திருவண்ணாமலை மாவட்டம் அரசு கலைக் கல்லூரியில் இரண்டாம் ஆண்டு படிக்கும் மாணவர்களுக்கு நடைபெற்றுக் கொண்டிருக்கும் மூன்றாம் பருவ செமஸ்டர் ஆன்லைன் தேர்வுகளுக்கான விடைகள்-வினாக்களுடன் வழங்குகின்றோம்.. மாணவர்கள் இதை படித்து பயன்பெற வேண்டுகிறோம்..
flotation process, in mineral treatment and mining, process for concentrating the metal-bearing mineral in an ore. Crude ore is ground to a fine powder and mixed with water, frothing reagents, and collecting reagents. When air is blown through the mixture, mineral particles cling to the bubbles, which rise to form a froth on the surface.
The waste material (gangue) settles to the bottom. The froth is skimmed off, and the water and chemicals are distilled or otherwise removed, leaving a clean concentrate. The process, also called the froth-flotation process, is used for a number of minerals, especially silver.
| No . | MINERAL | ORE |
|---|---|---|
| 1. | Minerals are the natural inorganic substance that exit in the earth’ crust |
Ores are the Minerals from which metal can be e extracted economically and conveniently. |
| 2. | They have definite crystallin sctructure | They have definite not crystallin sctructure |
| 3. | All Minnerals are not Ores | All Ores are not Minnerals |
| 4. | Example: Clay is the mineral of Aluminium. | Example: Bauxite and Cryolite are the ores of Aluminium. |
| 4. | Minnerals may or may not contain a good percentage of metals | Ore always contain a good percentage of metals |
fumaric acid? (மலோனிக் அமிலம் மற்றும் பியூமரிக் அமிலம்
வேறுபடுத்துக.)
விடை :
| No. | Malenic acid | Fumaric acid |
|---|---|---|
| 1. | Melenic acid is the cis-isomer of Butenedioc acid |
Fumaric acid is the trans-isomer of Butenedioc acid |
| 2. | Weak intramolucular hydrogen boning |
Strong intramolucular hydrogen boning |
| 3. | Much lower than that of fumaric acid |
Higher compared to malenic acid |
| 4. | via hydrolysis of malenic anhydride |
Via catalytic isomerization of melenic acid at low PH |
Geometrical isomerism is a type of stereoisomerism having the same molecular formula and same structure but differ in the relative arrangement of atoms.
There are 2 types of geometric isomers, ‘cis’ and ‘trans’. -cis isomers: when similar groups are present on the same side of the double bonds, then they are termed as cis. – trans isomers: when similar groups are present on the opposite sides of the double bonds then they are called trans isomers.
விடை :
They increase the rate of chemical reactions without themselves being consumed or permanently altered by the reaction. Second, they increase reaction rates without altering the chemical equilibrium between reactants and products.
* substrates bind to enzyme.
* enzyme undergoes conformational changes.
* substrates converted to products.
* products are released
விடை :
The second law of photochemistry, the Stark-Einstein law, states that for each photon of light absorbed by a chemical system, only one molecule is activated for subsequent reaction. This “photoequivalence law” was derived by Albert Einstein during his development of the quantum (photon) theory of light.
விடை :
Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to separate ions, unwanted molecules and larger particles from drinking water. Applying an external pressure to reverse the natural flow of pure solvent, thus, is reverse osmosis.
விடை :
The amount of time it takes to disintegrate by half an initial amount. For a given reaction, a reactant’s half-life t1/2 is the time it takes for its concentration to reach a value which is the arithmetic mean of its initial and final (equilibrium)
விடை :
* Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element’s atomic number on the Periodic Table. For example, carbon has six protons and is atomic number 6.
* Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon, the other two being XeF2 and XeF4.
Answer ALL questions.
A process of producing great heat and strong chemical reduction by oxidizing finely divided aluminum with oxygen taken from another metal, this metal being thus reduced from its oxide (as molten iron is obtained from iron oxide in welding by the Thermit process).
Hans Goldschmidt improved the aluminothermic process between 1893 and 1898, by igniting the mixture of fine metal oxide and aluminum powder by a Starter reaction without heating the mixture externally. The process was patented in 1898 and used extensively in the later years for rail track welding.
Some metal oxides cannot be reduced satisfactorily by carbon. So for them, aluminium which is more reactive metal is used. This process is called thermic process or alumino- thermic process. Therefore, aluminium is used in place of carbon and it acts as a reducing agent.
separation and magnetic separation. (ஈர்ப்பு பிரிப்பு மற்றும் புவி ஈர்ப்புப் பிரிப்பு முறையை வேறுபடுத்துக .)
condensation. ( வூர்ட்ஸ் எதிர்வினை மற்றும் டிக்மேன் ஒடுக்கம் விளக்குக. )
Claisen condensation is a type of coupling reaction in which a carbon-carbon bond forms between two esters or an ester and a carbonyl compound. Dieckmann condensation is a type of ring-forming reaction in which diesters react to give beta-keto esters.
The use of stronger bases, e.g. sodium amide or sodium hydride instead of sodium ethoxide, often increases the yield. The intramolecular version is known as Dieckmann Condensation.
Diesters can undergo an intramolecular reaction, called the Dieckmann condensation, to produce cyclic beta-keto esters. This reaction works best with 1,6-diesters, which produce five-membered rings, and 1,/-diesters which produce six membered rings.
The Claisen condensation is a carbon—carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base, resulting in a B-keto ester or a B-diketone.
(i) Inductive effect
(ii) Mesomeric effect
(iil) Steric effect. (பின்வருவனவற்றை விளக்குக.
1) தூண்டல் விளைவு
2) மீசோமெரிக் விளைவு
3)பஸ்டேரிக் விளைவு )
VSEPR theory is used to predict the arrangement of electron pairs around central atoms in molecules, especially simple and symmetric molecules. A central atom is defined in this theory as an atom which is bonded to two or more other atoms, while a terminal atom is bonded to only one other atom.
The main idea of VSEPR theory is that pairs of electrons (in bonds and in lone pairs) repel each other. The pairs of electrons (in bonds and in lone pairs) are called “groups”.
The VSEPR model predicts the 3-D shape of molecules and ions but is ineffective in providing any specific information regarding the bond length or the bond itself. … lt can predict the shape of nearly all compounds that have a central atom, as long as the central atom is not a metal
Some significant limitations of the VSEPR theory include: This theory fails to explain misoelectronic species (i.e. elements having the same number of electrons). The species may vary in shapes despite having the same number of electrons. The VSEPR theory does not shed any light on the compounds of transition metals.
applications. (ஒளிரும் விளைவு மற்றும் அதன் பண்புகளை
விளக்குக.)
Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacuum fluorescent displays, and cathode-ray tubes.
Advantages of Fluorescence :
Fluorescence is often used to analyze molecules, and the addition of a fluorescing agent with emissions in the blue region of the spectrum to detergents causes fabrics to appear whiter in sunlight. X-ray fluorescence is used to analyze minerals.
Fluorescence is the ability of certain chemicals to give off visible light after absorbing radiation which is not normally visible, such as ultraviolet light. … Fluorescence is the ability of certain chemicals to give off visible light after absorbing radiation which is not normally visible, such as ultraviolet light.
Fluorescence describes a phenomenon where light is emitted by an atom or molecule that has absorbed light or electromagnetic radiation from another source. In absorption, high energy light excites the system, promoting electrons within the molecule to transition from the ground state, to an excited state.
As it was already pointed, one of the most important advantages of this technique is due to its high sensitivity and specifity. Another is its fast and rapid diagnosis ability. The main disadvantage is that not all compounds fluoresce.
Fluorescence microscopy Is one of the most widely used tools in biological research. This is due to its high sensitivity, specificity (ability to specifically label molecules and structures of interest), and simplicity (compared to other microscopic techniques), and it can be applied to living cells and organisms.
(Or)
(b) Difference between the homogenous and
hetrogeneous catalyst. (ஒருபடித்தான மற்றும் பலபடித்தான
வினையூக்கியை வேறுபடுத்துக.)
fusion. (அணுக்கரு பிளவு மற்றும் அணுக்கரு இணைவை
விளக்குக. )
விடை :
nuclear fusion, process by which nuclear reactions between light elements form heavier elements (up to iron). In cases where the interacting nuclei belong to elementswith low atomic numbers (e.g., hydrogen [atomic number 1] or its isotopes deuterium and tritium), substantial amounts of energy are released.
Nuclear fission is a process by which the nucleus of an atom is split into two or more smaller nuclei, known as fission products. The fission of heavy elements is an exothermic reaction, and huge amounts of energy are released in the process.
Both fission and fusion are nuclear reactions that produce energy, but the processes are very different. Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.
USES OF NUCLEAR FISSION :
Uranium and plutonium are most commonly used for fission reactions in nuclear power reactors because they are easy to initiate and control. The energy released by fission in these reactors heats water into steam. The steam is used to spin a turbine to produce carbon-free electricity.
Naphthalene.
(ii) What is oxidation with reduction method
and uses?
Qi) நாப்தலின் உருவாக்கத்தை மற்றும் விவரிக்கவும் பண்புகளை விவரிக்கவும்.
(1) ஆக்ஸிஜனேற்ற ஒடுக்கு முறை மற்றும் பயன்கள் யாவை?
Answer any THREE questions.
கோபால்ட் மற்றும் டைட்டானியம் பிரித்தெடுத்தல் பற்றி
விரிவாக எழுதுக.
விடை :
HOW IS COBALT EXTRACTED ?
Extraction from sulfide ores is done using floatation, sulfide smelting to converter matte and later refining of the matte to recover cobalt. The extraction from lateritic ores is by leaching, sulfide precipitation, re-dissolution, cobalt solvent extraction and then electrowinning or hydrogen reduction.
Nickel-cobalt lateritic ores can be treated by either hydrometallurgical processes or pyrometallurgical processes, such as matte or ferronickel smelting, which require the entire ore to be melted and the metal values to be separated from the residual components of the ore.
There are no significant minerals of cobalt. It is rare and obtained mostly through refinin of nickel ore. It is used in superalloys for jet engines, chemicals magnets, and cemented carbides for cutting tools.
The Democratic Republic of the Congo has the largest cobalt reserves in the world, at some 3.6 million metric tons as of 2020. As the total global cobalt reserves amount to 7.1 million metric tons, this means that the DR Congo’s cobalt reserves account for nearly half of the world’s reserves of the metal.
Therefore, coke was used as the reducing agent and the carrier of adsorbing metal particles in the process of separation and roasting. Too much or too little coke is not conducive to the separation and extraction of cobalt.
Cobalt is an essential mineral used for batteries in electric cars, computers, and cell phones. More than /0 percent of the world’s cobalt is produced in the Democratic Republic of the Congo (DRC), and 15 to 30 percent of the Congolese cobalt is produced by artisanal and small-scale mining (ASM).
various types. (முப்பரிமாண மாற்றியம் மற்றும் அதன் வகை மற்றும்
எடுத்துக்காட்டு தருக. )
விடை :
Stereoisomers are molecules that have the same molecular formula and differ only in how their atoms are arranged in three-dimensional space. Be careful not to confuse them with constitutional isomers which also have the same molecular formula but differ in the way their atoms are connected.
To understand the fundamental difference between stereoisomers and constitutional isomers, imagine a neighborhood of new homes being built where each home uses exactly the same amount and type of building materials. Using those same building materials, the contractors can build a 1-story or a 2-story house. The 1-story and 2-story homes would be constitutional isomers –they differ in how the parts are connected. Now imagine two homes with the exact same floor plan that are mirror images of each other.
Builders sometimes do this because of the shape of the lots or because it gives the outward appearance of the homes being different when seen from the street. The two mirror image homes would be stereoisomers.
All isomers can be classified as either constitutional isomers or stereoisomers, and the stereoisomer category has several further subcategories as shown in the following classification chart. Let’s take a deeper look at the two main types of stereoisomers and a few real-world examples of each.
and half life period of 1* order reaction. (முதல் வகைவினை மற்றும் அரை ஆயுட்காலம் மூலம் முதல் வகைவினையை விளக்குக. )
(a) Osmosis.
(b) Osmotic Pressure.
(c) Reverse osmosis.
(d) Desalination.
type and examples. ( N- வகை மற்றும் P- வகை குறைகடத்திகளை பற்றி தகுந்த எடுத்துக்காட்டுடன் விரிவாக விளக்குக.)
விடை :
In general, there are two types of dopant atoms resulting in two types of extrinsic semiconductors. These dopants that produce the desired controlled changes are classified as either electron acceptors or donors and the corresponding doped semiconductors are known as:
* n-type Semiconductors.
* p-type Semiconductors.
Extrinsic semiconductors are components of many common electrical devices, as well of many detectors of ionizing radiation. For these purpose, a semiconductor diode (devices that allow current in only one direction) usually consists of p-type and n-type semiconductors placed in junction with one another.
n-type Semiconductors :
An extrinsic semiconductor which has been doped with electron donor atoms Is called an n-type semiconductor, because the majority of charge carriers in the crystal are negative electrons. Since silicon is a tetravalent element, the normal crystal structure contains 4 covalent bonds from four valence electrons.
EXAMPLES : Arsenic doped Silicon, Phosphorus doped Silicon, Arsenic doped Germanium, Phosphorus doped Germanium etc.
p-type Semiconductors
An extrinsic semiconductor which has been doped with electron acceptor atoms is called a p-type semiconductor, because the majority of charge carriers in the crystal are electron holes (positive charge carriers). The pure semiconductor silicon is a tetravalent element, the normal crystal structure contains 4 covalent bonds from four valence electrons.
EXAMPLES : Semiconductors like germanium or silicon doped with any of the trivalent atoms like boron, indium or gallium
The majority carriers in a p-type semiconductor are holes. In an n-type semiconductor, pentavalent impurity from the V group is added to the pure semiconductor. Examples of pentavalent impurities are Arsenic, Antimony, Bismuth etc. The pentavalent impurities provide extra electrons and are termed as donor atoms.