94420 + Interview Questions in Chemistry in Class 12 Page 1816 InterviewSolution

90751.	A colloid is formed by adding FeCl_3 in excess of hot water. What will happen if excess sodium chloride is added to this colloride ?
Answer» Solution :A positively CHARGED colloidal solution of hydrated ferric oxide is FORMED. On ADDING sodium chloride, NEGATIVELY charged chloride ions neutralise the positive charge of the colloidal solution. Coagulation of the sol takes place.

Discussion

90752.	(A) Colloidal particles show Brownian Movement(R ) Brownian movement arises because of the impact of the molecules of the dispersion medium with the colloidal particles.
Answer» Both (A) and (R ) are TRUE and (R ) is the correct EXPLANATION of (A) Both (A)and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is FALSE Both (A) and (R ) are false Answer :A

Discussion

90753.	A colloid is formed by adding FeCl, in excess of hot water. What will happen if excess sodium chloride is added to this colloid ? The
Answer» Solution :Adding excess `FeCl_(3)` to hot water produces COLLOIDAL solution of hydrated ferric oxide which is a POSITIVELY CHARGED COLLOID. When excess NaCl is ADDED, `Cl^(-)` will coagulate the colloidal sol.

Discussion

90754.	A colloid is formed by adding FeCL_(3) in excess of hot water. What will happen if excess of sodium chloride is added to this colloid ?
Answer» SOLUTION :On ADDING `FeCl_(3)` to WATER, a colloidal sol of hydrate ferric oxide is formed which carries +ve charge due to adsorption of `FE^(3+)` ions on its surface. On adding `NACL, Cl^(-)` ions bring about coagulation of the sol.

Discussion

90755.	A collision between high energy molecules overcomes the forces of repulsion and brings the formation of an unstable molecule cluster, called activated complex. The life span of an activatd complex is very small. Thus, the activated complex breaks either into reactants again or new substances, i.e. products. The activation energy (E_(a)) depends upon the nature of chemical bonds undergoing rupture and is independent of enthalpies of reactants and products. The energy changes during exothermic and endothermic versus the progress of the reaction are as shown below : When temperature is increased, the number of active molecule increases, i.e. the number of effective collisions will increase and the rate of reaction will increase. Activation energy (E_(a))=E_(("activated complex"))-E_(("ground state")) DeltaH=E_(a)(f)-E_(a)(b) The activation energy of exothermic reaction , A to B, is 80kJ. The heat of reaction is 200kJ. The activation energy for the reaction, B to A, will be
Answer» `80KJ` `120kJ` `280kJ` `200KJ` ANSWER :C

Discussion

90756.	A colloid always :
Answer» Contains two phases Is a true SOLUTION Contains THREE phases Contains only WATER soluble particles Solution :COLLOID is hetergeneous, biphasic solution.

Discussion

90757.	A collision between high energy molecules overcomes the forces of repulsion and brings the formation of an unstable molecule cluster, called activated complex. The life span of an activatd complex is very small. Thus, the activated complex breaks either into reactants again or new substances, i.e. products. The activation energy (E_(a)) depends upon the nature of chemical bonds undergoing rupture and is independent of enthalpies of reactants and products. The energy changes during exothermic and endothermic versus the progress of the reaction are as shown below : When temperature is increased, the number of active molecule increases, i.e. the number of effective collisions will increase and the rate of reaction will increase. Activation energy (E_(a))=E_(("activated complex"))-E_(("ground state")) DeltaH=E_(a)(f)-E_(a)(b) The activation energy for the forward reaction ,X to Y, is 60kJ mol^(-1) and DeltaH is -20kJ//mol^(-1), the activation energy for the reverse reaction is
Answer» `40kJ//mol` `60kJ//mol` `80kJ//mol` `20kJ//mol` ANSWER :C

Discussion

90758.	A cold, green flame can be made by passing CO_2 over warm:
Answer» Bonze White P Grey Sn Green candles Answer :B

Discussion

90759.	A codonhas a sequence of A, and specific a particular B that is to be incorporated into C. what are A,B,C
Answer» `{:("A","B","C"),("3 BASES","AMINO acid","carbohydrate"):}` `{:("A","B","C"),("3 acids","carbohydrate","protein"):}` `{:("A","B","C"),("3 bases","protein","amino acid"):}` `{:("A","B","C"),("3bases","amino acid","protein"):}` Answer :D

Discussion

90760.	A codon on the mRNA has :
Answer» ONE base Two base Three base Variable NUMBER of bases Answer :C

Discussion

90761.	A codon has a sequence of A and specifies a particular B that is to be incorporated into C what are ? A,B,C
Answer» A-3 bases, B-amino acid, C-carbohydrate A-3 acids, B-carbohydrate, C-protein A-3 bases, B-protien, C-amino acid A-3 bases, B-amino acid, C-protein Solution :A codon is a SPECIFIC SEQUENCE of three adjacent bases on a STRAND of DNA or RNA that provides GENETIC CODE information for a particular amino acid.

Discussion

90762.	(A) : CoCl_3 . 3NH_3 does not ionise in aqua solution. (R ): CoCl_3 . 3NH_3 is an example of aionic compounds.
Answer» Both A & R are true, R is the correct EXPLANATION of A Both A & R are true, R is not correct explanation of A A is true, R is false A is false, R is true Answer :C

Discussion

90763.	(A) : [Co_(2)(OH)_(3)(NH_(3))_(6)]Cl_(3) is an example of polynuclear complex compound (R) : Compound in which the number of central metal atoms is more than one is called polynuclear compound
Answer» Both A & R are TRUE, R is the CORRECT explanation of A Both A & R are true, R is not correct explanation of A A is true, R is false A is false, R is true Answer :A

Discussion

90764.	(A) : CO_(2) reacts with Grignard reagent followed by acid catalysed hydrolysis gives carboxylic acid . (R) : Alkyl halide reacts with Mg in the presence of ether gives Grignard reagent .
Answer» Both A & R are true , R is the correct explanation of A Both A & R are true , R is not correct explanation of A A is true , R is false A is false , R is true ANSWER :B

Discussion

90765.	A CO_2 molecule contains:
Answer» 2 `sigma-bonds` and 1 `pi-bond` 4 `pi-bonds` 2 `sigma` and 2 `pi-bonds` 4 `sigma-bonds` ANSWER :C

Discussion

90766.	A co -polymer ofvinyl chlorideand vinyledene chloride is called:
Answer» Dynel Saran Vinylon Oelen Answer :A

Discussion

90767.	A co -polymer ofvinyl chlorideand vinylidene chloride is called:
Answer» Dynel Saran Vinylon None of these Answer :A

Discussion

90768.	A co -polymer ofvinyl chlorideand vinyacetate is called:
Answer» Vinyon Saran Dynel Orlen Answer :A

Discussion

90769.	A co -polymer ofvinyl chlorideand vinyl acetate is called:
Answer» Vinyon PVCA Dynel Orlon Answer :A

Discussion

90770.	A co -polymer ofisobutylene and isoprene is called:
Answer» BUTYL rubber Buna -S Buna -N Thiokol Answer :A

Discussion

90771.	A co-polymer is one in which
Answer» two monomers undergo condensation there is excessive cross linking extensive HYDROGEN bonding REPEATING unit CONTAINS two different monomers Answer :D

Discussion

90772.	Assertion:Co-ordination compounds are generally formed by transition metals. Reason :Transition metals generally have partly filled d-orbitals in n^(th) shell.
Answer» Both A & R are true, R is the CORRECT explanation of A Both A & R are true, R is not correct explanation of A A is true, R is false A is false, R is true Answer :C

Discussion

90773.	A co-ordination complex has the formula PtCl_(4).2KCl. Electrical conductance measurement indicate the presence of three ion in one formula unit. Treatment with AgNO_(3) produces no precipitate of AgCl. What is the co-ordination number of Pt in this complex ?
Answer» 5 6 4 3 Solution :N//A

Discussion

90774.	A closed vessel with rigid walls contains 1 mole of ._(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ._(92)^(238)U to ._(82)^(206)Pbthe ratio of the final pressure to the initial pressure of the system at 298K is
Answer» ANSWER :9

Discussion

90775.	A closed vessel with rigid walls contains 1 mole of ""_(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ""_(92)^(238)U to ""_(82)^(206)Pb, the ratio of the final pressure to the initial pressure of the system at 298K is…..
Answer» SOLUTION :`""_(92)^(238)U RARR ""_(82)^(206)P + 8 ""_(2)^(4)He + 6 ""_(-1)^(0)e` `(P_("final"))/(P_("intial"))= (8 (He) + 1 ("air"))/(1("air"))`

Discussion

90776.	A closed vessel with rigid walls contains 1 mol of ._(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ._(92)^(238)U " to " ._(82)^(206)Pb, the ratio of the final pressure to the initial pressure of the system at 298 K is
Answer» Solution :Initial moles of gases = 1 `underset("Initial moles1 mole")(._(92)^(238)U rarr ._(82)^(206)Pb) + underset(8 "mole")(8_(2)^(4) He + 6 ._(-1)e^(0))` Moles after Total gaseous moles after decomposition `= 8 + 1 = 9` moles Ratio of pressures `(P_(f))/(P_(i)) = (n_(f))/(n_(i)) = 9`

Discussion

90777.	A closed vessel of known volume containing known amount of ideal gaseous substance 'A'was observed for variation of pressure with temperature .The expected graph was to be like as in ( i) However actual observations revealed the graph to be like. (ii) The deviation was attributed to polymerisation of gas molecules as nA(g) 1 A_(n) (g).If it is known that the above reactiongives only 50% yield. (a) Calculate the ratio of ( n_("experiment"))/( n_("theoritical")) ( where n_("exp.")= Total no. of gaseous mole actually present n_("theoretical") = Total no. of mole origianl taken ) ( b) Find the value of n to which the gas A is being polymerised into
Answer» ANSWER :(a) 0.625 (B) 4

Discussion

90778.	A closed vessel of known volume containing known amount of ideal gaseous substance 'A' was observed for variation of pressure with temperature . The expected graph was to be like as in (i) However actual observations reveal the graph to be like (ii). The deviation was attributed to polymerisation of gas molecules as nA(g)hArrA_(B)(g).If it is known that the above reaction given only 50% yield Find the value of n to which the gas A is being polymerised into
Answer» Solution :`nArArrA_(N) V=` constant `t=t_(eq)` moles `a_(0)-a_(0)alpha (a_(0)alpha)/(n)` ideal gases:- PV-nRT `P=(nR)/(V)(t^(@)+273)` `PV_(s)t(.^(@)C) y=mx+C`where `m=(nR)/(V)` `(m_("actual"))/(m_("theoriticl"))=(n_("actual"))/(n_("theortical"))=(a_(0)a_(0)alpha+(a_(0)alpha)/(n))/(a_(0))=(1.0375)/(1.66)=(1)/(1.6)` `(0.5xx1.6)/(n)=0.2` n=4

Discussion

90779.	A closed system undergoes a process AtoB. If it occurs reversible, then the system absorbs q_(1) amount of heat and performs w_(1) amount of work. However, if it occurs out irreversible, then the system absorbs q_(2) amount of heat and does w_(2) amount of work. is (q_(1)+w_(1)) greater than, less than or equal to (q_(2)+w_(2)) ?
Answer» SOLUTION :For a reversible process: `DeltaU_(1)=q_(1)+w_(1)` and for an irreversible process: `DeltaU_(2)=q_(2)+w_(2)`. In both processes, the initial state (A) and final state (B) of the system are identical. Since U is a state function, its change in a process depends only on the initial and final STATES of the system, and not on the NATURE of the process. as the initial and final states in both processes are identical, the change in INTERNAL energy in both cases will be the same. therefore, `DeltaU_(1)=DeltaU_(2)` and `q_(1)+w_(1)=q_(2)+w_(2)`.

Discussion

90780.	A closed flask contains water in all its three states, solids, liquid and vapour at 0@C. In this situation the average KE of the water molecule will be:
Answer» MAXIMUM in VAPOUR state Maximum in SOLID state Greater in the LIQUID than in vapour state Same in all the THREE states Answer :D

Discussion

90781.	A closed cylinder contains 40 g of SO_3 and 4 g of helium gas at 375 K. If the partial pressure of helium gas is 2.5 atm, then the volume of the container is (R = 0.082 L-atm K^-1 mol^-1)
Answer» 8.3 L 2.5 L 15.5 L 12.3 L Answer :D

Discussion

90782.	A clock spring is heated to redness and then plunged into cold water. This treatment will cause it to become
Answer» SOFT and ductile More SPRINGY than before Strongly magnetic Hard and brittle Answer :D

Discussion

90783.	A clock spirng is heated to a high temperature and then suddenly pluged into cold water . This treatment will cause the metal to becone :
Answer» SOFT and DUCTILE More SPRINGY than before HARD and brittle Strongly magnetic Answer :C

Discussion

90784.	A clear solution is heated in a china dish where upon a solid separates from the hot solution. It is due to the fact that
Answer» the SOLID has a positive enthalpy of solution the solid has a NEGATIVE enthalpy of solution solvent has evaporated the solute is volatile. Solution :(a) If the solid has positive enthalpy of solution its solubility will DECREASE with INCREASE in temperature and the solid will SEPARATE out on heating . The solid can also separate out on the evaporation of the solvent.

Discussion

90785.	A clathrate is defined as:
Answer» CAGE Compound Liquid crystal Mixture Solid solution Answer :A

Discussion

90786.	A class of drugs useful to inhibit the pathogenic action of microbes are called.
Answer» Antimicrobials Analgesic Antipyretics Tranquilizers Answer :A

Discussion

90787.	(A): Cl - O bond length decreases from CIO^(-) to ClO_(4)^(-) (R): CI-O bond order increases from CIO^(-) to CIO_(4)^(-).
Answer» Both (A) and (R ) are TRUE and (R ) is the correct EXPLANATION of (A) Both (A) and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is FALSE Both (A) and (R ) are false Answer :A

Discussion

90788.	(A) cis-2-butene overset(HCO_3H)rarrI (B) trans-2-butene overset(HCO_3H)rarrII Correct statements are
Answer» II is racemic MIXTURE by ANTI ADDITION II is MESO compound by anti addition I is meso compound by syn addition II is racemic compound by syn addition Answer :C::D

Discussion

90789.	(a) Cis-1,2-cylopentanediol reacts with acetone in the presence of dry HCl of yield compound K, C_(8)H_(14)O_2, which is resistance to boiling alkali, but which is readily into the starting material by aqueous acdis. What is structure of K ? (b) Trans-1,2-Cyclopentanediol does not form an analgous compound. explain why
Answer» Answer :`(##RES_CHM_CCAK_E01_003_A01##)` (B) The-OH groups in the trans ISOMER are too far part to form cyclic STRUCTURE

Discussion

90790.	A current of 2 ampere was passed through solution of CuSO_4 and AgNO_3 in series.0.635 g of copper was deposited .Then the weight of silver deposited will be:
Answer» 0.59g 3.24g 1.08g 2.16g Answer :D

Discussion

90791.	A chocolate brown coloured compound with acetic acid and potassium ferrocyanide is obtained from a salt solution containing :
Answer» Cu Cd Sn Hg Answer :A

Discussion

90792.	(A) Chromates and dichromates are not interconvertible in aqueous solution with charge in pH. (R) Chromates are orange in colour.
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is FALSE Both (A) and (R) are false Solution :Both (A) and (R) are false

Discussion

90793.	(A): Chlorophyll contains one magnesium atom (R): Chlorophyll is useful to perform photosynthesis in plants
Answer» Both A & R are TRUE, R is the CORRECT explanation of A Both A & R are true, R is not correct explanation of A A is true, R is FALSE A is false, R is true Answer :B

Discussion

90794.	A chloroform solution of aniline is heated with KOH. Which of the following is right.
Answer» Chloroform HYDROLYSED to give formic acid Aniline REACTS with chloroform to give cyanides A secondary AMINE is obtained Foul smelling compound is obtained Solution :carbylamine `"REA"^(n)R-NC` test

Discussion

90795.	A chloro derivative (X) on treatment with Znand HCl gave a hydrocarbon with five carbon atoms in the molecule when (X) is dissolved in ether and treated with Na, the product 2,2,5,5-tetra methyl hexane is obtained. The compound (X) is
Answer» 3-chloro-2,2-dimethylpropane 1-chloropropane 1-chloro-2,2-dimethylpropane 2-chloro-2-methylbutane Answer :C

Discussion

90796.	A chloro compound (A) showed the following properties. It decolourised bromide water. It reacts with H_(2) in presence of catalyst. It gave a brick red precipitate with an ammonical Cu_(2)Cl_(2). When vaporized with 1.49g of (A) gave 448 ml of vapours at STP. on reaction with excess of hydrogen and nickel gave 'B'. calculate the molecular weight of 'B'.
Answer» ANSWER :`0044`

Discussion

90797.	A chloro compound (A) showed the followingproperties: (i) Decolorized bromine in "CCI"_4(ii) Absorbed hydrogen catalytically (iii) Gave a precipitate with amm. cuprous chloride (iv) When vaporized, 1.49 g of (A) gave 448 mL of vapour at STP. Identify (A).
Answer» SOLUTION :`ClCH_2C -=CH`

Discussion

90798.	(A) : Chlorine is gas, bromine is liquid and iodine is solid (R) : Intermolecular attraction forces increase upon increase in molecular masses .
Answer» Both (A) and (R ) are TRUE and (R ) is the correct explanation of (A) Both (A) and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is FALSE Both (A) and (R ) are false Answer :A

Discussion

90799.	(A) Chlorine dioxide is paramagnetic (R ) Chlorine dioxide molecule has odd number of electrons
Answer» Both (A) and (R ) are TRUE and (R ) is the correct explanation of (A) Both (A) and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is FALSE Both (A) and (R ) are false ANSWER :A

Discussion

90800.	(A) : Chlorine acts as a bleaching agent in the presence of moisture (R) : Chlorine forms hypochlorous acid in the presence of moisture.
Answer» Both (A) and (R ) are true and (R ) is the CORRECT EXPLANATION of (A) Both (A) and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is FALSE Both (A) and (R ) are false ANSWER :A

Discussion

Explore topic-wise InterviewSolutions in .

A colloid is formed by adding FeCl_3 in excess of hot water. What will happen if excess sodium chloride is added to this colloride ?

(A) Colloidal particles show Brownian Movement(R ) Brownian movement arises because of the impact of the molecules of the dispersion medium with the colloidal particles.

A colloid is formed by adding FeCl, in excess of hot water. What will happen if excess sodium chloride is added to this colloid ? The

A colloid is formed by adding FeCL_(3) in excess of hot water. What will happen if excess of sodium chloride is added to this colloid ?

A colloid always :

A cold, green flame can be made by passing CO_2 over warm:

A codonhas a sequence of A, and specific a particular B that is to be incorporated into C. what are A,B,C

A codon on the mRNA has :

A codon has a sequence of A and specifies a particular B that is to be incorporated into C what are ? A,B,C

(A) : CoCl_3 . 3NH_3 does not ionise in aqua solution. (R ): CoCl_3 . 3NH_3 is an example of aionic compounds.

(A) : [Co_(2)(OH)_(3)(NH_(3))_(6)]Cl_(3) is an example of polynuclear complex compound (R) : Compound in which the number of central metal atoms is more than one is called polynuclear compound

(A) : CO_(2) reacts with Grignard reagent followed by acid catalysed hydrolysis gives carboxylic acid . (R) : Alkyl halide reacts with Mg in the presence of ether gives Grignard reagent .

A CO_2 molecule contains:

A co -polymer ofvinyl chlorideand vinyledene chloride is called:

A co -polymer ofvinyl chlorideand vinylidene chloride is called:

A co -polymer ofvinyl chlorideand vinyacetate is called:

A co -polymer ofvinyl chlorideand vinyl acetate is called:

A co -polymer ofisobutylene and isoprene is called:

A co-polymer is one in which

Assertion:Co-ordination compounds are generally formed by transition metals. Reason :Transition metals generally have partly filled d-orbitals in n^(th) shell.

A co-ordination complex has the formula PtCl_(4).2KCl. Electrical conductance measurement indicate the presence of three ion in one formula unit. Treatment with AgNO_(3) produces no precipitate of AgCl. What is the co-ordination number of Pt in this complex ?

A closed vessel with rigid walls contains 1 mole of ._(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ._(92)^(238)U to ._(82)^(206)Pbthe ratio of the final pressure to the initial pressure of the system at 298K is

A closed vessel with rigid walls contains 1 mole of ""_(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ""_(92)^(238)U to ""_(82)^(206)Pb, the ratio of the final pressure to the initial pressure of the system at 298K is…..

A closed vessel with rigid walls contains 1 mol of ._(92)^(238)U and 1 mole of air at 298K. Considering complete decay of ._(92)^(238)U " to " ._(82)^(206)Pb, the ratio of the final pressure to the initial pressure of the system at 298 K is

A closed flask contains water in all its three states, solids, liquid and vapour at 0@C. In this situation the average KE of the water molecule will be:

A closed cylinder contains 40 g of SO_3 and 4 g of helium gas at 375 K. If the partial pressure of helium gas is 2.5 atm, then the volume of the container is (R = 0.082 L-atm K^-1 mol^-1)

A clock spring is heated to redness and then plunged into cold water. This treatment will cause it to become

A clock spirng is heated to a high temperature and then suddenly pluged into cold water . This treatment will cause the metal to becone :

A clear solution is heated in a china dish where upon a solid separates from the hot solution. It is due to the fact that

A clathrate is defined as:

A class of drugs useful to inhibit the pathogenic action of microbes are called.

(A): Cl - O bond length decreases from CIO^(-) to ClO_(4)^(-) (R): CI-O bond order increases from CIO^(-) to CIO_(4)^(-).

(A) cis-2-butene overset(HCO_3H)rarrI (B) trans-2-butene overset(HCO_3H)rarrII Correct statements are

A current of 2 ampere was passed through solution of CuSO_4 and AgNO_3 in series.0.635 g of copper was deposited .Then the weight of silver deposited will be:

A chocolate brown coloured compound with acetic acid and potassium ferrocyanide is obtained from a salt solution containing :

(A) Chromates and dichromates are not interconvertible in aqueous solution with charge in pH. (R) Chromates are orange in colour.

(A): Chlorophyll contains one magnesium atom (R): Chlorophyll is useful to perform photosynthesis in plants

A chloroform solution of aniline is heated with KOH. Which of the following is right.

A chloro derivative (X) on treatment with Znand HCl gave a hydrocarbon with five carbon atoms in the molecule when (X) is dissolved in ether and treated with Na, the product 2,2,5,5-tetra methyl hexane is obtained. The compound (X) is

A chloro compound (A) showed the followingproperties: (i) Decolorized bromine in "CCI"_4(ii) Absorbed hydrogen catalytically (iii) Gave a precipitate with amm. cuprous chloride (iv) When vaporized, 1.49 g of (A) gave 448 mL of vapour at STP. Identify (A).

(A) : Chlorine is gas, bromine is liquid and iodine is solid (R) : Intermolecular attraction forces increase upon increase in molecular masses .

(A) Chlorine dioxide is paramagnetic (R ) Chlorine dioxide molecule has odd number of electrons

(A) : Chlorine acts as a bleaching agent in the presence of moisture (R) : Chlorine forms hypochlorous acid in the presence of moisture.