94420 + Interview Questions in Chemistry in Class 12

1.	Depending upon concentration , phenol can be used both as an _______as well as a _______
Answer» ANSWER :ANTISEPTIC , DISINFECTANT

Discussion

2.	Deoxyribonucleic acid (DNA) consists of the following units:
Answer» Peptides Glucosides Nucleotides Deoxyribose Answer :C

Discussion

3.	Deoxyadenylic acid, deoxyguanylic acid, deoxythymidylic acid & deoxycytidylic acid are
Answer» Necleotides of DNA FATTY acids Necleosides of DNA Nucleotides of RNA Answer :A

Discussion

4.	Deoxyribonucleic acid (DNA) is a polymer of units called:
Answer» Sugars Ribose Amino acids Nucleosides Answer :D

Discussion

5.	Dental amalgam is composed of:
Answer» Hg+Ag + Cd+Au+Fe CU + Sn+Hg+Ag + Zn Cd + Cu + Ni+Au + Fe Cu + Sn+Au+Hg + CO Answer :B

Discussion

6.	Density order of alpha, beta, gamma forms in Sulphur
Answer» `alpha gt BETA gt gamma` `alpha LT beta lt gamma` `alpha gt gamma gt beta` `S_(gamma)gtS_(alpha)gtS_(beta)` Answer :A

Discussion

7.	Density order of alpha, beta , gamma forms in Sulphur
Answer» `ALPHA GT BETA gt gamma` `alpha lt beta lt gamma` `alpha gt gamma gt beta ` `S_(gamma) gt S_(alpha) gt S_(beta)` ANSWER :A

Discussion

8.	Density of water at room tempearture is 1.0g cm^(-3). How many molecules are there in one drop of water if its volume is 0.1 cm^(3)?
Answer» SOLUTION :Mass of one DROP `"vol".xxd=0.1xx1=0.1g` No. of moles `=(0.1)/(18)`: No. of MOLECUELS `=6.02xx10^(23)xx(0.1)/(18)`.

Discussion

9.	Density of solution prepared by dissolving 120 gm urea in 1000 gm water is 1.15 gm/mL then find out molarity of solution is …….
Answer» 0.50 M 1.78 M 1.02 M 2.05 M ANSWER :D

Discussion

10.	Density of solid is given by
Answer» `d=(zM)/(a^(3)N_(A)` `d=(a^(3)N_(A))/(zM)` `d=(ZA^(3))/(MN_(A))` `d=(zN_(A))/(a^(3)M)` Answer :A

Discussion

11.	Density of nitrogen gas prepared from air is slightly greater than that of nitrogen prepared by chemical reaction from a compound of nitrogen due to the presence of
Answer» argon carbon dioxide some `N_(3)` molecules analogous to `O_(3)` greater amount of `N_(2)` molecules derived from N-15 isotope Solution :Air contains about 1% inert gases, MAINLY Ar (At. Wt=40). The atomic wt. of `N_(2)` is 28.

Discussion

12.	Density of silver metal is 10.8 g c c^(-1), A 20 xx 10 cm thin iron foil is totally immersed in aqueous silver nitrate. Making it as cathode, electrolysis is done using a current strength of 1930 amp for a period of 100 sec. Calculate the thickness of silver metal electroplated on each face of iron foil.
Answer» Solution :Quantity of ELECTRICITY (Q) = it = `1930 xx 100 = 193000` coul. Amount of silver depsited using `193000 coul = (193000 xx 108)/(96500) = 216g` Amount of silvre DEPOSITED on each face of the iron foil = 108 g Volume of silver electroplated on each face of the iron foil = `w/d = (108)/(10.8) = 10 cc` The volume is given as, `v = (l + b) xx t, ` if (t) is the thickness and `(l xx b)` is AREA. thickness of silver electroplated = `("Volume")/("area") = 10/(20 xx 10) = 0.05 cm = 0.5 mm.`

Discussion

13.	Density of nitrogen gas prepared from air is slightly greater than that of nitrogen prepared by chemical reaction from a compound ofnitrogen because aerial nitrogen contains
Answer» `CO_2` Argon Some `N_2` MOLECULES analogous to `O_2` GREATER amount of `N_2` molecules DERIVED from `N_15` isotope Answer :B

Discussion

14.	Density of methane at 250^@ C and 6 atm pressure is ( R = 0.821 atm) :
Answer» 2.236 g/L 8 g/L 12 g/L 16 g/L Answer :A

Discussion

15.	Density of ionic substance is unchanged in Frenkel defect, but the conductivity of ionic crystalline solid increases. Comment.
Answer» Solution :In Frenkel defect the cations missing at lattice points APPEAR at interstitial SITES. The total number of ions is conserved and hence density is constant. HOWEVER conductivity increases because of the lattice VACANCY and interstitial OCCUPANCY of the ions in the lattice of the crystal.

Discussion

16.	Density of ideal gas of molecular mass 32 u at 1.2 atm pressure and 327 °C is
Answer» `0.072 GL^- 1` `0.78 gL^- 1` `7.8 gL^- 1` `7.2 gL^- 1` ANSWER :4

Discussion

17.	Density of ether is
Answer» HIGHER than water equal to water lower than water can't be predicted Answer :C

Discussion

18.	Density of ammonia is 0.77 g/litre at NTP. Its vapour density is :
Answer» 8.65 86.5 4.33 43.3 Answer :A

Discussion

19.	Density of carbon monoxide is maximum at
Answer» 2 atm and 600K 0.5 atm and 273K 6 atm and 1092K 4 amt and 500K Solution :DENSITY of a GAS, `d = ( p M )/( RT) ` or `d alpha( p )/( T)` By using this RELATION, density is MAXIMUM at 4 atm and 500K.

Discussion

20.	Density of a unit cell is given by
Answer» `d=(N_(A))/(ZMA^(3))` `d=(a^(3)N_(A))/(ZM)` `d=(a^(3)M)/(ZN_(A))` `d=(ZM)/(a^(3)N_(A))` ANSWER :D

Discussion

21.	Density of a crystal is given by :
Answer» `(a^(3)xxM)/(zxxN_(0))` `(N_(0)xxM)/(zxxa^(3))` `(zxxM)/(a^(3)xxN_(0))` `(a^(3)XXN^(0))/(zxxM)` ANSWER :C

Discussion

22.	Density of 2.05 M solution of acetic acid in water is 1.02g//mL. The molality of same solutionis:
Answer» 1.14 m 3.28 m 2.28 m 0.44 m Solution :2.05 M solution of acetic acid means that `(2.05xx60=123 G)` of acid is present in 1000 mL of solutiion Mass of solution=`Vxxd` =`(1000mL) XX (1.02 g mol^(-1))` =1020 g `"Mass os SOLVENT"= 1020-123=897 g.` `"Molality (m)"=((2.05 mol))/((0.897 KG))` `=2.28 mol kg^(-1)=2.28 m`

Discussion

23.	Density of a 2.05 M solution of acetic acid in water is 1.02 g/ml. The molarity of the solution is :
Answer» 3.28 mol `kg^(-1)` 2.28 mol `kg^(-1)` 0.44 mol `kg^(-1)` 2.14 mol `kg^(-1)` SOLUTION :MASS of 1 L solution of 2.05 M ACETIC ACID `=1.02xx1000=1020` G Mass of solute in solution `=2.05xx60=123g` Mass of solvent in solution `=1020-123=897` g Molality `=(2.05xx1000)/(897)=2.28 "mol kg"^(-1)`.

Discussion

24.	Density of 2M NaCI solution is 1.25 g/cc.The molality of the solution is :
Answer» 2.79 molal 0.279 molal 1.279 molal 3,85 molal Solution :`"Mass of 3 M NaCI solution" = "density" x "volume" =(1.25g/ccxx1000cc)=1250g ` MOLAR mass of NaCI =58.5 G/mol Mass of 3 moles of NaCI=`(58.5 g mol)XX(3 mol)=1.074 kg` `"Molality of solution"=("No.of moles of NaCI")/("Mass of solvent in kg")` `=((3mol))/((1.074 kg))=2.79 mol kg^(-1)=2.79 molal`

Discussion

25.	Density , malleability and ductility in coinage metals increase in the order :
Answer» CU , AG , AU Au, Ag, Cu Ag, Au ,Cu Ag ,Cu , Au ANSWER :A

Discussion

26.	Densities of transition metals are:
Answer» Low Very low High Very high Answer :D

Discussion

27.	Denatured spirit is mainly used as a
Answer» good fuel DRUG solvent in PREPARING varnishes material in the PREPARATION of oil ANSWER :C

Discussion

28.	Densest transition element is :
Answer» Fe Sc Os Mn Answer :C

Discussion

29.	Denatured spirit in mainly used as a
Answer» Goodfuel Drug Solvent in PREPARING varnishes Material in the PREPARATION of oil Answer :C

Discussion

30.	Denatured spirit is mainly used as a :
Answer» GOOD fuel Drug Solvent in PREPARING varnishes Material in the PREPARATION of oil Answer :C

Discussion

31.	Denatured alcohol is
Answer» ethanol + METHANOL rectified spirit + methanol + naphthalene undistilled ethanol rectified spirit Solution :DENATURED alcohol or methylated spirit `RIGHTARROW` mixture of `90%` ethanol, `9%` methanol and `1%` other poisonous substances like pyridine and acetone or petroleum oil. Rectified spirit `rightarrow` 95% alcohol + 5% water.

Discussion

32.	Denatured alcohol is :
Answer» Recified spirit Undistilled ETHANOL Rectified spirit `+10-15%`methanol + NAPHTHA + pyridine `50%` ethanol `+50%` methanol Answer :C

Discussion

33.	Denaturation of proteins leads to loss of its biological activity by
Answer» FORMATION of amino ACIDS LOSS of PRIMARY structure loss of both primary and secondary structure loss of both secondary and TERTIARY structure Answer :D

Discussion

34.	Denaturation of protein leads to loss of its biological activity by
Answer» FORMATION of amino acids LOSS of primary STRUCTURE Loss of both primary & quaternary structures Loss of both SECONDARY and tertiary structures ANSWER :D

Discussion

35.	Denaturation of protein
Answer» DISRUPTS the `1 ^(@)` and `2^(@)` structure of proteins disrupts the 2° and 3° structure of proteins disrupts 1 °,2°,3° structure of proteins is REVERSIBLE process Answer :B

Discussion

36.	Denaturation of alcohol is the
Answer» mixing of `CuSO_(4)` (a FOUL SMELLING solid) and pyridine (to GIVE the colour) to make the commercial alcohol unfit for drinking mixing of `CuSO_(4)` (to give the colour) and pyridine (a foul smelling solid) to make the commercial alcohol unfit for drinking Mixing of `Cu(OAc)_(2)` and AMMONIA to make the commercial alcohol unfit for drinking. Mixing of `Cu(OAc)_(2)` and pyridineto make the commercial alcohol unfit for drinking. Solution :The commercial alcohol is made unfit for drinking by mixing in it some copper sulphate (to give it colour) and pyridine (a foul smelling liquid). lt is known as denaturation of alcohol.

Discussion

37.	Denaturation of ethyl alcohol is made by adding
Answer» methanol only Phyride only methanol and pyridine ZINC SULPHATE ANSWER :C

Discussion

38.	Denaturation involves converstion of ...............proteins to ...........proteins.
Answer» SOLUTION :globuular, FIBROUS

Discussion

39.	Demineraisled H_(2)O is obtained when
Answer» WATER is passed through `R-SO_(3)`H resin Water is passed through `R-OVERSET(+)NH_(3)Ooverset(Theta)H` resin Water is passed through both `RSO_(3)H` resin and `R" "overset(o+)NH_(3)OoversetTheta(H)` resin We can't get demineralised `H_(2)O` artificially by resins Answer :C

Discussion

40.	Denaturation does not involve
Answer» BREAKING up of H-bonding in proteins the loss of BIOLOGICAL action of enzyme he loss of secondary STRUCTURE. loss of PRIMARY structure of proteins Solution :loss of primary structure of proteins

Discussion

41.	DeltaUis equal to
Answer» ISOCHORIC work isoboric work adiabatic work isothermal work Answer :C

Discussion

42.	DeltaU is equal to:
Answer» ISOBARIC work Adiabatic work Isothermal work Isochoric word Answer :B

Discussion

43.	DeltaU^(@) for combustion of methane is -X kJ mol^(-1). The value of DeltaH^(@) is
Answer» `=DeltaU^(@)` `gtDeltaU^(@)` `LT DeltaU^(@)` `=0` Solution :`CH_(4)(g)+2O_(2)(g) to CO_(2)(g)+2H_(2)O(l)` `Deltan_(g)=(n_(p)-n_(R))=1-3=-2` `DeltaH^(@)=DeltaU^(@)+Deltan_(g)RT=-X-2RT` Hence, `DeltaH^(@) lt Delta U^(@)`

Discussion

44.	DeltaU equal to
Answer» Isobaric WORK ADIABATIC work Isothermal work Isochoric work Solution :For Adiabatic PROCESS, Q = 0 Now, `DeltaU=Q+Wimplies DeltaU=W`

Discussion

45.	Delta_tG° for the following reactionI_2(s) + H_2S(g) rarr 2HI(g) + S(s) at 298 K is, given that Delta_IG°HI(g) = 1.8 kJ mol^-1. Delta_IG°H_2S(g) = 33.8 kJ mol^-1.
Answer» 30200 KJ 30.2 kJ -30200J -302 J ANSWER :C

Discussion

46.	Delta_(r)H^(Theta) of Cyclohexene (l) and benzene at 25^(@)C is -156 and + 46kJ mol^(-1), respectively. Delta_("hydrogenation")H^(Theta) of cyclohexene (l) at 25^(@)C is -119 kJ mol^(-1) Resonance energy of benzene is found to be -38x kJ mol^(-1). Find the value of x
Answer» Solution :`+H_(2(g))rarrDeltaH^(THETA)=-119 kJ mol^(-1)` This SHOWS that the generation of ONE (C=C) bond in cyclohexene requires 119 kJ `mol^(-1)` of enthalpy. To calculate RE resonance energy. `DeltaH_(1)^(Theta)=DeltaH_(2)^(Theta)=DeltaH_(3)^(Theta)=119 kJ mol^(-1), DeltaH_(4)^(Theta)=RE` `DeltaH_(5)^(Theta)=Delta_(f)H^(Theta)"(benzene)"-Delta_(f)H^(Theta)"(Cyclohexene)"` `=46-(-156)=205kJ mol^(-1)""therefore" From Hess' LAW"` `DeltaH_(4)^(Theta)=DeltaH_(5)^(Theta)-(DeltaH_(1)^(Theta)+DeltaH_(2)^(Theta)+DeltaH_(3)^(Theta))` `=205-3xx119=-152 kJ mol^(-1)""therefore-38x=-152` x=4.

Discussion

47.	Delta_(r) H of which of the following reactions is zero ?
Answer» `H_(2) (G) + 2 H^(+) (g) + 2E^(-)` `2 H(g) + AQ to 2 H^(+) aq + 2e^(-)` `2 H (g) to 2 H^(+) (g) + 2e^(-)` `H_(2) (g) + aq to 2 H^(+) (aq) + 2e^(-)` Answer :D

Discussion

48.	DeltaH_("vap")=30kJ//"mol"andDeltaS_("vap")=75J"mol"^(-1)K^(-1). Find the temperature of the vapour at 1 atm.
Answer» 400 K 350 K 298 K 250 K Solution :`T=(DELTAH)/(DELTAS)`

Discussion

49.	Deltan, the change in the number of moles for the reactin, C_(12)H_(22)O_(11(s))+12O_(2(g))hArr12CO_(2(g))+11H_(2)O_((1))at 25^(@)C is
Answer» 0 2 4 `-1` Solution :`C_(12)H_(22)O_(11(s))+12O_(2(g))to12CO_(2(g))+11H_(2)O` `Deltan=12-12=0`

Discussion

50.	DeltaH_(f)^(@) " for "H_(2)O_(2) and H_(2)O are -188 kJ/mole and -286 kJ/mole. What will be the enthalpy change of the reaction 2H_(2)O_(2)(l)rarr2H_(2)O(l)+O_(2)(g)
Answer» `-196` kJ/mole `146 kJ//"mole"` `-494 kJ//"mole"` `-98 kJ//"mole"` Solution :`H_(2)+O_(2)rarrH_(2)O_(2) ""DeltaH_(f)^(@)=-188 kJ//"mole...(i)"` `H_(2)+(1)/(2)O_(2)rarrH_(2)O_(2)" " DeltaH_(f)^(@)=-286 kJ//"mole...(II)"` eq. (i) - eq. (ii) `xx2` gives the required result.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Depending upon concentration , phenol can be used both as an _______as well as a _______

Deoxyribonucleic acid (DNA) consists of the following units:

Deoxyadenylic acid, deoxyguanylic acid, deoxythymidylic acid & deoxycytidylic acid are

Deoxyribonucleic acid (DNA) is a polymer of units called:

Dental amalgam is composed of:

Density order of alpha, beta, gamma forms in Sulphur

Density order of alpha, beta , gamma forms in Sulphur

Density of water at room tempearture is 1.0g cm^(-3). How many molecules are there in one drop of water if its volume is 0.1 cm^(3)?

Density of solution prepared by dissolving 120 gm urea in 1000 gm water is 1.15 gm/mL then find out molarity of solution is …….

Density of solid is given by

Density of nitrogen gas prepared from air is slightly greater than that of nitrogen prepared by chemical reaction from a compound of nitrogen due to the presence of

Density of nitrogen gas prepared from air is slightly greater than that of nitrogen prepared by chemical reaction from a compound ofnitrogen because aerial nitrogen contains

Density of methane at 250^@ C and 6 atm pressure is ( R = 0.821 atm) :

Density of ionic substance is unchanged in Frenkel defect, but the conductivity of ionic crystalline solid increases. Comment.

Density of ideal gas of molecular mass 32 u at 1.2 atm pressure and 327 °C is

Density of ether is

Density of ammonia is 0.77 g/litre at NTP. Its vapour density is :

Density of carbon monoxide is maximum at

Density of a unit cell is given by

Density of a crystal is given by :

Density of 2.05 M solution of acetic acid in water is 1.02g//mL. The molality of same solutionis:

Density of a 2.05 M solution of acetic acid in water is 1.02 g/ml. The molarity of the solution is :

Density of 2M NaCI solution is 1.25 g/cc.The molality of the solution is :

Density , malleability and ductility in coinage metals increase in the order :

Densities of transition metals are:

Denatured spirit is mainly used as a

Densest transition element is :

Denatured spirit in mainly used as a

Denatured spirit is mainly used as a :

Denatured alcohol is

Denatured alcohol is :

Denaturation of proteins leads to loss of its biological activity by

Denaturation of protein leads to loss of its biological activity by

Denaturation of protein

Denaturation of alcohol is the

Denaturation of ethyl alcohol is made by adding

Denaturation involves converstion of ...............proteins to ...........proteins.

Demineraisled H_(2)O is obtained when

Denaturation does not involve

DeltaUis equal to

DeltaU is equal to:

DeltaU^(@) for combustion of methane is -X kJ mol^(-1). The value of DeltaH^(@) is

DeltaU equal to

Delta_tG° for the following reactionI_2(s) + H_2S(g) rarr 2HI(g) + S(s) at 298 K is, given that Delta_IG°HI(g) = 1.8 kJ mol^-1. Delta_IG°H_2S(g) = 33.8 kJ mol^-1.

Delta_(r)H^(Theta) of Cyclohexene (l) and benzene at 25^(@)C is -156 and + 46kJ mol^(-1), respectively. Delta_("hydrogenation")H^(Theta) of cyclohexene (l) at 25^(@)C is -119 kJ mol^(-1) Resonance energy of benzene is found to be -38x kJ mol^(-1). Find the value of x

Delta_(r) H of which of the following reactions is zero ?

DeltaH_("vap")=30kJ//"mol"andDeltaS_("vap")=75J"mol"^(-1)K^(-1). Find the temperature of the vapour at 1 atm.

Deltan, the change in the number of moles for the reactin, C_(12)H_(22)O_(11(s))+12O_(2(g))hArr12CO_(2(g))+11H_(2)O_((1))at 25^(@)C is

DeltaH_(f)^(@) " for "H_(2)O_(2) and H_(2)O are -188 kJ/mole and -286 kJ/mole. What will be the enthalpy change of the reaction 2H_(2)O_(2)(l)rarr2H_(2)O(l)+O_(2)(g)

Depending upon concentration , phenol can be used both as an _as well as a _