Explore topic-wise InterviewSolutions in Current Affairs.

Vitamin E can be obtained from foods such as wheat germ, nuts, seeds, green leafy vegetables and oils like safflower oil.

(iii) to prevent rapid drying.

Synthetic antioxidant:

• Synthetic antioxidants are chemicals that are synthesized in the laboratory and used as a substitute for natural antioxidants. 
• They delay the onset of oxidant or slow down the rate of oxidation of foodstuff. 
• They are added as additives to increase the shelf life of packed foods. 
• Common structural units found in synthetic antioxidants are phenolic -OH group and tertiary butyl group. e.g. BHT, which is 3,5-di-tert-butyl-4- hydroxytoluene.

A chemical which interacts with biomolecules such as carbohydrates, lipids, proteins and nuclei acids and produces a biological response is called drug.

Chemical substances which are used to protect food against bacteria, fungi are called food preservatives

e.g., sodium benzoate, sodium metabisulphite.

(iv) bithional

(ii) Sodium rosinate

(ii) tranquilizer

a) b) aspirin
b) Antiseptics – These are chemicals which either kill or prevent the growth of microorganisms and are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces. These are not ingested like antibiotics.

e.g. dettol, iodine etc.

Antibiotics – These are drugs used to treat infections because oftheir lowtoxicity for humans and animals. These are chemical substances produced by microorganisms (bacteria, fungi and molds) that inhibit the growth or even destroy microorganisms. Some purely synthetic compounds have antibacterial activity. Therefore, now antibiotics are refered to as substances produced wholly or partly by chemical synthesis, which in low concentrations inhibits the growth ordestroys microorganisms by intervening in their metabolic processes,

e.g. penicillin, chloramphenicol etc.

Zinc blende - ZnS, Calamine- ZnCO₃, Zincite – ZnO.  

The E⁰ of Zn is lower than that of Cu thus Zn can displace Cu²⁺ ion from its solution. On other hand side to displace Zn from Zn²⁺ ion, we need a more reactive metal than it.  

Copper pyrites CuFeS₂, Malachite CuCO₃.Cu (OH)₂, Cuprite Cu₂O. 

Option : c. Free radical

Option : b. alkaline hydrolysis

When impure nickel is heated in a current of CO at 330 – 350 K, it forms volatile nickel tetracarbonyl leaving behind the impurities. The nickel tetracarbonyl thus obtained is then heated to a higher temperature (450 - 470 K), when it undergoes thermal decomposition to give pure nickel.

Most drugs, when taken in doses higher than recommended, may carry harmful effects and sometimes, may even lead to death. Hence, a doctor should always be consulted before taking any medicine.

Important ores of Zn: 

Zinc blende - ZnS, Calamine- ZnCO₃, and Zincite – ZnO. ZnS is commercially important ore of Zn. Various stages involved in the extraction of Zn from ZnS are as following:- 

(i) Concentration of ore: It is concentrated by Froth flotation process followed by gravity separation process. 

(ii) Roasting: The concentrated ore is roasted in presence of air. Following reactions take place:

2ZnS + 3O₂ → 2ZnO + 2SO₂ 

The mass obtained during roasting is porous and is called porous clinker. 

(iii) Reduction of ZnO to Zn:  ZnO is made into bricketts with coke and clay and heated a 1163 K. Zn formed distills off and is collected by rapid cooling of zinc vapours.

ZnO + C → Zn + CO 

Graphite rods act as anode, are attacked by oxygen to form CO₂ and so to be replace time to time. 

Alumina cannot be fused easily because of high melting point. Dissolving of alumina in cryolite furnishes Al³⁺ ions, which can be electrolyzed easily. 

(i), (iv)

(i) Ranitidine

(iv) Cimetidine

1. Antiseptics are the chemicals applied to the living tissues either to kill or prevent the growth of micro organisms. Example : dettol. 

2. Antioxidants are the compounds which retards the action of oxygen on food and reduces its rate of decomposition by oxidation. Example: BHA. 

3. Narcotic analgesics are the chemicals used for the relief of pst operative pain. Example – morphine

1. A polymer containing two or more different kinds of monomer units is called a co-polymer.

2. Co – polymers have properties quite different from the homopolymers. 

3. The structural units of co-polymers are derived from the different monomers may be present in regular, alternation or in random order or strings of several units of one kind may alternate with strings of another. 

4. For example, Buna – S, Buna – N, Nylon – 6,6 etc. Buna – S contains styrene and butadiene monomer units.

(d) ibuprofen

Aspirin is an anti inflamatory drug.

Antihistamines are drugs which either reduce or inhabit the action of histamine in the body thereby preventing allergy. Two important antihistamines are brompheniramine and terfenadine.

Mode of action: Histamines interact with the binding sites of receptor in the body to produce allergy. Antihistamines compete with histamines for these binding sites of receptor and thus do not allow histamine to produce allergy.

1. In this classification, the drugs are grouped based on the biological system that they target in the recepient. For example, the antibiotics streptomycin and erthyromycin inhibit the protein synthesis in bacteria and are classified in the same group. 

2. However their mode of action is different. Streptomycin inhibits the initiation of protein synthesis, while erythromycin prevents the incorporation of new amino acids to the protein.

(c) Nylon – 2 Nylon 6

(iv) Assertion is correct statement reason is wrong statement.

(i) The high energy to transform Cu(s) to Cu²⁺ (aq) is not balanced by its hydration enthalpy.

 (ii) Mn²⁺ has d⁵ configuration (stable half-filled configuration)

(iii) d⁵ to d³ occurs in case of Cr²⁺ to Cr³⁺ . More stable t³2g) while it change from d⁶ to d⁵ in case of fe²⁺ to fe^3+.

Nucellus tissue (megasporangium) present inside the ovule.

Microsporangium or pollen sac of anther.

Saccharomyces cerevisiae.

Leguminous plants possess root nodules where nitrogen is fixed by symbiotic nitrogen fixing bacteria Rhizobium whereas cereals do not possess nitrogen fixing bacteria in their root nodules, so, they cannot fertilise the soil.

The effluent is passed into a settling tank where the bacterial ‘flocs’ are allowed to sediment. This is called activated sludge. The sludge is pumped into anaerobic sludge digesters where they are anaerobically digested. During this digestion, bacteria produce biogas.

The activated sludge is pumped into large tanks called anaerobic sludge digesters. Here, bacteria which grow anaerobically digest the bacteria and the fungi in the sludge. During this digestion, bacteria produce a mixture of gases which form biogas. Biogas is made up of methane, hydrogen sulphide and carbon dioxide.

Aerobic and anaerobic bacteria or fungi exist in sewage water.

After the primary treatment of water, aerobic bacteria are added in aeration tanks. Growth of these bacteria reduces BOD as they consume organic matter. Anaerobic bacteria are added in anaerobic sludge digesters, where these digest the sludge and form biogas, etc.

(a) Aerobic microbes.

(b) The primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into it. This allows vigorous growth of useful aerobic microbes into flocs (masses of bacteria associated with fungal filaments to form mesh like structures). While growing, these microbes consume the major part of the organic matter in the effluent. This significantly reduces the BOD (biochemical oxygen demand) of the effluent. The sewage water is treated till the BOD is reduced. Once the BOD of sewage or waste water is reduced significantly, the effluent is then passed into a settling tank where the bacterial 'flocs' are allowed to sediment. This sediment is called activated sludge. A small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum. The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters. Here, other kinds of bacteria, which grow anaerobically, digest the bacteria and the fungi in the sludge. During this digestion, bacteria produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide. These gases form biogas and can be used as source of energy as it is inflammable. The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.

• Microbes naturally present in the sewage are employed in the secondary treatment of the sewage.

• The effluent from the primary treatment is passed into large aeration tanks.

• This allows the rapid growth of aerobic microbes into flocs which consume the organic matter of the sewage and reduces the BOD.

• Then the effluent is passed into a settling tank, where the flocs are allowed to sediment forming the activated sludge.

• Major parts of this activated sludge is pumped into anaerobic sludge digesters, where the anaerobic bacteria digest microbes in the activated sludge.

• During this digestion bacteria produce a mixture of gases like methane, hydrogen sulphide and carbon dioxide, which form the biogas and can be used as a source of energy. The effluent is generally released into rivers and streams.

(c) The process of absorption works

(a) no energy expenditure is required

Two uses of anti – transpirants:

1. Anti – transpirants reduce the enormous loss of water by transpiration in crop plants. 

2. Useful for seedling transplantations in nurseries.

The loss of excess of water in the form of vapour from various aerial parts of the plant is called transpiration.

(b) increase of dissolved solutes in the solution.

Solute potential, otherwise known as osmotic potential denotes the effect of dissolved solute on water potential. In pure water, the addition of solute reduces its free energy and lowers the water potential value from zero to negative. Thus the value of solute potential is always negative. In a solution at standard atmospheric pressure, water potential is always equal to solute potential (Ψ_w = Ψ_s ).

Osmotic potential is defined as the ratio between the number of solute particles and the number of solvent particles in a solution.

Anaerobic respiration carried out by microorganisms is called fermentation. The products of fermentation are lactic acid, ethyl alcohol and carbon dioxide.