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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Give water gas shift reactio |
| Answer» Water gas shift reaction involves water vapor reaction with carbon monoxide to give carbon dioxide and hydrogen gas. The reaction isCO + H2O → CO2\xa0+ H2Felice Fontana discovered this water gas shift reaction in 1780. It was made in England in the year 1828. The water gas was produced by blowing steam through red hot coke, the reaction is C + H2O → CO + H2 | |
| 2. |
Two gases which are responsible for green house effect |
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Answer» Methane and co2 SO2andNO2 |
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| 3. |
What is different between stable and un stable gases |
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| 4. |
What is different between stable and unstable gasses |
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| 5. |
What is the composition of Portland cement? also write the ratio of constituents for good cement. |
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| 6. |
Define unit cell |
| Answer» Unit Cell is the smallest part (portion) of a crystal lattice. It is the simplest repeating unit in a crystal. The entire lattice is generated by the repetition of the unit cell in different directions.Primitive Unit Cells: When the constituent particles occupy only the corner positions, it is known as Primitive Unit Cells.Centered Unit Cells: When the constituent particles occupy other positions in addition to those at corners, it is known as Centred Unit Cell. | |
| 7. |
Explain why BF3exists whereas BH3 does not? |
| Answer» BH3 \xa0molecule is electron deficient in nature as the B atom has only 6 electrons around it so it exist in the form of dimer i.e. B2H6. BF3 is also electron deficient but because of larger size of F atom it can not undergo dimerization. | |
| 8. |
Define Dehydration of ethanol. |
| Answer» Reaction of ethanol with excess concentrated sulphuric acid acting as dehydrating agent at 443 K results in the dehydration of Ethanol leading to the formation of Ethene.2CH3CH2OH {tex}\\;\\xrightarrow[{H_2SO_4}]{Hot\\;Conc}{/tex} 2CH2=CH2 + H2OEthanol Ethene | |
| 9. |
What are electrophiles? Give one example of electrophilic substitution reaction |
| Answer» \xa0Electrophiles (Electrophilic reagents): Electrophiles are electron loving chemical species having an atom which is deficient in electrons. There are two types of electrophiles:(a) Positively charged ions or positive electrophiles: These are deficient in electrons and carry a positive charge. For example H+\xa0(hydrogen ion) H3O+(hydronium ion),\xa0\xa0(Nitronium ion),(b) Neutral electrophiles. These are electrophilic reagents in which the electron deficient atom does not carry any charge. For example AlCl3, FeCl3, BF3, SnCl4. Carbenes also act as electrophiles because the carbon in them has only six electrons.\xa0Since both positively charged and neutral electrophiles are short by a pair of electrons, they have strong tendency to attract electrons from other sources and hence behave a Lewis acids.\xa0Electrophiles always attack the substrate molecule at the point of high\xa0electron density.\xa0 | |
| 10. |
Axial bonds are longer as compared to equatorial bonds inPCl5. |
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| 11. |
What is the radius of sodium atom if it crytallises in bcc structure with edge length 400pm? |
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| 12. |
What gas leaked to bring havoc in bhopal tragedy |
| Answer» Bhopal gas tragedy was caused by the leakage of methyl isocyanate gas ( CH3 -N=C=O) from the Union Carbide India limited pesticide plant situated in Bhopal.\xa0 | |
| 13. |
SiCl4 is easily hydrolysed but CCl4is not |
| Answer» \tCCl4 doesnot undergo hydrolysis by water because the carbon atom is small and is shielded by larger chlorine atoms.\tCarbon does not have 3d atomic orbitals that water can use to form co-ordinate bonds.\tIn SiCl4, the silicon atom is larger than the carbon atom and also has available 3d atomic orbitals for bonding, thus hydrolysis is possible. | |
| 14. |
What is surface tension and surface energy |
| Answer» Surface energy is defined as the mechanical work required to increase the unit area of free surface under isothermal condition.Surface tension is the property of any liquid by virtue of which tries to minimize its free surface area. Surface tension of a liquid is measured as the force acting per length on an imaginary line draw tangentially on the surface of the liquid. | |
| 15. |
What is vapour pressure????? |
| Answer» Vapour pressure can be defined as pressure formed by the vapor of the liquid (or solid) over the surface of the liquid. This pressure is formed in a thermodynamic equilibrium state in a closed container at a certain temperature. Liquid’s evaporation rate is identified by the equilibrium vapor pressure. Vapour pressure increases with the temperature. The boiling point of the liquid is the point when the pressure exerted by surrounding equals to the pressure exerted by vapor. | |
| 16. |
What is VB theory |
| Answer» Valence bond theory was proposed by Heitler and London in 1927 based on atomic orbitals and their configuration.A covalent bond is formed when pure, valence atomic orbital of one atom overlaps with another pure, valence atomic orbital of another atom. During covalent bond formation energy releases that means stability increases.Each of the overlapping orbitals contains the unpaired electron of opposite spin.The electron pair is shared by both the atoms.\xa0The strongest bond is formed when the orbitals of the two atoms overlap to the maximum extent.Based on the overlapping of orbitals, two types of covalent bonds are formed. These are known as sigma and pi bonds.Sigma bonds are formed by the end-to-end overlap of atomic orbitals along the inter-nuclear axis known as a head-on or axial overlap.End on over lapping is of three types, they are\xa0s-s overlapping, s-p overlapping and p-p overlapping. | |
| 17. |
No. of molecule of ethane. |
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Answer» That tells you that 32 grams of ethane are a mole. A mole is 6.02 x 10^23 molecules. This number is called “Avogadro\'s Number”. Your sample of ethane is only 15 grams so obviously, you don\'t have a whole mole. Question in incomplete |
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| 18. |
How many electrons will be present in the subshells having m value of -1/2 for n=4 |
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| 19. |
Chlorophyll is coordination compound of1.Li2.Na3.Ca4.Mg |
| Answer» magnesium | |
| 20. |
Which of the following does not have allotropes?1.P2.S3.C4.I |
| Answer» 4 iodine | |
| 21. |
Difference between kp and kc |
| Answer» Kp is used for reactions involving gases, and the equilibrium constant is expressed in terms of the partial pressures of the gases. Whereas, Kc is used as a general constant, and the concentrations (in moles/liter) are used in calculating its value.Kc is the ratio of products concentration over reactants concentration and Kp is the ratio of products partial pressures and reactants partial pressures. | |
| 22. |
Equibrium in chemical processes : dynamic Equibrium |
| Answer» Equilibrium in Chemical ProcessesYou may have learnt about reversible reactions. As the name suggests, these reactions occur in the forward and reverse direction. In such reactions, when the rate of the forward and reverse reaction is equal, the concentrations of the reactants and products remain constant. At such a stage, the reaction is said to be in chemical equilibrium.However, this equilibrium is said to be dynamic in nature. This is because it consists of a forward reaction where the reactants react to give products and reverse reaction where the products can react to give back the original reactants. Let’s understand these chemical processes below.Dynamic Nature of Chemical Processes in EquilibriumLet’s consider the following reversible reaction –A + B ⇌ C + DAs time progresses, the products (C and D) accumulate while the reactants (A and B) deplete. This results in a decrease in the rate of the forward reaction and an increase in the rate of reverse reaction. Ultimately, both reactions occur at the same time reaching a state of equilibrium. This equilibrium can be reached from either direction.Haber’s ProcessThe German chemist, Fritz Haber developed a method to manufacture ammonia from dinitrogen and dihydrogen. This process is the Haber’s process.N2(g) + 3H2(g) ⇌ 2NH3(g)Haber started out with known amounts of dinitrogen and dihydrogen, maintained at high temperature and pressure, and noted the amount of ammonia produced at regular intervals. As the reaction proceeds, after some time, he noted that the composition of the mixture remains the same even though some reactants are still present. This shows that the reaction has reached equilibrium.chemical equilibriumHaber’s process [Source: Wikimedia Commons]Further, Haber’s process demonstrates the dynamic nature of chemical equilibrium in the following manner. Keeping the experimental conditions same as above, hydrogen (H2) was replaced with deuterium (D2). This gives rise to ND3 as the product instead of NH3. Both reactions, one involving H2 and one with D2 were allowed to proceed to equilibrium.When these two mixtures (H2, N2, NH3 and D2, N2, ND3) were mixed and left for a while, it was observed that the concentration of ammonia was the same as before. Although, mass spectrometry revealed that along with ammonia, all forms containing deuterium and dihydrogen were present (NH2D, NHD2, ND3, H2, HD and D2).This shows that the scrambling of H and D atoms must be possible due to the continuation of the forward and reverse reactions. There would have been no mixing of isotopes if the reaction had stopped on reaching equilibrium.Therefore, chemical reactions reach a state of dynamic equilibrium in which the rates of forwarding and reverse reactions are equal and there is no net change in composition.Chemical Equilibrium is BidirectionalWhether we start a reaction using reactants or products, equilibrium is attainable from both sides. Let’s consider the following reaction.H2(g) + I2(g) ⇌ 2HI(g)If we start the reaction with equal initial concentrations of H2 and I2, then the reaction proceeds in the forward direction where the concentration of H2 and I2 decreases and that of HI increases until it reaches equilibrium.If we start the above reaction in the reverse direction, then the concentration of HI decreases while that of H2 and I2 increases till it reaches equilibrium. Therefore, if the total number of atoms of an element are same in a given volume, we get the same equilibrium mixture whether we start it with reactants or with products | |
| 23. |
The ratio of wavelength of layman amd balmer |
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| 24. |
whai is laws conservation |
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Answer» Hello Dhama... According to law of conservation of mass ..matter neither be created nor be destroyed byAntoine lavoisier .. |
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| 25. |
What is the formula to find number of isomers of an organic compound? |
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| 26. |
On google it\'s 16 so what shud i take????? |
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| 27. |
Boron is used in making bullet proof coats. Isn\'t it?????? |
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| 28. |
Main important topic |
| Answer» Molecules stucture and chemical bonding | |
| 29. |
Explain plunk constant |
| Answer» Planck\'s constant is a proportionality constant.Its value is approx. equal to 6.626x10^-34 joules sec. | |
| 30. |
How to convert Ethene to ethane Benzene to TolueneMethane to ethaneEthyne to ethane |
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| 31. |
Importance and scope of chemistry in points |
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Answer» NCERT Its given in the NCERT book.. just make ur own notes.. thats the best way to study n remmember |
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| 32. |
Calculate the total no of bicarbonate ions present in fused or molten Mg(HCo3)2 having mass 146grams |
| Answer» Moles of Mg(HCO3)2 =GIVEN MASS/MOLAR MASS=146/146===1 MOLEsince, 1 mole=6.022 *10²³ particles /ions of Mg(HCO3)2so, (HCO3)2 IONS present in given compound will be===2*6.022*10²³=12.044 * 10²³ ions... Because 2 moles of bicarbonate ion is present in 1 mole of magnesium hydrogen carbonate... | |
| 33. |
Important of chemistry? |
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Answer» Check in Ncert...In the first page of 1st chapter..It will help uh Chemistry plays a very important role in industries for manufacturing of medicine , dyes etc |
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| 34. |
Law of reciprocal proportion P / \\ H---Cl |
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| 35. |
What is the momentum of particles associated with de broglie\'s wavelength of 1A°? |
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| 36. |
Discribe quantum mechenical model of atom |
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Answer» Quantum mechanics is based on a fundamental equation which is called Schrodinger equation.\xa0The solutions to this equation give the values of E and Ψ.Solving the equation gives us many values of E. But out of these values, only certain solutions are permitted. Each permitted solution is highly significant as it corresponds to a definite energy state. Thus, we can say that energy is quantized. That is, it can have only certain specific values. Ψ gives the amplitude of the wave. All the information about the electron in an atom is stored in Ψ which is called its wave function.But the square of the amplitude, that is, Ψ2 gives us the region in which the probability of finding an electron is maximum. Ψ2 is called probability density.This region of space around the nucleus where the probability of finding an electron is maximum is called an orbital.In an atom a large number of orbitals are permissible.\xa0Each orbital is designated by a set of numbers known as quantum numbers
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| 37. |
sir in chapter 2 important question |
| Answer» All imp.topics | |
| 38. |
Calculate molality and mole fraction of 10 percent nitric acid (Hno3) |
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| 39. |
how to solve numericals easily help me plzof chapter 2 |
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| 40. |
Provide me best youtube channel s to study maths physics n chemistry ??? |
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Answer» Okk yaa... aapne pucha tha isiliye bta diya Yes i knew he is a great teacher Allakh pandey is a best teacher on youtube for physics and chemistry. Channel name (physics wallah) |
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| 41. |
Define telluric screw |
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| 42. |
Molar mass of C8 H6 O4 |
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Answer» 12*8+1*6+16*496 +6+64 = 166g 166g 166g/mole Molar mass of C8H6O4 is =166 |
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| 43. |
How we can find out atomic mass without knowing neutron |
| Answer» By solving it with the help of school teacher | |
| 44. |
What is the avagadro no. |
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Answer» 6.023×10^23 mol/ion/atom/electron It is equal to 6.022×10^23 molecules/ions/atoms/electrons |
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| 45. |
What is redix reduction |
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Answer» Redox reaction is a reaction in which oxidation and reduction take place simultanously . If you want to ask about redox reaction so it is the combination of oxidation and reduction reaction |
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| 46. |
Explain molarity ,molality,mole fraction |
| Answer» Molarity:-the number of moles of solute dissolve in 1 litre of solution ...and it is denoted by (M)...Molality:-the number of moles of solute dissolve in 1kilogram of solvent..and it is denoted by (m)...Mole fraction:-the ratio of the number of mole of a particular component to the total value of the solution... | |
| 47. |
When will result come of class 10? |
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Answer» In 2nd week of may cbse announced officially Next week said Anurag Tripathi Secretary of CBSE Not declared by CBSE |
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| 48. |
How we can find electrons in NH4 (ammonium)?? |
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| 49. |
If mass is the amount of matter, then its SI unit should be in number but why is its unit KG? |
| Answer» The mass is all about the area or weight (m×g) that any matter have covered so mass is calculated in kg | |
| 50. |
Which subject to select for percentage all or best 5 |
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