94420 + Interview Questions in Chemistry in Class 12

1.	In an aquose solution of D-Glucose the percentage of alpha and beta anomers at equilibrium condition are respectively
Answer» 80 and 20 20 and 80 36 and 64 64 and ANSWER :C

Discussion

2.	In an aqueous solution the ionisation constants for carbonic acid are K_(1)=4.2xx10^(-7)andK_(2) =4.8xx10^(-11). Select the correct statement for a saturated 0.034 M solution of the carbonic acid.
Answer» The concentration of `CO_(3)^(2-)` is 0.034 M The concentration of `CO_(3)^(2-)` is GREATER than that of `HCO_(3)^(-)` The concentration of `H^(+)andHCO_(3)^(-)` are approximately equal The concentration of `H^(+)` is double that of `CO_(3)^(2-)` Solution :`K_(1)gtgtK_(2)`, i.e., SECOND dissociation is practically negligible

Discussion

3.	In an aqueous solution of urea, mole fraction of urea is 0.4. Then w/w% of urea is:
Answer» 0.155 0.31 0.345 0.69 Solution :Mole FRACTION of urea =0.4 0.4 MOLES of urea +0.6 moles of `H_(2)O` `%(w//w)=(0.4xx60)/((0.4xx60)+(0.6xx18))=(24)/(24+10.8)XX100` `=(24)/(34.8)xx100=69%`

Discussion

4.	In an aqueous solution, hydrogen (H_(2)) will not reduce:
Answer» `Fe^(3+)` `Cu^(2+)` `ZN^(2+)` `AG^(+)` Solution :Only `Zn` and `Fe` are above `H`, ALSO `Fe^(3+)` can be REDUCED to `Fe^(2+)` by `H`.

Discussion

5.	In an aqueous solution, how does specific conductivity of electrolytes change with addition of water?
Answer» Solution : SPECIFIC conductivity decreases because the number of IONS PER unit VOLUME decreases.

Discussion

6.	In an aqueous solution containing Cu^(2+), Ag^(+), Sn^(2+) and Hg_(2)^(2+) ions, the concentration of each ion is 1 (M). Electrolysis of the solution is carried out in presence of inert electrodes. Given: E_(Hg_(2)^(2+)\|Hg)^(@)=+0.79V and E_(Sn^(2+)\|Sn)^(@)=-0.14V. If the voltage applied on the electrodes is gradually increased, then the metal that will deposit first and that at the end of the process at the cathode, respectively, are -
Answer» SN, Ag Cu, Hg Cu, Sn Ag, Sn Answer :D

Discussion

7.	In an aqueous solution how does specific conductivity of electrolytes change with addition of water?
Answer» SOLUTION :Conductivity decreases because NUMBER of IONS per unit VOLUME decreases.

Discussion

8.	In an aqueous solution, how does specific conductivity of electrolytes change with addition of water ?
Answer» Solution :* SPECIFIC CONDUCTIVITY of solution decreases with DILUTION of solution. * On addition of water to the electrolytic solution, i.e., on dilution the interionic distance between ions get increases. So, number of ions in specific volume of solution get decreases. and hence, specific conductivity get decreases on dilution.

Discussion

9.	In an aqueous of volume500 ml when the reaction, 2Ag^(+) + Cu rarr Cu^(2+) + 2Ag, reaches equilibrium, the concentration of Cu^(2+) ions is x molar: To this solution 500ml of water is added. At the new equilibrium the concentration of Cu^(2+) ions would be
Answer» 2X molar between XAND 2x molar less than `(1)/(2) X `molar between 0.005x molar and 0.5x molar Answer :C,D

Discussion

10.	In an analytical determination of aresenic , a solution containing aresenious acid, (H_(3)AsO_(3)). KI and a small amount of starch is electrolysed. The electrolysis produes free I_(2) from I^(-) ion and the I_(2) immediately oxidises the arsenious acid to hydrogen arsenate ion, (HAsO_(4)^(2-)). I_(2(aq.))+H_(3)AsO_(3(aq.))+H_(2)O_((l))rarr2I_((aq.))^(-)+HAsO_(4(aq.))^(2-)+4H_((aq.))^(+) When the oxidation of arsenic is complete, the free iodine combines with thestarch to give a deep blue colour.If during a particular run, it takes 65.3 s for a current of 10.5 mA to give an end point (indicated by the blue colour), how many grams of arsenic and H_(3)AsO_(3) are present in the solution? ("At. wt. of "As = 75)
Answer» ANSWER :As `= 2.66 XX 10^(-4)g`, `H_(3)AsO_(3) = 5.0 xx 10^(-4)g ;`

Discussion

11.	In an antiflourite structure, cations occupy
Answer» OCTAHEDRAL VOIDS centre of cube tetrahedral voids CORNERS of cube Answer :C

Discussion

12.	In an answer paper a student wrote as "carborundum crystals are very soft." What is your opinion?
Answer» SOLUTION :CARBORUNDUM CRYSTALS are very HARD.

Discussion

13.	In an answer paper a student wrote as "carborundum crystals are very soft." Do you agree with this?
Answer» ANSWER :no

Discussion

14.	In an answer paper a student wrote as "carborundum crystals are very soft." In which crystal type carborundum is included?
Answer» SOLUTION :Covaient CRYSTAL.

Discussion

15.	In an amino acid, the carboxyl group ionises at pK_(a_1)=2.34 and ammonium ion at pK_(a_2)=9.60 . The isoelectric point of the amino acid is at pH
Answer» 5.97 2.34 `9.60` `6.97` Solution :ISOELECTRIC POINT (pH) `=(pK_(a_1) + pK_(a_2))/2 =(2.34+9.60)/2`=5.97

Discussion

16.	In an amino - acid , the carboxyl group ionises at pKa_(1) = 2.34 and the ammonium ion at pKa_(2) = 9.60 . The isoelectric point of the amino acid is at pH ………………..
Answer» 5.97 2.34 9.6 6.97 Answer :A

Discussion

17.	In an adsorption expetiment, a graph between log (x/m) varuse log P was found to be linear with a slope of 45^(@). The intercept on the log (x/m) axis was found to be 0.3010. Calculate the amount of the gas adsorbed per gram of charcoal under a pressure of 0.5 atmosphere.
Answer» Solution :According to Freundlich equation, `x/m =k P^(1//) or log ""(x)/(m)=log k+1/n log P` `THEREFORE` Plot of `x/m` varsus log P is linear with SLOPE `=1/n` and INTERCEPT `=log k.` Thus, `1/n = TNA theta = TAN 45^(@)=1 or n=1` `log k =0.3010 or k= "Antilig" 0.3010=2` At `P =0.5 atm, x/m =k P^(1//n)=2xx(0.5)^(1)=1.0`

Discussion

18.	In an adsorption experiment a graph between log x/m vs. log p is found to be linear with a slope of 45^(@). The intercept on the log x/m axis was found to be 0.3010. What is x/m If presure is 0.6 bar (tan 45^(@) = 1)
Answer» 0.6 1.2 2.4 0.3 Answer :B

Discussion

19.	In an alkalinemedium acetaldehyde undergoes :
Answer» Benzoin condensation Aldol condensation Polymerisation Cannizzaro.s reaction ANSWER :B

Discussion

20.	In an adsorption experiment, a graph of log(x/m) versus log P was found to be linear with a slope of 45°, and the the intercept of of 0.3010. The amount of gas adsorbed per gram charcoal under a pressure of 0.8 bar is
Answer» 1.2 1.4 1.6 1.8 Answer :C

Discussion

21.	In an Adsorption experiment a graph between log x/m versus log P was found to be linear with a slope of 45^(@) the intercept of the log x/m was found to be 0.3010. Calculate the amount of gas adsorbed per gram of charcoal under a pressure of 0.6 bar.
Answer» SOLUTION :`1.2`

Discussion

22.	In an adsorption experiment a graph between log x/m vs. log p is found to be linear with a slope of 45^@ . The intercept on the log x/m axis was found to be 0.3010. What is x/m if pressure is 0.6 bar
Answer» 0.6 1.2 2.4 0.3 Answer :B

Discussion

23.	In an adiabatic process:
Answer» The system EXCHANGES HEAT with surrounding Pressure is maintained constant There is perfect heat insulation The GAS is isothermally expanded Answer :C

Discussion

24.	In an adiabatic expansion of an ideal gas.
Answer» `DELTA T = 0` W = 0 q = 0 `Delta U = 0`. Answer :C

Discussion

25.	In an acidic medium ………………….. behaves as the strongest base (nitrobenzen. Aniline, phenol),
Answer» ANSWER :ANILINE

Discussion

26.	In an acidified solution of K_2Cr_2O_7, H_2O_2 is added. Then
Answer» solution TURNS green due to formation of `Cr_2O_3` solution turns yellow due to formation of `K_2CrO_4` a blue coloured compound `CrO(O_2)_(2)` is FORMED solution gives green precipitate of `Cr(OH)_(3)` Answer :C

Discussion

27.	In Amylpectin the linkage absent is
Answer» `C_1 & C_4` `C_1 & C_6` `C_1 & C_2` Both `C_1 & C_6` and `C_1 &C_4` ANSWER :C

Discussion

28.	In amylopectin glycosidic long chain and branching occurs in between
Answer» C-1 of ONE `ALPHA`-D-glucopyranos`to`C-4 of ANOTHER `alpha`-D-GLUCOPYRANOSE and BRANCHING at C-1 of one glucopyranose C-6 of another glucopyranose Answer :A

Discussion

29.	In amylopectin glycosidic branching present in between
Answer» 1-4 `ALPHA`-D-glucopyranose 1-4-`BETA`-D-glucopyranose 1-6-`alpha`-D-glucopyranose 1-6 `beta`-D-glucopyranose Answer :C

Discussion

30.	In amixure of NaOH and NaCl 50% sodium is present. Calculate mass % of NaOH in the solution.
Answer» `95.2%` 0.5875 0.1567 0.227 Solution :In 100gm MIXTURE contain `W_(Na)=50GM` `n_(NAOH)=a, n_(NaCl)=b` 40a+58.5b=100 . . . .(i) `axx23+bxx23=50gm` `a+b=(50)/(23)` . . . .(ii) `40a+40b=(50xx40)/(23)` 40a+58.5b=100 `18.5b=100-(200)/(23)` `b=(100-86.9)/(18.5)=0.7`. `a=(50)/(23)-0.7=2.17-0.7` In 100 gm mixture `rArr W_(NaOH)=58.8rArr58.8%` APPROX.

Discussion

31.	In aluminothermic process aluminium acts as :
Answer» OXIDISING AGENT REDUCING agent flux None of these ANSWER :B

Discussion

32.	In aluminium extraction by the Baeyer's process, alumina is extracted from bauxite by sodium hydroxide at high temperatures and pressures. Al_(2)O_(3(s))+2OH_((aq))^(-) to 2AlO_(2(aq))^(-)+H_(2)O_(l) Solid impurities such as Fe_(2)O_(3) and SiO_(2) are removed and then Al(OH)_(4)^(-) is reprecipitated. In the industrial world
Answer» carbon dioxide is ADDED to precipitate the alumina temperature and pressure are dropped and the supersaturated SOLUTION seeded both (a) and (B) are practised the WATER is evaporated Solution :Both (a) and (b) are practised.

Discussion

33.	In aluminothermic process, Al is used as....
Answer» reducing AGENT OXIDISING agent CATALYST electrolyte ANSWER :A

Discussion

34.	In alumino-thermy, aluminium is heated with :
Answer» CALCIUM oxide Chromium oxide Magnesium oxide Sodium oxide Answer :B

Discussion

35.	In aluminium oxide, the oxide ions are arranged in hexagonal close packed (hcp) arrangement and the aluminium occupy 2//3 of octahedral voids. What is the formula of oxide ?
Answer» Solution :Number of octahedral sites corresponding to each atom in hcp=1 Number of OXYGEN (O) atoms = 1 It is GIVEN that `2//3` of the octahedral sites are OCCUPIED by aluminium ions. Hence, for each oxide ion, there will be `2//3` aluminium ions. so, number of AL atoms = `2//3` Hence, the formula of the oxide = `Al_(2//3) O_1` or `Al_2O_3`

Discussion

36.	In Alum: K_(2)SO_(4), Al_(2)(SO_(4))_(3). 24 H_(2)O Which metal can replace Al
Answer» Cr Mn In SC Solution :`K_(2)SO_(4), Cr_(2)(SO_(4))_(3)24H_(2)O` CHROME alum can FORM.

Discussion

37.	In aluminates, the coordination number of Al is
Answer» `O_(2)` `CO_(2)` HELIUM All of these Solution :In ARTIFICIAL repiration a mixture of `O_(2)` with `CO_(2)` or helium is used. Helium is used as it is less soluble in blood.

Discussion

38.	In aluminates coordination number of Al is :
Answer» 4 6 3 1 Answer :B

Discussion

39.	In alpha-helix structure of protein, each turn has nearly ………………….. number of amino acids.
Answer» 3.6 5 4 2.7 Answer :A

Discussion

40.	In alpha- helix structure intramolecular hydrogen bonding takes place between
Answer» NH- group of one UNIT and gtCO group of ANOTHER DIFFERENT unit NH- group of one unit and gtCO group of same part of same unit No HYDROGEN bonding between-NH- group and gtCO group Answer :B

Discussion

41.	In almost all Indian metropolitan cities like Delhi, the major atmospheric pollutants is/are
Answer» SUSPENDED PARTICULATE MATTER (SPM) Oxides of nitrogen Carbon DIOXIDE and carbon monoxide Oxides of sulphur Answer :A

Discussion

42.	Inalpha -helix , structure, polypepetide chains are folded in a
Answer» RIGHT HAND SIDE LEFT hand side both way none of these. ANSWER :A

Discussion

43.	In allylic alcohol - OH group is attached to
Answer» SP - hybridised CARBON ATOM `sp^2` - hybridised carbon atom `sp^3` - hybridised carbon atom `sp^3`-d-hybridised carbon atom Answer :C

Discussion

44.	In all expected compounds each central atom only uses its s and p-orbitals in hybridization. The relationship between bond angle 'theta' and decimal fraction of s and p character present in the equivalent orbitals is given by : costheta=(S)/(S-1)=(P-1)/(P), S=decimal fraction of s-character in the equivalent hybrid orbitaland P=decimal fraction of p-character in the equivalent hybrid orbital. . Q.The incorrect statement is :
Answer» The ratio in % p-character to % s-character is less than four, for the bond pair of CENTRAL atom of compound S Central atom USES three hybrid orbitals to form COMPOUNDS R Central atom uses four hybrid orbitals to form compounds S There are three compounds present between point C to E, according to % s-character in bond pair of central atom. Answer :D

Discussion

45.	In all green leaves and vegetables which of the following vitamin is avialable ?
Answer» VITAMIN A Vitamin D Vitamin K Vitamin `B_(12)` ANSWER :C

Discussion

46.	In all expected compounds each central atom only uses its s and p-orbitals in hybridization. The relationship between bond angle 'theta' and decimal fraction of s and p character present in the equivalent orbitals is given by : costheta=(S)/(S-1)=(P-1)/(P), S=decimal fraction of s-character in the equivalent hybrid orbitaland P=decimal fraction of p-character in the equivalent hybrid orbital. . Q. If the value n is 2 for compound T, then number of lone pair present at central atom of compound T will be :
Answer» `0` `1` `2` `3` SOLUTION :

Discussion

47.	In all expected compounds each central atom only uses its s and p-orbitals in hybridization. The relationship between bond angle 'theta' and decimal fraction of s and p character present in the equivalent orbitals is given by : costheta=(S)/(S-1)=(P-1)/(P), S=decimal fraction of s-character in the equivalent hybrid orbitaland P=decimal fraction of p-character in the equivalent hybrid orbital. . Q. The correct order of % p-character in bond pairs of central atoms in the following compounds is :
Answer» `PgtTgtSgtQgtR` `SgtRgtTgtPgtQ` `PgtQgtSgtRgtT` `PgtQgtSgtTgtR` ANSWER :D

Discussion

48.	In alkyl nitrites the oxygen of -O-N=O group is linked with carbon. An alkyl nitrite is :
Answer» An ester A NITRO compound An amide Anitrile Answer :A

Discussion

49.	In alkyl cyanide alkyl group attached with
Answer» C of CN GROUP N of CN group Either C or N of CN group Both C and N of CN group Answer :A

Discussion

50.	In alkanline medium ClO_(2) oxidises H_(2)O_(2) to O_(2) and itself gets reduced to Cl^(-). How many moles of H_(2)O_(2) are oxidised by 1 mol of ClO_(2)?
Answer» `1.0` `1.5` `2.5` `3.5` Solution :`(({:(2ClO_(2)+2OH^(-)to2Cl^(-)+H_(2)O+5[O]),(H_(2)O_(2)+[O]toH_(2)O+O_(2)xx5):})/(5H_(2)O_(2)+2ClO_(2)+2OH^(-)to6H_(2)O+2Cl^(-)+5O_(2)))/` THUS, ONE mole of `ClO_(2)` oxidises 5/2 or 2.5 moles of `H_(2)O_(2)`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In an aquose solution of D-Glucose the percentage of alpha and beta anomers at equilibrium condition are respectively

In an aqueous solution the ionisation constants for carbonic acid are K_(1)=4.2xx10^(-7)andK_(2) =4.8xx10^(-11). Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

In an aqueous solution of urea, mole fraction of urea is 0.4. Then w/w% of urea is:

In an aqueous solution, hydrogen (H_(2)) will not reduce:

In an aqueous solution, how does specific conductivity of electrolytes change with addition of water?

In an aqueous solution how does specific conductivity of electrolytes change with addition of water?

In an aqueous solution, how does specific conductivity of electrolytes change with addition of water ?

In an aqueous of volume500 ml when the reaction, 2Ag^(+) + Cu rarr Cu^(2+) + 2Ag, reaches equilibrium, the concentration of Cu^(2+) ions is x molar: To this solution 500ml of water is added. At the new equilibrium the concentration of Cu^(2+) ions would be

In an antiflourite structure, cations occupy

In an answer paper a student wrote as "carborundum crystals are very soft." What is your opinion?

In an answer paper a student wrote as "carborundum crystals are very soft." Do you agree with this?

In an answer paper a student wrote as "carborundum crystals are very soft." In which crystal type carborundum is included?

In an amino acid, the carboxyl group ionises at pK_(a_1)=2.34 and ammonium ion at pK_(a_2)=9.60 . The isoelectric point of the amino acid is at pH

In an amino - acid , the carboxyl group ionises at pKa_(1) = 2.34 and the ammonium ion at pKa_(2) = 9.60 . The isoelectric point of the amino acid is at pH ………………..

In an adsorption expetiment, a graph between log (x/m) varuse log P was found to be linear with a slope of 45^(@). The intercept on the log (x/m) axis was found to be 0.3010. Calculate the amount of the gas adsorbed per gram of charcoal under a pressure of 0.5 atmosphere.

In an adsorption experiment a graph between log x/m vs. log p is found to be linear with a slope of 45^(@). The intercept on the log x/m axis was found to be 0.3010. What is x/m If presure is 0.6 bar (tan 45^(@) = 1)

In an alkalinemedium acetaldehyde undergoes :

In an adsorption experiment, a graph of log(x/m) versus log P was found to be linear with a slope of 45°, and the the intercept of of 0.3010. The amount of gas adsorbed per gram charcoal under a pressure of 0.8 bar is

In an Adsorption experiment a graph between log x/m versus log P was found to be linear with a slope of 45^(@) the intercept of the log x/m was found to be 0.3010. Calculate the amount of gas adsorbed per gram of charcoal under a pressure of 0.6 bar.

In an adsorption experiment a graph between log x/m vs. log p is found to be linear with a slope of 45^@ . The intercept on the log x/m axis was found to be 0.3010. What is x/m if pressure is 0.6 bar

In an adiabatic process:

In an adiabatic expansion of an ideal gas.

In an acidic medium ………………….. behaves as the strongest base (nitrobenzen. Aniline, phenol),

In an acidified solution of K_2Cr_2O_7, H_2O_2 is added. Then

In Amylpectin the linkage absent is

In amylopectin glycosidic long chain and branching occurs in between

In amylopectin glycosidic branching present in between

In amixure of NaOH and NaCl 50% sodium is present. Calculate mass % of NaOH in the solution.

In aluminothermic process aluminium acts as :

In aluminothermic process, Al is used as....

In alumino-thermy, aluminium is heated with :

In aluminium oxide, the oxide ions are arranged in hexagonal close packed (hcp) arrangement and the aluminium occupy 2//3 of octahedral voids. What is the formula of oxide ?

In Alum: K_(2)SO_(4), Al_(2)(SO_(4))_(3). 24 H_(2)O Which metal can replace Al

In aluminates, the coordination number of Al is

In aluminates coordination number of Al is :

In alpha-helix structure of protein, each turn has nearly ………………….. number of amino acids.

In alpha- helix structure intramolecular hydrogen bonding takes place between

In almost all Indian metropolitan cities like Delhi, the major atmospheric pollutants is/are

Inalpha -helix , structure, polypepetide chains are folded in a

In allylic alcohol - OH group is attached to

In all green leaves and vegetables which of the following vitamin is avialable ?

In alkyl nitrites the oxygen of -O-N=O group is linked with carbon. An alkyl nitrite is :

In alkyl cyanide alkyl group attached with

In alkanline medium ClO_(2) oxidises H_(2)O_(2) to O_(2) and itself gets reduced to Cl^(-). How many moles of H_(2)O_(2) are oxidised by 1 mol of ClO_(2)?