler vehicles. The percentage of dihydrogen would be gradually increased to reach the optimum level. Nowadays, it is also used in fuel cells for generation of electric power. It is expected that economically viable and safe sources of dihydrogen will be identified in the years to come, for its usage as a common source of energy.
Hydrogen Peroxide $(H_2O_2)$ Hydrogen peroxide is an important chemical used in pollution control treatment of domestic and industrial effluents.It can be prepared by the following methods.
i) Acidifying barium peroxide and removing excess water by evaporation under reduced pressure gives hydrogen.
$\text{BaO}_2.8\text{H}_2\text{O}(\text{s})+\text{H}_2\text{SO}_4\text{(aq)}\rightarrow\text{BaSO}_4\text{(s)}+\text{H}_2\text{O}_2\text{(aq)}+8\text{H}_2\text{O}\text{l}$
ii) Peroxodisulphate, obtained by electrolytic oxidation of acidified sulphate solutions at high current density, on hydrolysis yields hydrogen.
$2\text{HSO}_\bar{4}(\text{aq})\xrightarrow{\text{Electrolysis}}\text{HO}_3\text{SOOSO}_3\text{H}(\text{aq})\xrightarrow{\text{Hydrolysis}}2\text{HSO}_\bar{4}\text{(aq)}+2\text{H}^+\text{(aq)}+\text{H}_2\text{O}_2\text{aq}$
This method is now used for the laboratory preparation of $D_2O_{2.}$
_{$\text{K}_2\text{S}_2\text{O}_8(\text{s})+2\text{D}_2\text{O}\text{(l)}\rightarrow2\text{KDSO}_4(\text{aq})+\text{D}_2\text{O}_2\text{(l)}$}
iii) Industrially it is prepared by the auto- oxidation of 2-alklylanthraquinols. 2 ethylanthraquinol H O oxidised product.
In this case 1% $H_2O_2$ is formed. It is extracted with water and concentrated to $\sim30\%$ (by mass) by distillation under reduced pressure. It can be further concentrated to $\sim85\%$ by careful distillation under low pressure. The remaining water can be frozen out to obtain pure $H_2O_2$. Physical Properties of the pure state $H_2O_2$ is an almost colourless (very pale blue) liquid. Its important physical properties. $H_2O_2$ is miscible with water in all proportions and forms a hydrate $H_2O_2.$ $H_2O$ (mp 221K). A 30% solution of $H_2O_2$ is marketed as ‘100 volume’ hydrogen peroxide. It means that one millilitre of 30% $H_2O_2$ solution will give 100 mL of oxygen at STP. Commercially marketed sample is 10 V, which means that the sample contains 3% $H_2O_2$ . Structure Hydrogen peroxide has a non-planar structure.
$H_2O_2$ decomposes slowly on exposure to light.
$2\text{H}_2\text{O}_2\text{(l)}\rightarrow2\text{H}_2\text{O}(\text{l})+\text{O}_2\text{(g)}$
In the presence of metal surfaces or traces of alkali (present in glass containers), the above reaction is catalysed. It is, therefore, stored in wax-lined glass or plastic vessels in dark. Urea can be added as a stabiliser. It is kept away from dust because dust can induce explosive decomposition of the compound.
Its wide scale use has led to tremendous increase in the industrial production of $H_2O_2$. Some of the uses are listed below:
i) In daily life it is used as a hair bleach and as a mild disinfectant. As an antiseptic it is sold in the market as
ii) It is used to manufacture chemicals like sodium perborate and per – carbonate, which are used in high quality detergents.
iii) It is used in the synthesis of hydroquinone, tartaric acid and certain food products and pharmaceuticals (cephalosporin)
iv) It is employed in the industries as a bleaching agent for textiles, paper pulp, leather, oils, fats,
v) Nowadays it is also used in Environmental (Green) Chemistry. For example, in pollution control treatment of domestic and industrial effluents, oxidation of cyanides, restoration of aerobic conditions to sewage wastes,
Heavy water, $D_2O$ It is extensively used as a moderator in nuclear reactors and in exchange reactions for the study of reaction mechanisms. It can be prepared by exhaustive electrolysis of water or as a by-product in some fertilizer industries. It is used for the preparation of other deuterium compounds, for example:
Dihydrogen can be used as a fuel .Dihydrogen releases large quantities of heat on combustion. The data on energy released by combustion of fuels like dihydrogen, methane, LPG etc. are compared in terms of the same amounts in mole, mass and volume Hydrogen Economy is an alternative. The basic principle of hydrogen economy is the transportation and storage of energy in the form of liquid or gaseous dihydrogen. Advantage of hydrogen economy is that energy is transmitted in the form of dihydrogen and not as electric power. It is for the first time in the history of India that a pilot project using dihydrogen as fuel was launched in October 2005 for running automobiles. Initially 5% dihydrogen has been mixed in CNG for use in four-wheeler vehicles. The percentage of dihydrogen would be gradually increased to reach the optimum level. Nowadays, it is also used in fuel cells for generation of electric power. It is expected that economically viable and safe sources of dihydrogen will be identified in the years to come, for its usage as a common source of energy.
- In India, a pilot project using dihydrogen as fuel was launched in… for running automobiles.
- October 2005
- May 2004
- August 2014
- February 2010
- Structure Hydrogen peroxide has a … structure.
- Bilateral
- Non-planar
- Planar
- Cubic
- One millilitre of 30% $H_2O_2$ solution will give … mL of oxygen at STP.
- 30
- 10
- 100
- 300
- …. is extensively used as a moderator in nuclear reactors and in exchange reactions for the study of reaction mechanisms.
- $H_2O_2$
- $T_2O$
- $H_2O$
- $D_2O$
- Colour of pure state $H_2O_2$ is ..
- Very Pale red
- Very Pale yellow
- Very Pale green
- Very Pale blue
For convenience, each of the above processes can be considered as two separate steps, one involving the loss of electrons and the other the gain of electrons. As an illustration, we may further elaborate one of these, say, the formation of sodium chloride. $2\text{Na}(\text{s})\rightarrow2\text{Na}^+\text{g}+2\bar{\text{e}}$ $\text{Cl}_2\text{g}+2\bar{\text{e}}\rightarrow2\text{C}\bar{\text{I}}\text{ (g)}$ Each of the above steps is called a half reaction, which explicitly shows involvement of electrons. Sum of the half reactions gives the overall reaction $2\text{Na}(\text{s})+\text{Cl}_2\text{(g)}\rightarrow2\text{Na}^+\text{CI}(\text{s})\text{ or } 2\text{NaCI}(\text{s})$ Above Reactions suggest that half reactions that involve loss of electrons are called oxidation reactions. Similarly, the half reactions that involve gain of electrons are called reduction reactions. To summarise, we may mention that Oxidation: Loss of electron(s) by any species. Reduction: Gain of electron(s) by any species. Oxidising agent: Acceptor of electron(s). Reducing agent: Donor of electron(s).