94420 + Interview Questions in Chemistry in Class 12 Page 577 InterviewSolution

28801.	What is the function of a salt bridge?
Answer» To allow IONS to go from one cell to another To PROVIDE link between two HALF cells To KEEP the emf of the cell positive To MAINTAIN electrical neutrality of the solution in two half cells Answer :D

Discussion

28802.	The main function of roasting is :
Answer» To REMOVE the VOLATILE matter Oxidation Reduction To MAKE slag Answer :B

Discussion

28803.	The main force(s) which stabilise the 2^@ and 3^@ structures of proteins is/are
Answer» hydrogen BONDS disulphide linkages van der WAALS' and electrostatic forces of attraction All of the above Solution :The MAIN forces which stabilise the `2^@` and `3^@` . structures of proteins are hydrogen bonds, d1sulph1de linkages, van der Waals' and electrostatic forces of attraction.

Discussion

28804.	The main factors which affect corrosion are:
Answer» position of METAL in electrochemical series presence of `CO_(2)` in water presence of IMPURITIES in metal preence of PROTECTIVE coating Answer :A::B::C::D

Discussion

28805.	The main factor (s) which affect corrosion is/are
Answer» POSITION of metl in electrochemical series presence of `CO_(2)` in water presence of IMPURITIES in metal presence of protective coating Solution :a,C,d

Discussion

28806.	The main function of haemoglobin is to :
Answer» help in muscular MOVEMENT. STORE OXYGEN until it is needed for reproduction. catalyse biochemical processes. transport oxygen from lungs to various TISSUES through BLOOD stream. Answer :D

Discussion

28807.	The main factor responsible for weak acidic nature of B-F bonds in BF_(3) is :-
Answer» LARGE electronegativity of F Three CENTRED two electron BONDS in `BF_(3)` `p pi-d pi` BACK BONDING `p pi-p pi` back bonding Answer :D

Discussion

28808.	The main factor responsible for weak acidic nature of B-F bonds in BF_3 is :
Answer» Large electronegativity of F Three CENTRED two electron bonds in `BF_3` `ppi-dpi` back BONDING `ppi-ppi` back bonding Answer :D

Discussion

28809.	The main factor of shorter B-F bonds in BF_(3) is :
Answer» LARGE electronegativity of fluorine three-centred TWO electron bonds in `BF_3` `p pi = p pi` back bonding `p pi - d pi` back bonding ANSWER :C

Discussion

28810.	The main difference between conventional electro-chemical cell and fuel cell is the materials undergoing oxidation at the anode or reduction at the cathode in fuel cell
Answer» are not STORED are stored INSIDE the cell are stored OUTSIDE the cell reactions at ANODE and cathode Solution :Storage of `H_(2) "and" O_(2)` is outside.

Discussion

28811.	The main difference between bathing and washing soap is
Answer» bathing SOAP are potassium salts of FATTY acids washing soaps are SODIUM salt of fatty acids . bathing soaps are sodium salt of fatty acids while washing soapsare potassium salt of fatty acids bathing soaps are cationic in nature while washing soaps are anionic bathing soaps are calciumsalts of fatty acids while washing soapsare anionic ANSWER :A

Discussion

28812.	Themain cuplrit for the depletion of protective ozonelayer is
Answer» OXYGEN CFCS OXIDES of S Particulatematter. ANSWER :B

Discussion

28813.	The main couse of acidity in the stomach is
Answer» release of extra gastric acids which decrease the pH LEVEL indigestion and PAIN in LARGE intestine increase the pH level in the stomach release of extra bile JUICE which increases ALKALINE medium in stomach. Answer :A

Discussion

28814.	How is acid rain caused ?
Answer» `H_(2) SO_(4)` `CaCO_(4)` `CH_(3)COOH` `PAN` Answer :A

Discussion

28815.	The main constituents of dettols are
Answer» CHLORAMPHENICOL + glycerol 2-3% solution of IODINE in alcohol 0.2% solution of PHENOL. CHLOROXYLENOL and terpineol. Answer :D

Discussion

28816.	The main constituents of coal gas are :
Answer» `CH_4+CO+H_2` `CO_2+CO+H_2` `CO+CO_2` `CO+N_2` ANSWER :A

Discussion

28817.	The main constituent of steel in india are:
Answer» NI and Mg V andCo Al and Zn Mn and Cr Answer :D

Discussion

28818.	The main constituent of most natural fibres is
Answer» GLYCOGEN STARCH CELLULOSE all of these ANSWER :C

Discussion

28819.	The main constituent of egg-shells is:
Answer» `CaCO_3` `CaSiO_3` `CaSO_41/2H_2O` `CaSO_42H_2O` ANSWER :A

Discussion

28820.	The main constituent of bones is:
Answer» `CaCO_3` `CaF_2` `CaSO_4` `Ca_3(PO_4)_2` ANSWER :D

Discussion

28821.	The main component/compounds provided by crushed grapes for wine making is/are
Answer» sugars sugars and yeast sugars and tartaric acid sugars, yeast and tartaric acid. Solution :The two most IMPORTANT components NEEDED for fermentation, sugars (in the fruit juice) and yeast (present on the SKIN of grapes). Both of these are provided by crushed groups.

Discussion

28822.	The main cause of acidity in the stomach is
Answer» releaseof EXTRA gastric acidswhich decrease the pH level indigestionand pain in larger intestine increase the pH level in the STOMACH releaseof extra bile juice which INCREASES alkaline MEDIUM in stomach . ANSWER :A

Discussion

28823.	The main cause of depression is
Answer» LOW LEVEL of noratronaline high livel of noradronaline low livel of HCI in stomach high livel of HCI in stomach ANSWER :A

Discussion

28824.	The main application of osmotic pressure measurement is in the determination of the molar mass of a substance which is either slightly soluble or has a very high molar mass such as proteins, polymers of various types and colloids.This is due to the fact that even a very small concentraion of the solution produces fairly large magnitude of osomotic pressure.In the laboratory the concentrations usually employed are of the order of 10^(-3) to 10^(-4) M.At concentration of 10^(-3) mol dm^(-3) , the magnitude of osmotic pressure of 300 K is : P=10^(-3)xx0.082xx300=0.0246 atm or 0.0246xx1.01325xx10^5=2492.595 Pa At this concentration, the values of other colligative properties such as boiling point elevation and depression in freezing point are too small to be determined experimentally. Further polymers have following two types of molar masses : (A) Number average molar mass (barM_n), which is given by (undersetisumN_iM_i)/(undersetisumN_i) where N_i is the number of molecules having molar mass M_i. (B) Molar average molar mass (barM_m), which is given by (undersetisumN_iM_i^2)/(undersetisumN_iM_i) Obviously the former is independent of the individual characteristics of the molecules and gives equal weightage to large and small molecules in the polymer sample.On the other hand later gives more weightage to the heavier molecules.Infact with the help of a colligative property only one type of molar mass of the polymer can be determined. What will be the observed molecular weight of the above polymer sample generating osomotic pressure equal to the answer in the previous questions at 27^@C?
Answer» 4000 3000 2500 1200 Solution :`0.0164xx1=2/mxx0.082xx300` `:. M=3000`

Discussion

28825.	The main application of osmotic pressure measurement is in the determination of the molar mass of a substance which is either slightly soluble or has a very high molar mass such as proteins, polymers of various types and colloids.This is due to the fact that even a very small concentraion of the solution produces fairly large magnitude of osomotic pressure.In the laboratory the concentrations usually employed are of the order of 10^(-3) to 10^(-4) M.At concentration of 10^(-3) mol dm^(-3) , the magnitude of osmotic pressure of 300 K is : P=10^(-3)xx0.082xx300=0.0246 atm or 0.0246xx1.01325xx10^5=2492.595 Pa At this concentration, the values of other colligative properties such as boiling point elevation and depression in freezing point are too small to be determined experimentally. Further polymers have following two types of molar masses : (A) Number average molar mass (barM_n), which is given by (undersetisumN_iM_i)/(undersetisumN_i) where N_i is the number of molecules having molar mass M_i. (B) Molar average molar mass (barM_m), which is given by (undersetisumN_iM_i^2)/(undersetisumN_iM_i) Obviously the former is independent of the individual characteristics of the molecules and gives equal weightage to large and small molecules in the polymer sample.On the other hand later gives more weightage to the heavier molecules.Infact with the help of a colligative property only one type of molar mass of the polymer can be determined. One gram each of polymer A (molar mass=2000) and B(molar mass=6000) is dissolved in water to form one litre solution at 27^@C.The osmotic pressure of this solution will be :
Answer» 0.0164 ATM 1862 PA Both are CORRECT NONE of these Solution :`Pxx1=(1/2000+1/6000)xx0.082xx300` `:.` P=0.0164 atm

Discussion

28826.	The main bonding responsible for blockgae of enzyme is
Answer» HYDROGEN BOND ionic bond VAN der Waals attractions strong COVALENT bond Answer :D

Discussion

28827.	The main agent for polluting the environment is
Answer» gas plant ANIMAL man. Solution :animal

Discussion

28828.	The magnitude of work done (in kcal) when 120 gm of Mg (s) is reacted with excess of hydrochloric acid in an open vessel at 27^@C is
Answer» Solution :MAGNITUDE of W=3 kcal `Mg(s)+2HCL(AQ)toMgCl_2(s)+H_2(G)uarr` `W= -P_(ed)(V_2-V_1)= -Deltan_(g)RT= - 5XX(2xx300)/1000=-3` kcal

Discussion

28829.	The magnitude of work done by a gas that undergoes a reversible expansion alog the path ABC shown in the figure is __________.
Answer» ANSWER :62

Discussion

28830.	The magnitude of work done by a gas is a reversible expansion is greater than that in an irreversible expansion provided the initial and final state are identical in both processes-explain.
Answer» Solution :Suppose, an ideal gas expands isothermally from its initial state `P_(1) V_(1)` to final state `P_(2)V_(2)`. A reversible process consists of an infinite number of small steps, and at each STEP, the driving from is infinitesimally greater than the OPPOSING force. suppose, in a reversible expansion of an ideal gas, the external pressure of the gas at a step of the process is decreased by a very small amount dP, CAUSING the increase in VOLUME of the gas by dV. the work done by the gas will be, dw=`-(P_(ex)-dP)dV=-PdV`[`becauseP_(ex)-dP=P` (Pressure of the gas) and `dPxxdV` is very small as in the P-V diagram the point, m and n are very close and pressure in these two points are not much different]. in the above diagram, PdV is givenn by the area of the strip, mnqp. total work done in reversible process will be equal to the sum of the areas of all such strips. thus, in such a process, work done, `-w=underset(V_(1))overset(V_(2))intPdV=`area ABNM Absolute value of work done, `\|w\|=` area ABNM Now, in isothermal irreversible expansion, suppose, the gas is expanded from volume`V_(1)` to `V_(2)` against an external pressure which is equal to the final pressure of the gas. in this process work done, `w=underset(V_(1))overset(V_(2))intP_(2)dV=-P_(2)underset(V_(1))overset(V_(2))intdV` [`P_(2)=`constant during expansion] Absolute value of work done, `\|w\|=(V_(2)-V_(1))`=area. ABNE. From the graphs, it is clear than work done is reversible isothermal expansion is greater than that in irreversibleisothermal expansion, since the arae of ABNM is greater than that of ABNE. this also indicates that work involved in a process depends UPON the path (or nature) o the process.

Discussion

28831.	The magnitude of thelattice enthalpy of a solidincreases if-
Answer» the IONS are large the ions are small the ions are of EQUAL SIZE CHARGES on the ions are small Answer :B

Discussion

28832.	The magnitude of spin angular momentum of an electron is given by
Answer» `s=sqrt(s(s+1))` `s=sxxh/(2pi)` `s=(sqrt(3))/2xxh/(2pi)` `s=+-1/2xxh/(2pi)` SOLUTION :SPIN angularmomentum `=sqrt(s(s+1))H/(2pi)` ALSO `s=sqrt(1/2(1/2+1))xxh/(2pi)=(sqrt(3))/2xxh/(2pi)`

Discussion

28833.	The magnitude of crystal stabilization energy (CFSE or Delta_(t)) in tetrahedral complexes is considerably less than in the octahedral field. Because
Answer» There are only four ligands instead of six so the ligand field is only 2/3 the size hence the `Delta_(t)` is only 2/3 the size The direction of the ORBITALS does not coincide with the direction of the ligands. This reduces the CRYSTAL field stabilization energy `(Delta_(t))` by further 2/3 Both points (a) and (b) are correct Both points (a) and (b) are wrong Solution :CFSE in case of TETRAHEDRAL complexes is less than the OCTAHEDRAL field due to the points (a) and (b).

Discussion

28834.	The magnitude of crystal field stabilisation energy in octaheral field depends on: (I) the nature of the ligand (II) the charge on the metal ion. (III) whether the metal is in the first, second or third row of the transition elements
Answer» I, II, III only correct I, II only correct II, III only correct III only correct Answer :A

Discussion

28835.	The magnitude of crystal field stabilization energy (CFSE or Deltat) in tetrahedral complexes is considerably less than in octahedral field. This is because
Answer» There are FOUR ligands instead of six so the ligand field is only 2/3 the size hence , the `Delta`t is only 2//3 the size The direction of the orbitals does not coincide with the direction fo the ligands . This reduces the CRYSTAL field stabilisation ENERGY `(Deltat)` by further 2/3 Both points (A) and (B) correct Both points (A) and (B) are wrong . Solution :CFSE in case of tetrahedral complexes is less than the octahedral field due to both the points A and B.

Discussion

28836.	The magnitude of colligative properties in all colloidal dispersions is …..than solution
Answer» LOWER HIGHER Both NONE ANSWER :A

Discussion

28837.	The magnetic property, dipole moment, plane of symmetry, colour and absorption band cann be helpful in structure elucidation of complex compounds: Q. Complex compound() having even number of space (stereo) isomers is/are: (Where AA-symmetrical bidentate ligand ad a,b,c,d,e-monodentate ligands)
Answer» `[M(A A)_(2)b_(2)]^(n+-)` `[Ma_(3)b_(3)]n^(+-)` `[Ma_(3)BCD]^(n+-)` `[Ma_(2)bcde]^(n+-)` ANSWER :B

Discussion

28838.	The magnetic quantum number for valency electron of sodium is:
Answer» 3 2 1 Zero Answer :D

Discussion

28839.	The magnetic property, dipole moment, plane of symmetry, colour and absorption band cann be helpful in structure elucidation of complex compounds: Q. Compound 'x' has molecular formula CrCl_(2)Br*6H_(2)O can show type of isomerism. (i) hydrate isomerism (ii) ionization isomerism (iii) geometrical isomerism (iv) optical isomerism
Answer» (i), (II) and (III) only (i) and (ii) only (i), (ii), (iii) and (IV) (i) and (iii) only Answer :A

Discussion

28840.	The magnetic property, dipole moment, plane of symmetry, colour and absorption band cann be helpful in structure elucidation of complex compounds: Q. Which of the following complex ion is expected to absorb light in 4000 Å to 7800 Å region?
Answer» `[Ti(en)_(3)]^(4+)` `[CR(H_(2)O)_(6)]^(3+)` `[Sc(NH_(3))_(4)(H_(2)O)_(2)]^(3+)` `Zn(en)_(2)(NH_(3))_(2)]^(2+)` Answer :B

Discussion

28841.	The magnetic properties of oxygen and ozone are different. Explain.
Answer» SOLUTION :Oxygen is a MOLECULE with even number of ELECTRONS. But it is paramagnetic . Its magnetic moment is 2.83BM corresponding to two unpaired electrons. Molecular orbital THEORY explains the presence of unpaired electrons. Ozone is diamagnetic. Its magnetic moment is ZERO. Ozone molecule has no unpaired electrons.

Discussion

28842.	The magnetic properties of NO_(2) and N_(2)O_(4) are different. Why?
Answer» SOLUTION :`NO_(2)` MOLECULE has unpaired ELECTRON. Hence it is paramagnetic and reactive. `NO_(2)` dimerises to GIVE `N_(2)O_(4).N_(2)O_(4)` molecule has no unpaired electrons. Hence it is diamagnetic.

Discussion

28843.	The magnetic nature of elements drpends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
Answer» `3d^(7)` `3d^(5)` `3d^(8)` `3d^(2)` Solution :`d^(5)` has HIGHEST number of unapired electron. HENCE, it has highest MAGNETIC moment.

Discussion

28844.	The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements, which shows highest magnetic moment.
Answer» `3D^(7)` `3d^(5)` `3d^(8)` `3d^(2)` SOLUTION :`3d^(5)` has MAXIMUM unpaired electrons `( = 5)`.

Discussion

28845.	The magnetic ore is :
Answer» Fe3O4 Fe2O3 Fe(OH)3 FeCO3 Answer :D

Discussion

28846.	The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment ?
Answer» `3d^7` `3d^8` `3d^5` `3d^2` ANSWER :C

Discussion

28847.	The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element which shows highest magnetic moment.
Answer» `3d^7` `3d^5` `3d^8` `3d^2` Solution :CONFIGURATION `3d^5` is associated with maximum number of unpaired electrons (5) and thus has maximum MAGNETIC MOMENT.

Discussion

28848.	The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment?
Answer» `3d^7` `3d^5` `3d^8` `3d^2` Solution :The LARGER the number of unpaired electrons in a element, the greater is the paramagnetic character and larger is the magnetic MOVEMENT, this can be calculated from the relation. `MU = SQRT(N(n+2)) B.M` Where, n is the number of unpaired electrons and u is magnetic moment. `3d^(5)` contain highest unpaired electron so have highest magnetic moment.

Discussion

28849.	The magnetic moments of few transition metal ions are given below : {:("Metal ion",,,"Magnetic moment (BM)"),(Sc^(3+),,,0.00),(Cr^(2+),,,4.90),(Ni^(2+),,,2.84),(Ti^(3+),,,1.73):} (At. no. Sc = 21, Ti = 22, Cr = 24, Ni = 28) Which of the given metal ions : (i) has the maximum number of unpaired electrons ? (ii) forms colourless aqueous solution ? (iii) exhibits the most stable +3 oxidation state ?
Answer» Solution :(i) As `Cr^(2+)` SHOWS the maximum magnetic moment, it has the maximum number of unpaired electrons. (II) The configuration of `Sc^(3+)` ion is `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6)`. As all the ORBITALS are completely filled, there is no possibility of excitation of electrons. It forms a colourless AQUEOUS solution. (iii) Again because of completely filled orbitals, `Sc^(3+)` shows the most STABLE +3 oxidation state.

Discussion

28850.	The magnetic nature of elements depend on the presence of unpaired electrons. Identify the configuration of transition element,which shows highest magnetic moment.
Answer» `3d^7` `3d^5` `3d^8` `3d^2` ANSWER :B

Discussion

Explore topic-wise InterviewSolutions in .

What is the function of a salt bridge?

The main function of roasting is :

The main force(s) which stabilise the 2^@ and 3^@ structures of proteins is/are

The main factors which affect corrosion are:

The main factor (s) which affect corrosion is/are

The main function of haemoglobin is to :

The main factor responsible for weak acidic nature of B-F bonds in BF_(3) is :-

The main factor responsible for weak acidic nature of B-F bonds in BF_3 is :

The main factor of shorter B-F bonds in BF_(3) is :

The main difference between conventional electro-chemical cell and fuel cell is the materials undergoing oxidation at the anode or reduction at the cathode in fuel cell

The main difference between bathing and washing soap is

Themain cuplrit for the depletion of protective ozonelayer is

The main couse of acidity in the stomach is

How is acid rain caused ?

The main constituents of dettols are

The main constituents of coal gas are :

The main constituent of steel in india are:

The main constituent of most natural fibres is

The main constituent of egg-shells is:

The main constituent of bones is:

The main component/compounds provided by crushed grapes for wine making is/are

The main cause of acidity in the stomach is

The main cause of depression is

The main bonding responsible for blockgae of enzyme is

The main agent for polluting the environment is

The magnitude of work done (in kcal) when 120 gm of Mg (s) is reacted with excess of hydrochloric acid in an open vessel at 27^@C is

The magnitude of work done by a gas that undergoes a reversible expansion alog the path ABC shown in the figure is __________.

The magnitude of work done by a gas is a reversible expansion is greater than that in an irreversible expansion provided the initial and final state are identical in both processes-explain.

The magnitude of thelattice enthalpy of a solidincreases if-

The magnitude of spin angular momentum of an electron is given by

The magnitude of crystal stabilization energy (CFSE or Delta_(t)) in tetrahedral complexes is considerably less than in the octahedral field. Because

The magnitude of crystal field stabilisation energy in octaheral field depends on: (I) the nature of the ligand (II) the charge on the metal ion. (III) whether the metal is in the first, second or third row of the transition elements

The magnitude of crystal field stabilization energy (CFSE or Deltat) in tetrahedral complexes is considerably less than in octahedral field. This is because

The magnitude of colligative properties in all colloidal dispersions is …..than solution

The magnetic property, dipole moment, plane of symmetry, colour and absorption band cann be helpful in structure elucidation of complex compounds: Q. Complex compound() having even number of space (stereo) isomers is/are: (Where AA-symmetrical bidentate ligand ad a,b,c,d,e-monodentate ligands)

The magnetic quantum number for valency electron of sodium is:

The magnetic property, dipole moment, plane of symmetry, colour and absorption band cann be helpful in structure elucidation of complex compounds: Q. Which of the following complex ion is expected to absorb light in 4000 Å to 7800 Å region?

The magnetic properties of oxygen and ozone are different. Explain.

The magnetic properties of NO_(2) and N_(2)O_(4) are different. Why?

The magnetic nature of elements drpends on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements, which shows highest magnetic moment.

The magnetic ore is :

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment ?

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition element which shows highest magnetic moment.

The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment?

The magnetic nature of elements depend on the presence of unpaired electrons. Identify the configuration of transition element,which shows highest magnetic moment.