Monday, 19 February 2018

TOP interview Question and Answer for B.sc Chemistry Fresher




 Trimethylamine Is A Pyramidal Molecule. What Is The Hybridization At Nitrogen?
Answer :
The nitrogen is bonded to three CH3 groups and has a lone pair, so the hybridisation is sp3.
 How Many Stereoisomers Of Phenylpropylene Oxide Are There?
Answer :
Two positional isomer A and B & two Stereoisomer of each so, total 4 isomers.
   Which One Of The Following Is Not Aromatic? 1)cyclotetrane 2)benzene 3)napthalene 4)anthracene ?
Answer :
cyclotetrane, because of the double bonds are not conjugation
   Number Of Sigma Bonds Present In Benzene Are Same As ..?
Answer :
Number of Sigma bonds present in Benzene are same as Borazine (inorganic Benzene).
no. of sigma bonds in Benzene= 12 (C6H6)
no. of sigma bonds in Borazine= 12 (B3N3H6)
  The Name Benzene Was Proposed By?
Answer :
Kekule
 Which Is Useful In The Manufacture Of Insectisides?
Answer :
Rotenone, Azadirachtin are natural insecticides, synthetic routes are deveoped recently.
DDT, Gammaxene were used but were scraped out as they pose health hazards and are insects are able sustain the max. dosages every year. Generally, Semio-chemicals, a class of compounds found in insects themselves are being studied and used as effective insecticides and warfare agents.
  What Are The 4 Classes Of Unsaturated Fatty Acids?
Answer :
o    Monounsaturated fat: This is a type of fat found in a variety of foods and oils.
o    Polyunsaturated fat: This is a type of fat found in plant-based foods and oils.They can be divided into two groups known as omega-3 fats and omega-6 fats. 
o    Omega-3 fatty acids: One type of polyunsaturated fat made up of mainly omega-3 fatty acids and may be beneficial to heart.
o    Omega-6 fats decrease risk of heart disease when they are consumed in place of saturated and trans fats.
   What Is The Difference Between Coordinate Covalent Bond And Covalent Bond?
Answer :
IN coordinate covalent bond electrons which are shared by both the atoms are comtributed by only one atom . This is otherwise known as dative bond. 
In covalent bond the electrons shared by both the atoms are contributed by both the atoms equally.
  What Happens When Aminoacids React With Alcohols?
Answer :
when alcohols reats with aminoacids esters are formed. The esters are volatile in contrast to free aminoacids.
R-CH-COOH + H2O-C2H5 -> R-CH-COO-C2H5 + H2O
NH2 NH2
      What Are Ligases?which Type Of Reactions They Will Catalyse?
Answer :
Ligases are the group of enzymes that catalyse the transfer of a group from one kind of molecule to another. These are also called transferases.


        Nh2-ch2-cooh Belongs To What Structure?
Answer :
its the structure of amino acid glacine
      Mention The Factors Affecting Solubility Of Compounds?
Answer :
temperature, pH, structure of compound i.e., whether the compd is straight chain or branched & molecular weight of compd.
      What Are Geometrical Isomerism? Explain Them With An Example?
Answer :
Geometrical isomerism is an example of stereo-isomerism. 
This occurs when substances have the same molecular formula, but a different arrangment of their atoms in space. There are three ways that this can happen: 
where there is a C=C bond in the molecule; 
where a molecule has rings; or 
where there is a >C=N bond.
      How 'salting Out' Process Is Used In Extraction?
Answer :
Proteins are precipitated from aqueous solution by high concentrations of neutral salts. This is the"salting -out" process.
Divalent and trivalent ions are more effective than univalent ions.
The salts commonly used for this purpose are NA2SO4,(NH4) 2SO4 Magnesium salts, and phosphates.
        What Is Saponification Of Oils?
Answer :
When fats are hydrolysed with alkhali,the free fatty acids react with alkali to form metallic acids.these salts are soaps and this process is called saponification.
       What Is Redox Potential Of An Organic Compound?
Answer :
The quantitative measure of the affinity of a compound to lose or gain electrons is the redox potential.
        What Is Lithipone?
Answer :
Lithipone is a white pigment.it is amixture of BaSO4&ZnS.
         What Is Difference Between Anti-aromatic And Non-aromatic Compounds?
Answer :
Anti aromatic compounds follows 4npi electron rule and are cyclic compounds, planar, where as non aromatic are non planar or planar, cyclic or acyclic.
         What Is The Range Of Uv & Vis Lamp In Spectrophotometer?
Answer :
o    uv lamp range is 200 nm to 340 nm. 
o    vis lamp range is 320 nm to 1100 nm. 
both of lamp range is mfg instument company voice of record is enculd the data range in lamp is 200 nm to 1200 nm.


           If Benzene And Tolune Both Can Be Mixed... What Is The Boiling Point For The Mixture And Its Density?
Answer :
If benzene and toluene mixed the boiling point will be ~ 90oC. Density will not change.
           Benzoic Acid Is A Weaker Than Para Nitro Benzoic Acid?
Answer :
in p-nitrobenzoic acid due to -I effect of nitro group hydrogen present in acia become more elecronegative and easily remove as proton and act like strong acid.
         What Is The Difference Between Sulphated Ash And Roi?
Answer :
There no difference between procedure, both are same. we generally term it as sulphated ash test/roi.in indian pharmacoepia, called it as roi and in usp, called it as sulphated ash tesh. both are used for the determination of content of inorganic matter in an organic substance.
      If Tis Below Reaction Does Happaen Means...,what Is The End Product.......? Naphthal + Toluene(or)benzene?
Answer :
high molecular weight easily we can seperate koH
       What Is The Difference Between Pvc And Upvc Plastic?
Answer :
PVC-POLYVINYL CHLORIDE AND uPVC IS THE Unplasticized polyvinyl chloride IT IS USED FOR building industry as a low-maintenance material.
         What Mean By Organic Chemistry?
Answer :
Organic Chemistry is a branch of Science, which deals study about carbon compounds except Carbon monoxide, Carbon di oxide and corbonates.
          Which Organic Compound Is Used As A Fuel In Jet Air Crafts? A. 100 Octane B. 90 Octane C. Kerosine Oil D. Diesel Oil
Answer :
Kerosine oil
      What Is The Difference Between An Ion And A Radical?
Answer :
An ion is a specie that have no unpaired electron and is charged, either positively or negatively i.e. may be a cation or an anion. It is formed due to heterolysis of a molecule
e.g HCl----> H+ + Cl- 
A radical is a neutral specie having atleast one unpaired electron and is formed due to homolysis of a molecule
e.g H-H -------> H* + H* 
The * shows an unpaired electron. Similarly CH3* is a radical.
         How To Synthsis Toluene To Benzaldehyde?
Answer :
from directly reaction of toluene to cromyl chloride (CrO2Cl2) at room temp. to form benzaldehyde.
         How To Make A 100ml Solution With Given 10gm Of Naoh?
Answer :
Take 100ml water and pore 10gr NaOH pellets sterr with gently boil. NaOH sol ready.
       How We Can Differentiate Between Oxalic Acid And Tartaric Acid?
Answer :
By Fluorescein test ... where tartaric acid " used in baking powder and found  in many food products 
oxalic acid : harmful in contact with skin or eyes  toxic .remove Ca ions From blood and also block Kidneys  Fluoresce in test depended on Light passes & usually in UV light
Question: What is the chemical formula of detergent?
 Answer: The chemical formula for detergent certainly is not "c3h8o5," as was suggested. ("c3h8o5" does not even exist as a molecule.)

Rather, the chemical formula for "detergent" really depends on what you mean by the word. By itself the word does not connoted any specific formula (must/must not have this function group).

Commercial detergents are made up of many different chemical compounds (different surfactants, colorants, pH modifiers, chlorinated and non-chlorinated whiteners, etc). For example, one effective (albeit harsh) surfactant is sodium lauryl sulfate (aka sodium dodecyl sulfate): C12H25NaO4S
Question: what is organic chemistry
 Answer: chemistry deals with organic molecules,and their physical and chemical properties chemistry deals with organic molecules,and their physical and chemical properties Source:
Question: What is the net charge of a non-ionized atom?
 Answer: In an atom, the number of protons is equal to the number of electrons and that one proton has the same positive charge value as an electron does a negative charge value.

Therefore, I am assuming that all atoms have no charge, zero, none, squat.

Non-ionized also means the atom has not suffered electron exchange, so a non-ionized atom is really just an atom (which is word redundancy).

This is what I know from AS level Chemistry, so I don't know if it's the same thing as more advanced chemistry (for university or something).
Question: What are KOH and HCl?
 Answer: KOH is potassium hydroxide, which is a strong base. HCl is hydrochloric acid, which is a strong acid.
Question: Why acetic has less conductivity than Hcl?
 Answer: Acetic acid has less conductivity, because it ionizes less in solution. HCl separates almost completely in solution to form the ions Cl- and H+. Acetic acid only partially ionizes into CH3COO- and H+ with lots of it staying as complete CH3COOH molecules. It is the concentration of ions in a solution, which determines its conductivity. An electric current passes through the solution by movement of these ions. The extent to which any partially ionized substance actually ionizes can be expressed as its pKa value.
Question: What is a substituted hydrocarbon?
 Answer: A substituted hydrocarbon is a hydrocarbon with one or more of the hydrogen is substituted with another element, (often a halogen such as chlorine or bromine) or another group of atoms such as -OH. Examples: -

a simple hydrocarbon is methane CH4. Substitute chlorine for hydrogen to get

CH3Cl Methyl Chloride is used for cleaning. Sub. Again to get

CH2Cl2 Methylene Chloride is used as paint stripper. Sub again to get

CHCl3 Chloroform is an ancient anesthetic. Sub again to get

CCl4 Carbon Tetrachloride is used in cleaning and fire extinguishers.

Substitute a single -OH group into -

CH4 to get CH3OH methanol or into C2H6 to get C2H5OH ethanol

The above examples all begin with unbranched non-cyclic hydrocarbons, but any hydrocarbon is a suitable target. A well-known instance is a double substitution of chlorine at opposite ends of a benzene ring to form paradichlorbenzene, commonly found hanging in toilet bowls. C6H6 becomes C6H4Cl2
Question: What is the difference between the law of multiple proportions and the law of definite proportions?
 Answer: Both laws have to do with relating to Dalton's Atomic Theory. The only difference is that the Law of Definite Proportions deals with elements combining to form ONE compound in a simple whole number ratio. The Law of Multiple Proportions is comparing the same 2 elements that make up 2 different compounds the division of these 2 ratios should equal a simple whole number ratio.

For example, Carbon and oxygen can combine to form carbon monoxide and carbon dioxide. If you calculated each compounds ration of oxygen to carbon, you would get the following ratios: compound A would equal a combining ratio of 1.34:1 (O:C). Compound B would equal a combining ratio of 2.67:1 (O:C).

If you divided the bigger ratio by the smaller ratio you would have that oxygen combines with a ratio of 2.67/1.34, which would equal 1.99:1, which is close enough to 2:1.
Question: Why chemists have not created a periodic table of compounds?
 Answer: One major reason I can think of, that has not been addressed yet, is the periodicity of the elements. You can line the elements up into neat functional groups--alkali metals, transition elements, halogens and so on. This you could not do with compounds, even if you had a separate table for hydrocarbons, one for elastomers, and one for dyestuffs... Compounds also find wide use as smaller blocks of larger compounds. We call these precursors. Take toluene. It is a very toxic compound, but if you compound it into toluene diisocyanate, then compound that into polyurethane, it becomes safe enough that you can build it into replacement hip joints. Chemists do keep books of compounds, but a table on a big sheet of paper the size of...oh, the entire side of a Wal-Mart store might be big enough? It could never happen.
Question: How do you extract ephedrine from a mineral block?
 Answer: You cannot extract ephedrine or pseudo ephedrine from a mineral block. Anyone who tells you that they have done it is either mistaken or a liar.
Question: What are the hydrocarbons?
 Answer: Hydrocarbons are compounds made entirely out of Hydrogen and Carbon
Question: What element was used to make the first atomic bomb?
 Answer: Uranium was used in the Hiroshima bomb and Plutonium in the Nagasaki one.
Question: What is the full form of hcl?
 Answer: The full form of HCL is hydrochloric acid or hydrogen chloride gas
Question: Are the chemical properties of lithium a metal metalloid or a nonmetal?
 Answer: Lithium, Li, is a metal. However, can also be a metalloid or a nonmetal.
Question: Is benzene a polar molecule?
 Answer: No, Benzene is a non-polar compound
Question: Do all explosions produce carbon dioxide?
 Answer: An explosion is nothing more than the rapid release of energy. This is most commonly due to the rapid combustion of a material, although nuclear explosions do not involve combustion. The combustion of any hydrocarbon or other carbon-containing substance ALWAYS produces carbon dioxide. This might include explosion due to a natural gas or gasoline.

It is possible, however, to explode substances that do not contain carbon, such as pure hydrogen (the very famous Hindenburg disaster in 1937 is a classic example of a very big hydrogen gas explosion. An explosion of hydrogen produces only water vapor (H2O), NOT carbon dioxide (CO2).

Also, nuclear explosions (both fusion and fission) themselves do not produce carbon dioxide, although they may cause surrounding objects to incinerate, which would release carbon dioxide.
Question: Where is tin obtained?
 Answer: Tin is obtained in various places tin is found mainly in the ore cassiterite, which is found in Malaysia, Bolivia, Thailand, and Nigeria.
Question: How do you solve Ideal Gas Law problems?
 Answer: The Ideal Gas Law is used to relate the pressure, volume, temperature, and amount of an "ideal" gas. Although many gases are not ideal in reality, you can usually use the Ideal Gas Law anyway. Here is how you solve these problems!

The Ideal Gas Law is PV = nRT.
Question: How many electrons are in benzene?
 Answer: There are 30 electrons in benzene. This includes 24 carbon electrons and 6 hydrogen electrons. There are 12 electrons shared between C and H, and 18 between C and C. (6 electrons in up ring, 6 in down ring and 6 between C and C).
Question: What is an oxidizing agent?
 Answer: Any chemical species that has a tendency to accept electrons and thereby undergoing reduction themselves is known as an oxidizing agent
Question: How can you tell if there is a dipole moment or not?
 Answer: A dipole moment is defined as a measure of the molecular polarity of a compound; the magnitude of the partial charges on the ends of a molecule times the distance between them (in meters).

In order for there to be a dipole moment, the element must have molecular polarity, which results from molecules with a net imbalance of charge (often a result of differences in electro negativity). If the molecule has more than two atoms, both shape and bond polarity determines the molecular polarity.

In general, look for a difference in electro negativity of the elements of a molecule which results in polarity and thus a possible dipole moment. Note that molecular shape influence polarity so molecules with the same elements but a different shape (and vice versa) will not have the same dipole moment.
Question: What is the direction of the dipole moment expected for carbon tetrachloride?


 Answer: 

It has no net dipole moment. Hence, it is non-polar
Question: What are the cons of eating organic foods?
 Answer: It is more expensive and you have less of a variety to choose. Stores like Wegamans have a variety of organic food though.
Since organic produce does not contain chemicals and stabilizers, it spoils more quickly. It also may appear "uglier" (asymmetrical, not shiny or waxy, dirty).
Question: What wavelengths can the human eye see?
 Answer: Human eye is sensitive to an approximate range of wavelength of radiations from 380nm to 760nm. This portion of electromagnetic spectrum is identified as Light
Question: Explain the method for the preparation of 1 normal solution of hydrochloric acid.
 Answer: Dilute 85ml of HCL to 1000ml
Question: Is HCl an acid or a base?
 Answer: HCl, or hydrochloric acid, as the name implies, is an acid. In fact, it is considered a strong acid because it dissociates completely in water to form H3O+ and Cl-.

However, it can also act as a base in reactions with acids stronger than it can like HClO4.
Question: Where does arsenic come from?
 Answer: (FeAsS) Arsenopyrite also known as mispickel is the most common mineral containing arsenic.
Question: how can determine the 'pka ' of a given component
 Answer: pka or pkb depends on the compound taken. when pH is measured and the concentration of compound is known, they can be determine by simple related formulas under acids & bases section which we learnt.

Other explanation may be measuring rate of ionization of acid or base with experimental setup and then calculating the negative logarithm of concentration of acidic or basic species.
Question: How reactive is Trimethylindium towards oxygen and water?
 Answer: Trimethylindium is extremely reactive towards oxygen and water. With low concentrations of oxygen (ppb to ppm to a few %), it immediately forms dimethylindium methoxide (Me2InOMe) as the first reaction product by insertion of O between In and C. With increased concentrations of oxygen (several %, atmospheric air or pure oxygen), it burns or explodes. Similar insertion reactions are expected with other elements of Group 16 (such as S, Se and Te) with highly vigorous outburst at higher concentrations of S, Se and Te.

Trimethylindium reacts readily and vigorously with water to form Me2InOH and Methane (CH4) gas if the concentration of H2O is very small (up to 1000's ppm). With high concentrations of water (% level), trimethylindium can burn and often explode leaving behind In (OH)3, In2O3 as the final products. Extremely violent reactions of trimethylindium are also known with oxidizers. Such as H2O2, KMnO4, HNO3, Bleach) and halogenated compounds (CCl4, CBrCl3, CBr2Cl2, CHCl3, C2Cl6, and halocarbon oils).
Question: Which is polar HCl or HF?
 Answer: This question is quite simple if you have an electro negativity chart:

Florine's Electronegativity: 4.0

Chlorine's Electronegativity: 3.0

Hydrogen's Electronegativity: 2.1

HCl: 3.0-2.1= .9 (Slightly polar)

HF: 4.0-2.1= 1.9 (Much more polar)
Question: What is a dipole moment?
 Answer: Dipole moment is the measure polarity of a polar covalent bond. It is defined as the product magnitude of charge on the atoms and the distance between the two bonded atoms. Its common unit is debye and SI unit is columb meter.
Question: How do you prepare a solution of 1 M HCl?
 Answer: Exactly how you prepare will depend on what you are starting with. Typically, to make a 1 M HCl solution, you will be starting with a stock solution of more concentrated HCl that you will then dilute.
Question: What is some importance of organic chemistry?
 Answer: In organic chemistry one uses it both medicinally one uses it to test for illness way back from ancient times. It is also a good diagnostic tool by smell feel or touch. You can actually heed the smell of decay in organic chemistry
Question: How many moles of HCl are present in .70 L of a .33 M HCl solution?
 Answer: ► First, remember definition of M (moles), M = moles of species / L.

0.33 M = 0.33 moles HCl / L

► Then, multiple your volume by the molar concentration:

0.33 moles HCl / L x 0.70 L = 0.231 moles HCl
Question: What is the use of glacial acetic acid?
 Answer: There are no medical uses to pure GAA, dilute concentrations can be used to remove warts or verucas; it can also be used via iontophoresis to treat bone spurs. Industrial uses include photography and the manufacturing of aspirin.
Question: What is the structure of a DNA molecule?
 Answer: A molecule of DNA is double-stranded. The molecule has the shape of a double helix.

The DNA molecule consists of two complementary strands oriented in an anti-parallel fashion. Each strand is composed of nucleotides. A nucleotide consists of a base (a purine or pyrimidine), a sugar (between the other two components) named deoxyribose, and a phosphate group. Nucleotides are linked to each other via phosphodiester bonds, forming a sugar-phosphate backbone to each strand.

The base of each nucleotide projects into the interior cavity of the helix. Each base is opposite another base: adenine (a purine) is always paired with thymine (a pyrimidine), and guanine (purine) with cytosine (pyrimidine); this phenomenon is called complementary base pairing.

Each nucleotide forms hydrogen bonds with its complementary base on the other strand. Two hydrogen bonds form between adenine and thymine; three hydrogen bonds form between guanine and cytosine.
Question: What is the dipole moment of chlorooctane?
 Answer: There are multiple forms of the molecule "chlorooctane." This is because the chlorine atom can be attached to the octane chain in several different places, and each different placement will result in a different dipole moment. If you specify the structure of the compound more precisely (1-chlorooctane or 2-chlorooctane for example), it is possible to determine its dipole moment.
Question: What is protein in Chemistry?
 Answer: Protein is a source of backup energy that your body stores, a large complex molecule made up of one or more chains of amino acids. Proteins perform a wide variety of activities in the cell.

Highly complex nitrogenous compounds found in all animal and vegetable tissues. Proteins, the principal constituents of the protoplasm of all cells (apart from water), are of high molecular weight, and consist essentially of combinations of amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins and each protein has a unique, genetically defined amino acid sequence that determines its specific shape and function.
Question: Is benzene an element or a compound?
 Answer: Benzene is a compound.
Question: What is the octet rule in chemistry?
 Answer: The octet rule is a simple chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas. This 8-electron configuration is especially stable because with 8 valence electrons, the s- and p-orbitals are completely filled (with 2 in the s-orbital, and 6 in the p-orbitals). Having completely filled orbitals provides increased stability due to something called "exchange energy."

The rule is applicable to the main-group elements, especially carbon, nitrogen, oxygen, and the halogens, but also the metals in the first two columns of the periodic table (but not to the transition metals in the middle of the periodic table). Note that the elements hydrogen (H) and helium (He) do not follow the octet rule, but rather the "duet" rule (2 electrons) because they do not have any p-orbital electrons.

In simple terms, molecules or ions tend to be most stable when the outermost electron shells of their constituent atoms contain eight electrons. The rule is commonly used in drawing Lewis dot structures.
Question: How are dipole attractions London dispersion forces and hydrogen bonding similar?
 Answer: They are all forces of attraction used to kelp keep molecules together. Since the molecules are the atoms bonded together, there are no electrons, or not enough, left over to bond with more atoms. The result would be trillions of tiny molecules floating about. Instead, each of these types of attractions draws the molecules together into solids, liquids, or gases.
Question: What is ciprofloxacin HCL used for what type?
 Answer: Ciprofloxacin is used to fight bacterial infections. I am currently taking this medicine to help cure mastoiditis.
Question: Can you show you the organic structure of cetearyl alcohol and tell me what organic family it is?
 Answer: Cetearyl alcohol is actually a mixture of both stearyl alcohol and cetyl alcohol (refer to links below for structures). Both of these compounds would be considered "fatty alcohols" due to their long carbon chains. Fatty alcohols are in the aliphatic hydrocarbon family. To draw the structure of "cetearyl alcohol" you would actually have to draw the structure of cetyl alcohol and the structure of stearyl alcohol.
Question: What is the chemical formula for Epsom salts?
 Answer: Epsom Salt chemical formula is Me245-H2O.
Question: What is a medicine dropper?
 Answer: A medicine dropper is an instrument used to measure small amount of liquids, usually in milligrams. You will first pinch the handle before you submerge it in the water.
Question: What are 3 facts on evaporation?
 Answer: 1. 80% of evaporation comes from the ocean.
2. 20% of evaporation comes from inland water.
3. Wind helps evaporation by moving it
Question: What is hydra?
 Answer: Hydra is a type of polyp. It is an animal, because it moves around like one even though it looks like a plant. A hydra is from the Phylum Cnidarian and belongs with others such as jellyfish and coral.
Question: How does spontaneous combustion occur?
 Answer: It is caused by a build up of sulfur in a person's body that eventually reacts to increased body heat.
Question: Is DNA organic?
 Answer: ► Of, relating to, or derived from living organisms: organic matter.
► Of, relating to, or affecting a bodily organ: an organic disease.

In addition, DNA would chemically be considered organic since it contains carbon as the primary chemical backbone of the molecule.
Question: How do you separate the colors of ink?
 Answer: The colors of ink can be separated by chromatography.
Question: How are dipole attractions London dispersion forces and hydrogen bonding similar?
 Answer: How are dipole attractions London dispersion forces and hydrogen bonding similar?
Question: What is the IUPAC name of benzene?
 Answer: The IUPAC name for Benzene is Benzene. It forms the basis for other IUPAC-named benzene derivatives like 1, 2-dimethylbenzene etc.
Question: What are the differences between organic and inorganic chemistry?
 Answer: Organic chemistry is the chemistry of carbon compounds while inorganic chemistry is the chemistry of all the rest of the elements on the periodic table.
Question: What is alum?
 Answer: Alum is a chemical (aluminum potassium sulphate); it tends to be whitish powder with several uses, including:

1. As an astringent
2. As an antibacterial
3. As a food preservative
4. As a 'Styptic pencil' to heal shaving cuts
5. To stem the flow of minor blood loss and cuts
6. Soaked into materials to make them flame retardant

There are other uses, but these are some of the more common ones.
Question: What is a tripod? How it is used?
 Answer: A tripod is a general term for a stand or support with three legs. It is often used to support a camera gun, or to place above the Bunsen burner in the science lab to heat/boil anything.

In the science laboratory, metal gauze is placed on top of it to give support to the beaker (An iron ring clamp with a ring stand can often be used instead and an iron ring allows for easy height adjustment).
Question: What is the equation for photosynthesis?
 Answer: 1) Light energy

2) == 6CO2 + 6H2O --------> C6H12O6 + 6O2 ==

3) Carbon dioxide + water +light energy------> carbohydrates+ oxygen
Question: What makes a molecule into an organic molecule?
 Answer: Any molecule that contains one or more atoms of Carbon is an organic molecule. All elements that are composed by Carbon are studied by Organic Chemistry.
Question: What is the direction of the dipole moment expected for hydrogen bromide?
 Answer: The HBr molecule is linear (obviously, since it contains only two atoms). The dipole moment is a vector, parallel to the bond, pointing toward the partially positively charged atom, which is, in this case, the hydrogen. The magnitude of the dipole moment is the difference in the partial electrical charges on each atom times the spatial separation of the atoms in the bond. In a molecule with more than two atoms (more than one bond), the dipole moment of each bond must be added vectorially and the resultant vector will determine the dipole moment of the molecule. For instance, carbon dioxide has two carbon-oxygen double bonds of high polarity, but because the molecule is linear, and the individual dipoles oppose each other, the carbon dioxide molecule has no net dipole moment.
Question: What is the difference in the modern periodic table and Mendeleevs table?


 Answer: 

The periodic table is now arranged in the order of increasing atomic numbers. In addition, it is said that the modern table makes it easier to read and learn. The way that it is set up now allows scientists to make changes if necessary. Hope this helps Source


The key differences between Mendeleev and modern periodic table

1. Mendeleev?s periodic table was based on the increasing atomic masses while the modern periodic table is based on the increasing atomic numbers.

2. Mendeleev?s periodic table had gaps for the missing elements at that time. Modern periodic table                                has no concept as such.

3. Mendeleev?s periodic table has 8 vertical columns called groups and 12 horizontal rows called periods.
Modern periodic table has 18 columns called groups and 7 rows called periods.

4. Mendeleev periodic table doesn?t support the fact of the existence of isotopes.

Modern periodic table supports this fact as the classification is based upon the atomic number, rather than the atomic weight of the element

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