ANTON NEET

ANTON EDUCATION JOIN CLASSES FOR IAS, MPPSC XI, XII, IIT-JEE, NEET,

1. Floridean starch is found in

(a) Chlorophyceae
(b) Rhodophyceae
(c) Phaeophyceae
(d) Cyanophyceae

2.Peat moss is another name of

(a) Sphagnum
(b) Marchantia
(c) Riccia
(d) Dryopteris

3. Pteridophytes differ from mosses/bryophytes in possessing

(a) independent gametophyte
(b) well developed vascular system
(c) archegonia structure
(d) flagellate spermatozoids

4.Most plants are green in colour because

(a) the atmosphere filters out all the colours of the visible light spectrum except green.

(b) green light is the most effective wavelength region of the visible spectrum in sunlight for photosynthesis.

(c) chlorophyli is least effective in absorbing green light.

(d) green light allows maximum photosynthesis.

5. In Chlorophyceae, sexual reproduction occurs by

(a) isogamy and anisogamy
(b) isogamy, anisogamy and oogamy
(c) oogamy only
(d) anisogamy and oogamy

CONTROL OF WATER POLLUTION

1. Treatment of waste water.

The sewage is taken to sewage treatment sites. In this, industrial and municipal waste waters are treated in Effluent Treatment Plant (ETP) before their discharge in water bodies. In ETP waste water is given following treatments:

(a) Primary treatment.

In this method mechanical
screening and sedimentation of undissolved solids in raw sewage (e.g. large lumps of organic matter, sand and silt) is done. It fails to remove any dissolved substance in water. It does not remove the pathogens.

(b) Secondary treatment.

Sewage treated in primary treatment is brought in contact with oxygen and aerobic micro-organisms. They breakdown the organic matter into harmless materials as CO₂ and H₂O. Further, chlorination is done to kill the bacteria. It may be further treated to tertiary level.

Two measures are adopted for secondary treatment :

(i) Trickling filter method.
In this case, sewage water passes through a thick bed of gravel stones so that bacteria consume most of the organic matter.

(ii) Activated sludge method. In this, sewage water is pumped into an aeration tank which contains sludge (consisting of bacteria and algae). The bacteria are able to decompose most of the organic matter while algae provide oxygen to these decomposers. But the water still carries large amounts of nitrates, phosphates, etc.

(c) Advanced waste management or tertiary treatment. In this, salts like nitrates and phosphates are removed by precipitation technique. Water is now pure enough to drink.

2. Recycling of wastes. Gobar gas plant can be used for prevention and control of water pollution and to recycle the various kinds of waste products. Some other recommended methods are:

(a) Composting kills most of the pathogens and also ripens the dung into manure.

(b) From jute wastes, hardboard can be prepared.

(c) Coconut and other agricultural wastes can be used for the manufacture of paper and board.

3. Controlled use of pesticides and fertilizers.

Minimum amounts of pesticides should be applied so that no surplus remains in the soil. Only less stable compounds should be used in manufacturing biocides.

4. Reverse osmosis. By this technique, brackish water is demineralised by pumping it through a semipermeable membrane under strong pressure.

5. Thermal pollution can be checked by employing heat or dry cooling towers.

6. Water hyacinth removes biological and chemical pollutants. It also removes heavy metals like Cd, Hg, Pb and Ni.

Gibbs energy, also known as Gibbs free energy or Gibbs function, is a thermodynamic quantity used in chemistry to determine the spontaneity and equilibrium of a chemical reaction. It is denoted by the symbol "G" and named after the American scientist Josiah Willard Gibbs.

The Gibbs energy is defined as the difference between the enthalpy (H) and the product of the absolute temperature (T) and the entropy (S):

G = H - T * S

where:
- G is the Gibbs energy (in joules or other energy units),
- H is the enthalpy (in joules or other energy units),
- T is the temperature (in Kelvin),
- S is the entropy (in joules per Kelvin or other entropy units).

The Gibbs energy provides information about the maximum useful work that can be obtained from a system at constant temperature and pressure. It is particularly useful in determining whether a chemical reaction is spontaneous (i.e., if it will occur without external intervention) and in predicting the direction in which a reaction will proceed to reach equilibrium.

The sign of the Gibbs energy change (∆G) determines the spontaneity of a reaction:
- If ∆G is negative (∆G < 0), the reaction is spontaneous in the forward direction, and the system will tend to move towards equilibrium.
- If ∆G is positive (∆G > 0), the reaction is non-spontaneous in the forward direction, and external work is required to drive the reaction.
- If ∆G is zero (∆G = 0), the system is at equilibrium, and the reaction is reversible.

The Gibbs energy is also related to the equilibrium constant (K) of a reaction through the equation:

∆G = -RT * ln(K)

where:
- R is the gas constant (8.314 J/(mol·K)),
- T is the temperature (in Kelvin),
- ln denotes the natural logarithm.

This equation is known as the Gibbs free energy equation or the Gibbs-Helmholtz equation and provides a direct relationship between the Gibbs energy and the equilibrium constant of a reaction.

In summary, the Gibbs energy is a fundamental concept in thermodynamics that helps us understand the spontaneity and direction of chemical reactions and provides valuable insights into the equilibrium state of a system.

Fehling's reagent
Organic Chemistry

Grignard reagents

Organic Chemistry

Clemmensen reaction

Propanone to Propene
NEET/IIT
ORGANIC CHEMISTRY