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. |
An aqueous solution freezes at -0.186c kf =1.86 kb=0.512.what is the elevation on boiling point |
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Answer» Depression in freezing POINT (ΔTf) = KF x m 0.186 = 1.86 x m m = 0.1 Now as we have got the molality, m= 0.1 ELEVATION in boiling point (ΔTb) = Kb x m → ΔTb = 0.512 x 0.1 → ΔTb = 0.0512 Therefore, the elevation in Boiling point is 0.0512. Hope it HELPS!! |
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| 2. |
Chemical equation of acetic acid and sodium bicarbonate |
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Answer» (sodium bicarbonate or BAKING SODA) NaHCO3 + HC2H3O2 (vinegar or acetic acid). products are water, carbon DIOXIDE, and sodium ACETATE (NaC2H3O2). |
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| 3. |
PbO2 acts as oxidising agent. Why? |
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Answer» It has the ABILITY tooxidize other SUBSTANCES — in other WORDS to cause them to lose electrons.... |
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| 4. |
Conversion of ethyl magnesium chloride to propan-1-ol |
| Answer» GRIGNARD REAGENT FOLLOWED by ACID HYDROLYSIS | |
| 5. |
When hydrogen gas passes through soap solution why are the bubbles released? |
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Answer» Hydrogen gas gives a POP SOUND when it enters base SOLUTIONS.(Soap is a basic PRODUCT). |
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| 6. |
Difference between thermal and photochemical reaction |
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Answer» HELLO DEAR STUDENT HERE IS YOUR ANSWER Difference between thermal reactions and photochemical reactions. In a photochemical reaction, EVERYTHING starts with absorption of a photon. I.e. a ground state reactant is excited to the FIRST excited state. HOPE THISE HELPS |
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| 7. |
Write any two application of fractional distillation |
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Answer» 1. To separate different gases from LIQUID AIR. |
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| 8. |
What is dipole moment?? |
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Answer» The MATHEMATICAL product of the separation of the ENDS of a dipole and the MAGNITUDE of the charges. |
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| 9. |
What will happen when 2g of ferrous sulphate crystals are heated in a boiling tube |
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Answer» Here is u r answer |
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| 10. |
Why Alpha particle scattering experiment was possible by using gold foil only and not by foil of any other metal |
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Answer» HEYA!! |
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| 11. |
Why bond angle of hydrides decrease down the group 16? |
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Answer» The hydrides of group 16 have tetrahedral geometry. With TWO lone pairs of the ELEMENTS. There is an increase in the bond angle as we move down the group because -The ELECTRON negativity of elements decrease as we move down. -The lone PAIR - bond-pair repulsion is stronger is than lone pair-lone pair or bond pair bond-pair interaction. -But as the electronegativity decreases, the repulsion also decreases which RESULTS in a decrease in bond angle.
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| 12. |
State the chemical properties on which the following uses of baking soda are based:(a) as an antacid (b) as a soda fire extinguisher (c) to make cake soft and spongy. |
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Answer» A) baking soda is a mild BASE which can dilute the excess ACID formed during indigestion. Hence it acts as an antacids. |
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| 13. |
How glycerol reach with oxalic acid |
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Answer» Glycerol reacts with OXALIC acid in two ways. Formation of formic acid. When glycerol is HEATED with crystalline oxalic acid at 100 - 110°C, formic acid is PRODUCED. ... When heated with oxalic acid at 260°C, allyl ALCOHOL is formed. |
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| 14. |
Write down the expressions of equilibrium constant for the following reactions:(i) 2SO2(g) +O2(g) 2SO3(g)(ii) N2O4(g) 2NO2(g) |
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Answer» Answer: |
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| 15. |
Indicate whether you would expect the entropy of a system to increase or decrease of thefollowing: (i) N2(g) + 3H2(g) → 2NH3(ii) O2(g) → 2O(g) |
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Answer» It will INCREASE DEFINITELY |
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| 16. |
Class 11 chemistryAn electron is in one of the 3d orbitals. Give the possible values of nl, l and ml for this electron. |
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Answer» HEY there!!! ▶For the 3D orbital :- ✴Principal quantum number (N) = 3 ✴Azimuthal quantum number (L) = 2 ✴Magnetic quantum number (ml) = – 2, – 1, 0, 1, 2 ______________________ Hope it will help you☺ |
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| 17. |
Which gas is liberated when dilute hydrochloric acid reacts with sodium carbonate ? |
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Answer» So DILUTE hydrochloric acid is REACTING here |
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| 18. |
Why electron gain enthalpy of nitrogen is ZERO? |
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Answer» ELECTRON gain ENTHALPY is the ENERGY released when one mole of electrons are added to the isolated gaseous ATOMS of an element. Electron gain enthalpy is said to be positive an electron is added to an element And, it is negative when an electron is removed from the element Since the ELECTRONIC configuration of nitrogen is 2s2 2p3, it has a half filled p shell which is a stable configuration. Thus, it has a relatively low tendency to gain or lose electrons and its electron gain enthalpy is zero. |
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| 19. |
Why secondary and tertiary amines cannot be prepared by gabriel phthalimide synthesis? |
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Answer» Because there is no any other places for nitrogen |
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| 20. |
Nitrogen is used to fill electric bulbs because it..... (a) Makes the bulb give more light (b) Does not support combustion (c) Heavier than air (d) None of these |
| Answer» B) does not SUPPORT COMBUSTION | |
| 21. |
Question :-Why is the value of Avogadro number 6.022 into 10 raise to power 23 and not any other value? |
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Answer» Hey there!!! |
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| 23. |
Name the element eka phosphorus |
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Answer» ☺❤☺❤☺HEY MATE YOUR ANSWER IS HERE. .....☺❤☺❤☺ |
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| 24. |
What is the effect of adding sodium hydroxide solution to these olfactory indicators |
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| 25. |
If 4g of oxygen diffuse through a very narrow hole, how much would have diffused under identical conditions? |
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Answer» Diffusion (and effusion),in fundamental terms, follow Graham's law, which can be stated as: Rate1/Rate2 = √(M2/M1) where: Rate1 and Rate2 = rates of diffusion of the two gases (often in terms of moles per unit time) M1 and M2 = molar masses of the the two species (g/mol) Let's call hydrogen species 1 here, and oxygen species 2. We are told 4 g of O2 diffuse in a certain time. 4 g of O2 = 1/8 mol, since the molar mass of O2 is 32 g/mol. So the rate at which O2 is DIFFUSING is (1/8) mol in t SECONDS, or ((1/8)/t) mol/s So, for quantities to put into Graham's law, we have: M1 = 2 g/mol (for hydrogen) M2 = 32 g/mol (for oxygen) Rate1 = UNKNOWN (we are trying to solve for this) Rate2 = ((1/8)/t) mol/s So, using Graham's law, we can now solve for the rate of hydrogen flow in mol/s. (Rate1/Rate2) = √(M2/M1) --> (Rate1/[(1/8)/t)]) = √(32/2) = √16 = 4 Thus, hydrogen diffuses four times faster than oxygen, on a mole/second basis. So, Rate1 = [(1/8)/t]*4 = (4/8)/t = (1/2)/t Now, the diffusion of hydrogen is said to occur over the same period as the diffusion of oxygen, so Rate1 is measured over the same time. Thus: Rate1 = (mol of hydrogen diffusing)/t,where t is the same t as above (for Rate2). So, combining the LAST two equations, we GET: (number of moles of hydrogen diffusing)/t= (1/2)/t Thus, the number of moles of hydrogen diffusing is 1/2 mol. 1/2 mol of molecular hydrogen has a mass of 1/2*(2 g/mol) = 1 g. Thus, 1 g of hydrogen would diffuse in the same time as 4 g of oxygen. This may seem counter-intuitive, but remember that Graham's law relates molar diusion rates, not mass diffusion rates. And, even though the hydrogen diffuses faster, it is also 16 times lighter than oxygen. So, in mass terms, only half as much mass of hydrogen diffuses in the same time. |
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| 26. |
Calculate the nmber of moles for 56g of ne (atomic mass Ne =20u |
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Answer» No. of MOLES =GIVEN weight÷molecular weight. |
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| 27. |
Why bond energy of c=c is least than c-c? |
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Answer» Hey mate is your ANSWER |
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| 28. |
How many elements were known at Newlands' time? |
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| 29. |
Latent heat of vaporization |
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Answer» Latent heat of vaporization is a PHYSICAL PROPERTY of a substance. ... When a material in LIQUID state is given energy, it CHANGES its phase from liquid to vapor; the energy ABSORBED in this process is called heat of vaporization. The heat of vaporization of water is about 2,260 kJ/kg, which is equal to 40.8 kJ/mol. |
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| 30. |
what is redox reaction? identify the substance oxidized and substance reduced in the reaction 2PbO+C----------->2Pb+CO2 |
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Answer» Wh N oxidation and REDUCTION both are TAKING place in one reaction than its CALLED REDOX reaction PbO is being reduced in above reaction because it losses oxygen in the rection |
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| 31. |
Molicular formula of mithan ao ethan give answar |
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Answer» Hi Nishith....... here is ur ans..... MOLECULAR FORMULA of methane is CH₄ and molecular formula of ethane is CH₃-CH₃ or C₂H₆. hope U got it. With LOVE. All the best. pls mark BRAINLIEST. |
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| 33. |
an aromatic organic compound A with molecular formula C8H8O give positive DNP and iodoform test it neither reduce tollens reagent nor does it decolourise bromine water white the structure of A |
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Answer» Compound A with molecular formula C8H8O give positive DNP and iodoform test it neither reduce tollens REAGENT nor does it decolourise BROMINE water white.The structure of A is BENZOPHENONE i.e PhCOCH3. As it is a ketone, it can not reduce tollen's reagent to give silver mirror. It also does not decolourise bromine water as double BOND of phenyl RING is involved in reaction with bromine water.Hence this compound A is nothing but a ketone. |
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| 34. |
The given reaction 2fecl3+Sncl2= 2fecl2+Sncl2 is example ofa) first order reaction b) second order reaction c) third order reaction |
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Answer» It MIGHT be 3RD ORDER reaction |
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| 35. |
What is thermite reaction.write a chemical equation for it |
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Answer» Hey mate there is your ANSWER : |
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| 36. |
The rate of first order reaction is 1.5*10^-2 molL-1/min-1 at 0.5 m .concentration of the reactant .the half life of the reaction is |
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Answer» Answer : The half life of the reaction is, 23.1 minutes. Solution : GIVEN, RATE of first ORDER reaction = Concentration of reactant = 0.5 m = 0.5 mole/L
The expression for rate of reaction is, Now put all the given values in this formula, we get the value for rate constant. The formula for half life for first order reaction is, Now put the value of K, we get the value of half life. Therefore, the half life of the reaction is, 23.1 minutes. |
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| 37. |
What is the role of nacn in the extraction of silver from a silver ore? |
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Answer» NaCn is use for leaching of Ag ORE in the presence of air from which the silver is OBTAINED LATER by replacement. |
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| 38. |
Do magnesium react with oxygen and water |
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Answer» Yes when magnesium RIBBON is BURNED it FORMS magnesium OXIDE when this magnesium oxide is dissolve with WATER it forms magnesium hydroxide |
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| 39. |
What are the disadvantage of burning wood as fuel |
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Answer» Here is your ANSWER |
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| 41. |
Why is the electronic configuration of chromium and copper difference? |
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Answer» Explanation: There are TWO main EXCEPTIONS to electron configuration: CHROMIUM and copper. In these cases, a completely FULL or half full d sub-level is more stable than a partially filled d sub-level, so an electron from the 4s ORBITAL is excited and rises to a 3d orbital. give me thanks for answer |
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| 42. |
what is the entropy change for the conversion of 1g of ice to water at 273 King and 1 atmospheric pressure |
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Answer» Your QUESTION is in this way |
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| 43. |
Formula of alcohol in chemisty |
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Answer» The FORMULA is |
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| 44. |
Heating limestone in a lime kiln to form quicklime is which type of reaction |
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Answer» Hey DEAR Here is ur ans it's a exothermic reaction as ALOT of heat produce in this process... Hope it HLPS U ☺☺ |
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| 45. |
arrange according to their flocculation power in the cogulation of negatine sol ? arrange the following ions Na+ , Al+3 , Ba +2 |
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Answer» (1) By electrophoresis: In electrophoresis the colloidal particles move towards oppositely charged electrode. When these come in contact with the electrode for long these are discharged and precipitated. (2) By mixing two oppositely charged sols : When oppositely charged sols are mixed in almost equal proportions, their charges are neutralised. Both sols may be partially or completely precipitated as the mixing of ferric hydroxide (+ve sol) and arsenious sulphide (–ve sol) bring them in precipitated form. This type of coagulation is called mutual coagulation or meteral coagulation. (3) By boiling: When a sol is boiled, the adsorbed layer is disturbed due to increased collisions with the molecules of dispersion medium. This REDUCES the charge on the particles and ultimately they settle down to form a precipitate. (4) By persistent dialysis: On prolonged dialysis, the traces of the electrolyte present in the sol are removed almost completely and the colloids become unstable. (5) By addition of electrolytes: The particles of the dispersed phase i.e., colloids bear some charge. When an electrolyte is added to sol, the colloidal particles take up ions carrying opposite charge from the electrolyte. As a RESULT, their charge gets neutralised and this causes the uncharged, particles to come closer and to get coagulated or precipitated. For example, if solution is added to sol the ions are attracted by the negatively charged sol particles and their charge gets neutralised. This lead to coagulation. (6) Hardy schulze rule : The coagulation capacity of different electrolytes is different. It depends upon the valency of the active ion are called flocculating ion, which is the ion carrying charge opposite to the charge on the colloidal particles. “According to Hardy Schulze rule, greater the valency of the active ion or flocculating ion, greater will be its coagulating power”thus, Hardy Schulze law state: (i) The ions carrying the charge opposite to that of sol particles are effective in causing coagulation of the sol. (ii) Coagulating power of an electrolyte is DIRECTLY proportional to the valency of the active ions (ions causing coagulation). For example to coagulate negative sol of , the coagulation power of different cations has been found to decrease in the order as, Similarly, to coagulate a positive sol such as , the coagulating power of different anions has been found to decrease in the order : (7) Coagulation or flocculation value “The minimum concentration of an electrolyte which is required to cause the coagulation or flocculation of a sol is known as flocculation value.” or “The NUMBER of millimoles of an electrolyte required to bring about the coagulation of one litre of a colloidal solution is called its flocculation value.” Coagulation value or flocculating value (8) Coagulation of lyophilic sols (i) There are two FACTORS which are responsible for the stability of lyophilic sols. (ii) These factors are the charge and solvation of the colloidal particles. (iii) When these two factors are removed, a lyophilic sol can be coagulated. (iv) This is done (i) by adding electrolyte (ii) and by adding suitable solvent. (v) When solvent such as alcohol and acetone are added to hydrophilic sols the dehydration of dispersed phase occurs. Under this condition a small quantity of electrolyte can bring about coagulation. |
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| 46. |
Carbon has a tendency to form long chain compounds but silicon does not. Why? |
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Answer» Carbon has catenation tendancy due to which it can FORM LONG CHAINS . |
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| 47. |
2500 cm cube of hydrogen is taken as STP the pressure of this gas is further increased by 2 and a half times temperature remaining constant volume will be occupied by hydrogen now |
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Answer» Given, V1 =2500 cm3 |
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| 48. |
Explain the significance of four quantum numbers |
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Answer» Hi FRIEND this is ur answer |
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| 49. |
Which has high dipole moment H2O or H2S |
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Answer» OXYGEN is a smaller ATOM and is more electronegative, so H2O WOULD be more polarized and have smaller BOND angle. Thus, H2O has higher DIPOLE moment. |
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| 50. |
What do you mean by liquor ammonia fortis |
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Answer» Liquor Ammoniae Fortis is a STRONG Solution of Ammonia. ... Nh3 - An aqueous solution CONTAINING 33% of ammonium, NH3. A COLORLESS LIQUID with a PUNGENT, suffocating odor. |
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