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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. |
Define "Soap" . |
| Answer» SOLUTION :SOAP is a sodium or potassium salt of higher FATTY acids such as OLEIC, STEARIC , lauric, palmitic acids . | |
| 2. |
Define shape - selective catalysis. Name the process by which alcohols convert directly into gasoline and give a variety of hydrocarbons. |
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Answer» SOLUTION :The catalytic reaction that depends upon the pore structure of the catalyst and the size of the reactant and PRODUCT molecule is called shape-selective catalysis. ZEOLITE catalyst ZSM-5 is used to CONVERT alcohols directly into gasoline by dehydrating them. A variety of hydrocarbons is OBTAINED in the process. |
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| 3. |
Define shape selective catalysis. Give an example of a shape selective catalyst. |
| Answer» Solution :Catalysts which ADSORB the molecules selective on the BASIS of size and LEAVING others are called shape selective catalysts. Zeolites are shape selective catalysts, e.g., a zeolite called ZSM-5 converts alcohols to GASOLINE. | |
| 4. |
Define- Salt hydrolysis. |
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Answer» Solution :Salts completely DISSOCIATE in AQUEOUS solution to GIVE their constituent ions. The ions so produced are hydrated in water IN certain cases, the cation, ANION or both react with water and the reaction is called salt hydrolysis e.g. `NaOH_(aq) +HNO_3 (aq) to NaNO_3(aq) + H_2O_(f)` |
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| 5. |
Define reverse osmosis. Give one use of it. |
| Answer» Solution :Is osmosis, NET FLOW of solvent across the semipermeable membrane is from solvent to solution. The flow can be reversed by applying pressure greater than osmotic pressure on the solution. This is called reverse osmosis. It is used for DESALINATION of sea water. | |
| 6. |
Define reverse osmosis. Write its one use. |
| Answer» SOLUTION :DESALINATION of WATER. | |
| 7. |
Define restricted rotation and give on example each of acyclic and cyclic compound, which can show geometrical isomersm. 1 |
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Answer» C=C, C=N, ring etc `(##RES_CHM_SIM_E01_003_A01##)` (a `NE` b, d `ne` e) |
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| 8. |
Define resistivity of a substance. |
| Answer» SOLUTION :Resistivity of a substance is its RESISTANCE when it is ONE metre LONG and its area of cross-section is one `m^(2)`? | |
| 9. |
Define Resistivity . Give its unit. |
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Answer» Solution :`rho` (rho) is called the specific resistance (or) RESISTIVITY and it is defined as the resistance of an electrolyte CONFINED between two electrodes having unit cross SECTIONAL area and are SEPARATED by a unit distance. Unit of resistivity is Ohm metre `(Omega` m). |
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| 10. |
Define resistance or specific resistance and write a note on it. |
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Answer» Solution :* "The electrical resistance of any object is DIRECTLY PROPORTIONAL to its length L and inversely proportional to its area of cross section A". `R prop(l)/(A)` `therefore R=rho((l)/(A)) and rho=R((A)/(l))` * Unit : SI unit of resistance is ohm meter `(Omegam)` and some times it will be ohm centimetre `(Omegacm)`. Note : IUPAC recommends the USE of the term resistivity over SPECIFIC resistance. * In short, resistivity means resistance. SI unit of `rho=R((A)/(l))""|Where, A=1m^(2)"",l=1m, R=rho` `=((Omega)(m)^(2))/(m)=Omegam` `1Omegam=100Omegacm` `1Omegacm=0.01Omegam` |
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| 11. |
Define resistivity. |
| Answer» Solution :RESISTIVITY is defined as the resistance of an electrolyte confined between to electrodes having unit CROSS SECTIONAL area and are separated by a unit distance. The ratio `(l/A)` is called the CELL constant, Unit of resistivity is OHM metre `(Omegam)`. | |
| 12. |
Define resistance. Give its mathematical expression. |
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Answer» Solution :The RESISTANCE of such an electrolytic solution is also DIRECTLY propotional to the LENGTH (l) and inversely PROPORTIONAL to the cross sectional AREA (A). `"R "alpha" "l/A` `"R "alpha" "rhol/A` |
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| 13. |
Define : Rate of reaction and rate constant. |
| Answer» Solution :Rate of reaction is defined as the CHANGE in the concentration of any ONE of the reactants or products per unit time. Rate CONSTANT of a reaction is equal to the rate of reaction when concentration of each REACTANT is taken as `1" mol L"^(-1)`. | |
| 14. |
Define rate of a reacion. |
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Answer» Solution :it is DEFINED as the change in concentration of REACTANT (or product) in a PARTICULAR time interval i.e., RATE of REACTION `= ("Change in concentration")/("Time taken")` |
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| 15. |
Define rateof reaction . |
| Answer» SOLUTION :It is DEFINED as the RATE of formation of one or more of its PRODUCTS or as the rate of consumption of one or more of its reactants. | |
| 16. |
Define rate of a reaction. Write two factors that affect the rate of a reaction. |
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Answer» <P> Solution :Rate of a REACTION may be defined on the change in CONCENTRATION of a reactant or a product occurring in a unit time.Rate `= -(Delta[R])/(Deltat)= +(Delta[P])/(Deltat)` TWO factors that affect the rate of a reaction are : 1. Nature of the reactants.2. TEMPERATURE. |
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| 17. |
Define Rate law and Rate constant. |
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Answer» Solution :(i) Ratelaw : The expression in which reaction rate is given in TERMS of molar concentration of the reactants with each term raised to some POWER, which may not be same as the Stoichiometric coefficient of the reacting species in a balanced chemical equation. `xA +yB rarr "products"` `"Rate=k[A]^(m)[B]^(N)` `k="Rate constant"` (ii) Rate constant : For a INVOLVING the reactants A and B, Reaction rate `=k[A]^(m)[B]^((n)` The constant k is called rate constant of the reaction. If `[A]=1M and [B]=1M`, Reaction rate = k Thus, the rate constant (k) of a reaction is equal to the rate of reaction when the concentration of each reactant is equal to `"1 mol L"^(-1)` The change in the concentration of reactant or product per unit time under the condition of unit concentration of all the reactant. |
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| 18. |
Define Raoult’s law of binary solution containing non-volatile solute init. |
| Answer» SOLUTION :At a GIVEN TEMPERATURE, the vapour pressure of a solution containingnon-volatile SOLUTE is directly proportional to the mole FRACTION of the solvent. | |
| 19. |
Define rate constant. What is pseudo first order reaction? Explain with one example. |
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Answer» Solution :Rate constant : The rate constant of a chemical reaction is defined as the rate of the chemical reaction when the concentration (or active masses) of each reactant has unit value, i.e., 1 mol the case of solution and the pressure is 1 atm in case of gases. Pseudo first ORDER reaction : A reaction which has higher order true rate LAW but experimentally found to behave as first order is called pseudo first order reaction. Explanation : Consider an ACID hydrolysis reaction of an ester like methyl acetate. `CH_(3)COOCH_(3_((AQ)))+H_(2)O_((l)) overset(H_((aq))^(+))to CH_(3)COOH_((aq))+CH_(3)OH_((aq))` Since the reaction involves two substances, ester and water, it is a bimolecular reaction and the true rate law should be, `"Rate"=k'[CH_(3)COOCH_(3)]xx[H_(2)O]` Hence the reaction is expected to have second order kinetics. However experimentally it is found that the reaction follows first order kinetics. This is because solvent water being a large excess, its concentration remains constant. Hence,`[H_(2)O]="constant"=k"` `"Rate"=k'[CH_(3)COOCH_(3)]xx[H_(2)O]` `=k'[CH_(3)COOCH_(3)]xxk''` `=k'xxk''xx[CH_(3)COOCH_(3)]` iF `k'xxk''=k`, then Rate= `k[CH_(3)COOCH_(3)]`. This indicates that Pecond order true rate law is forced into first order rate law. Therefore this bimolecular reaction which APPEARS of second order is called pseudo first order reaction. |
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| 20. |
Define rate constant of reaction. |
| Answer» SOLUTION :Rate constant : It is the rate of chemical reaction when the concentration ofreactant taken as UNITY at a given TEMPERATURE. | |
| 21. |
Define radius ratio. Give the limiting radius ratio value for a co-ordination number of 6. |
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Answer» Solution :Radius ratio is defined as the ratio of the radius of the CATION to that of ANION in any ionic CRYTAL. OR Radius ratio`= (r_+)/(r_-)` Where `r_+and r_-` are ratio of cation and anion RESPECTIVELY . 0.414 to 0.732 . |
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| 22. |
Define radius ratio what is the co-ordination number, if the radius ratio in a compound is 0.52 ? |
| Answer» SOLUTION :It is the ratio of the radius of the cation to the radius of the ANION. The co-ordination NUMBER of the COMPOUND is 6. | |
| 23. |
Define radius ratio. |
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Answer» Solution :Ratio of RADIUS of CATION to the radius of ANION. OR Radius ratio `= (R^(+))/(r^(-))` `r^(+)` = radius of cation `r^(-)` = radius of anion. |
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| 24. |
Define racemic mixture. Give IUPAC name of CH_(3)-CH_(2)-overset(CH_(3))overset(|)(CH)-CHO |
| Answer» Solution :A solution in which both enatiomers of a compound are present in equal AMOUNTS is called a racemic mixture, or recemate. Racemic mixtures can be symbolised by a `(d//l)-or (pm)-` prefix in front of the substance's name indicating an equal (1:1) mixture of extro and laevo isomers. Also the prefix rac-(or RACEM-) or the symbols RS and SR (all in italic LETTERS) are used. Since enantiomers have equal and opposite SPECIFIC rotations, a racemic mixture EXHIBITS no optical activity. Therefore, it is impossible to tell a racemic mixture apart from an achiral substance using polarimetry alone. The process by which a racemic mixture is formed from chiral materials is called recemisation. The separation of a racemate into its components, the pure enantiomers, is called a chiral reasolution. IUPAC name of compound is 2-methylbutanal. | |
| 25. |
Define 'peptization'. |
| Answer» Solution : It is defined as the PROCESS of converting a precipitate into colloidal sol on shaking with dispersion MEDIUM in the PRESENCE of an electrolyte. | |
| 26. |
Define peptization. |
| Answer» SOLUTION :It is the process of passing of precipitates into colloidal solution by adding a SUITABLE electrolyte. For example, a REDDISH brown positively charged sol is prepared by adding a SMALL quantity of `FeCl_3`to a freshly prepared precipitate of `Fe(OH)_3` . | |
| 27. |
Define peptisation. |
| Answer» SOLUTION :SEE DIFINITION on PAGE | |
| 28. |
Define oxidation and reduction from an organic perspective and give specific examples. |
Answer» Solution :Oxidation: A carbon atom is oxidized when there is an increase in the number of BONDS between that carbon and the atoms that are more ELECTRONEGATIVE than carbon, usually oxygen. For example, the indicated carbon atom is oxidized because the number of bonds between carbon and oxygen is INCREASED from one to two.  Reduction: A carbon atom is reduced when there is an increase in the number of bonds between that carbon and the atoms that are less electronegative than carbon, usually HYDROGEN. For example, the indicated carbon atoms are reduced because the number of bonds between car BON and hydrogen is increased from zero to two. 
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| 29. |
Define osmotic pressure. Prove that osmotic pressure is a colloigative property. |
| Answer» SOLUTION :For ANSWER CONSULT SECTION 12. | |
| 30. |
Define osmotic pressure. How does it depend upon the temperature and atmospheric pressure ? |
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Answer» SOLUTION : Osmotic pressure `(pi )` may be defined as : The additional pressure which gets exerted on the solution due to the osmosis of pure solvent into it through a semi permeable membrane. Or The extra pressure which has to be applied on the surface of the solution to CHECK the osmosis of pure solvent into it.(i) Osmotic pressure ALWAYS increases with the RISE in temperature because according to vant Hoff equation `pi` = CRT. (II) The osmotic pressure increases with the increase in atmospheric pressure because as the atmospheric pressure increases, there is a greater tendency of the solvent molecules to pass into the solution through the semi-permeable membrane thereby causing an increase in osmotic pressure. |
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| 31. |
Define osmosis and osmotic pressure and show that osmotic pressure is a colligative property. |
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Answer» Solution :OSMOSIS and osmotic PRESSURE. Refer to brief review. Osmotic pressure `(pi)` for a DILUTE solution is given as `pi prop (n_B )/(V )`(At constant temperature) ` n_B= N o.` of moles of solute V = Volume of solution or volume of solvent because solution is dilute. ` thereforepi` depends UPON no. of moles of solute dissolved in a given amount of solvent and is independent of nature of solute particles, `THEREFORE` it is a colligative property. |
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| 32. |
Define osmotic pressure. |
| Answer» Solution :EXTERNAL pressure to be applied on the solution SIDE just to stop the flow SOLVENT from its side to solution side across Semipermeable membrane. | |
| 33. |
Define osmosis. |
| Answer» Solution :"Osmosis is defined as the FLOW of SOLVENT molecules from the solution of lower CONCENTRATION to the solution of higher concentration, when they are SEPARATED by mens of a SEMIPERMEABLE membrane." | |
| 34. |
Define order of reaction. Write the condition under which a bimolecular reaction follows first order kinetics. |
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Answer» Solution :The sum of powers of the CONCENTRATION terms of reactants in the rate LAW expression is called the ORDER of that chemical reaction. In a biomolecular reaction, when one of the components is TAKEN in LARGE excess, its concentration does not change. Under such conditions, the bimolecular reaction follows first order reaction. |
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| 35. |
Define order of reaction. |
| Answer» Solution :It is the number of concentration TERMS which DETERMINES the DEPENDENCE of rate of REACTION. | |
| 36. |
Define order of chemical reaction. |
| Answer» Solution :order of a CHEMICAL reaction is the SUM of powers of Concentration TERMS INVOLVED in the the experimentally determined that law. | |
| 37. |
Define 'order of a reaction'. |
| Answer» SOLUTION :Order of Reaction : It is the SUM of powers to which the conc. terms areraised in rate LAW EXPRESSION | |
| 38. |
Define "Order of a reaction". |
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Answer» SOLUTION :The SUM of powers of exponents to which the CONCENTRATION TERMS are raised in the rate law expression. order of a reaction = m+n `mA + nB rarr` products Rate of a reaction `= K[A]^(m)[B]^(n)` |
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| 39. |
Define nucleotide. |
| Answer» Solution :Nucleotides are MONOMERS of nucleic acid, They CONSIST of heterocyclic base, PENTOSE sugar and PHOSPHORIC acid RESIDUE. | |
| 40. |
Define normal salt. |
| Answer» Solution :It is a compound which is formed by the complete NEUTRALISATION of a strong acid by a strong BASE. EXAMPLE : `NACL, KC1, K_2SO_4, MgSO_4` etc. | |
| 41. |
Define mutarotation. |
| Answer» Solution :When pure form any one of these SUGARS dissolved in water, slow interconversion of `alpha`-D glucose and `^(2)-D` glucose VIA OPEN chain form until equilibrium is established GIVING constant specific rotation specific rotation `+ 53^(@)`. This phenomenon is called mutarotation. | |
| 42. |
Define Molefraction and Mass percentage. |
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Answer» Solution :Mole &action is the ratio of the no. of moles o.f solute to the TOTAL no, of moles of all the components PRESENT in the solution. Molefraction of solute = `("No. of moles of solute")/("Total no.of moles of all the components ") ` `X_(A) = (n_(A))/(n_(A) + n_(B))` ` X_(B) = (n_(B))/(n_(A) + n_(B)) ` Mass Percentage : Mass Percentage is the mass of solute per 1000 g of solution. Mass percentage of solute `= ("Mass of solute")/("Mass of solution"). xx 100.` |
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| 43. |
Define molecularity of a reaction. |
| Answer» Solution :Number of REACTING SPECIES SIMULTANEOUSLY TAKING PART in collision in a single step of the chemical reaction is called molecularity. | |
| 44. |
Define 'molecularity of a reaction'. |
| Answer» SOLUTION :SEE DEFINITION on PAGE`4//19`. | |
| 45. |
Define mole fraction of a substance in a solution |
| Answer» SOLUTION :It is the ratio of the number of moles of the solute to the TOTAL number of moles of the solute and SOLVENT. | |
| 46. |
Define mole fraction . |
| Answer» SOLUTION :The mole FRACTION `(X_A)` of acomponent (A) is the ratio of numder of moles component (A) to the TOTAL number of moles of all the COMPONENTS . | |
| 47. |
Define molarity and molality. |
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Answer» Solution :(i) Molarity is the NUMBER of moles of solute dissolved in one LITRE of the solution. Molarity (M) = `("Moles of solute")/("volume of solution in litre")` (ii) Molality is the no. of moles of the solute per kilograms of the solvent . Molality (m) = `("Moles of solute ")/("Mass of the solvent in KG ")` . |
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| 48. |
Define the term 'Molarity'. |
| Answer» SOLUTION :NUMBER of MOLES of solute in one DM of solution is called MOLARITY. | |
| 49. |
Define molar conductivity of a substance and describe how for weak and strong electrolytes, molar conductivity changes with concentration of solute. How is such change explained ? A voltaic cell is set up at 25 °C with the following half-cells : Ag^+ (0.001 M) | Ag and Cu^(2+) (0.10 M) | Cu What would be the voltage of this cell ? [E_("cell")^(@)= 0.46 V] |
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Answer» Solution :(a) Molar conductivity may be defined as the conductance of all the ions at dilution V PRODUCED when one mole of the electrolyte is dissolved in V `cm^(3)`of the solution, the distance between the electrolytes being 1 cm. CHANGE of molar conductivity with concentration : Molar conductivity increases sharply for weak electrolytes with decrease in concentration as shown in the diagram because number of ions as well as mobility of ions increases with dilution. In CASE of strong electrolytes, `Lambda_(m)` increases slightly on dilution because number of ions do not INCREASE much whereas mobility of ions increases. (b)Cell reactions may be written as: `Cu(s) to Cu^(2+) (aq) + 2e^(-)` `2Ag^(+)(aq) + 2e^(-) to 2Ag(s)` -------------------------------------------- `Cu(s) + 2Ag^(+)(aq) to Cu^(2+) (aq) + 2Ag(s)` Thus, n=2 Using Nernst equation and substituting the values, we have: `E_("cell") = E_("cel")^(@) -0.591/2 log ([Cu^(2+)])/([Ag^(+)]^(2)) = 0.46 - 0.0591/2 log 0.1/(0.001)^(2)` or `E_("cell") = 0.46 - 0.0295 XX 5 = 0.3125` V |
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| 50. |
Define molar conductivity. How is it related to the specific conductivity? |
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Answer» Solution :Conductivity due to all the ions PRODUCED from one mole of the ELECTROLYTE at the GIVEN concentration and temperature is called molar conductivity. `A=k TIMES v` (Upper case) |
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