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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. |
Bleaching powder turns red litmus to litmus to blue and finally white, it is due to |
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Answer» `OH^(-)` 
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| 2. |
Bleaching powder loses its power on keeping for a long time because |
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Answer» it changes into CALCIUM hypochlorate |
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| 3. |
Bleaching powder loses its power on keeping for a long time because... |
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Answer» it CHANGES into CALCIUM HYPOCHLORITE. |
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| 4. |
Bleaching powder is obtained by the reaction chlorine with |
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Answer» QUICK lime |
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| 5. |
Bleaching powder is a compound having the molecular formula |
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Answer» `CaOCl_(3)` |
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| 7. |
Bleaching powder and bleach solution are produced on a large scale and used in several household products. The affectiveness of bleach solution is often measured by iodometry. 25 ml of household bleach solution is |
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Answer» 0.48 M `eq_(Cl_(2))` LIBERATED = `(4.8)/(1000)xx0.25` `therefore` moles of `Cl_(2)=(48xx0.25)/(1000xx2)` `therefore` moles of bleaching powder = `6xx10^(-3)` `therefore` MOLARITY = `(6xx10^(-3))/(0.025)=0.24M` |
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| 8. |
Bleaching powder and bleach solution are produced on a large scale and used in several household products. The effectiveness of bleach solution is often measured by iodometry. Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is : |
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Answer» `Cl_(2)O` `to CA^(2+)(Ocl^(-))(Cl^(-))` It is SALT of hypochlorous acid HOCl, ANHYDRIDE of HOCl is `Cl_(2)O` `2HOCl to Cl_(2)O+H_(2)O` |
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| 9. |
Bleaching powder and bleach solution are produced on a large scale and used in several household products. The effectiveness of bleach solution is often measured by iodometry. 25 mL of household bleach solution was mixed with 30 mL of 0.50 M KI and 10 mL of 4 N acetic acid. In the titration of the liberated iodine, 48 mL of 0.25 N Na_(2)S_(2)O_(3) was used to reach the end point. The molarity of the household bleach solution is : |
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Answer» 0.48 M `underset((25 mL))(H_(2)O_(2))+underset(0.5 M 30 mL)(2I^(-))+underset(4 N 10 mL)(2H^(+)) to I_(2)+2H_(2)O` `I_(2)+underset(0.25 N 48 mL)(2Na_(2)S_(2)O_(3)) to 2 NaI+Na_(2)S_(4)O_(6)` Normality and molarity of `CH_(3)COOH(H^(+)) " and" Na_(2)S_(2)O_(3)` will be equal. NUMBER of moles of `I_(2)=(1)/(2)xx " Number of moles of " Na_(2)S_(2)O_(3)` `=(1)/(2)[(MV)/(1000)]=(1)/(2)[(0.25xx48)/(1000)]=6XX10^(-3)` Number of moles of `H_(2)O_(2)`= Number of moles of `I_(2)` `=6xx10^(-3)` Molarity of `H_(2)O_(2)=(n_(H_(2)O_(2)))/(V)xx1000` `=(6xx10^(-3))/(25)xx1000` =0.24 |
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| 10. |
Bleaching powder and bleach solution ar produced on a large scale and used in several household porduct the effectiveness of bleach solution is often measured iodometry Bleaching powder contais a salt of an oxoacid as one of its components the anhydrode of that oxacid is |
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Answer» `CI_(2)O` `2HOCIrarrH_(2)+CI_(2)O` |
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| 11. |
Bleaching of paper with hydrogen peroxide is preferred now-a-days Why? |
| Answer» Solution :Paper and pulp were bleached EARLIER with chlorine gas or with bleaching POWDER.The gas or powder has pungent odour. During the process, the bleaching agent is REDUCED to harmful hydrogen chloride . Bleaching with hydrogen peroxide is preferred because , it is a MILD and SOFT bleach. Both the belching agent and by-products are not pollutants. | |
| 13. |
Blasting galetin is prepared by mixing nitro-gylcerine with |
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Answer» saw dust and ammonium nitrate |
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| 14. |
Blackened oil painting can be restored into original form by the action of |
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Answer» Chlorine |
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| 15. |
Black lead is |
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Answer» Diamond |
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| 16. |
Bismuth (V) is a stronger oxidising agent than Sb (V). Explain. |
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Answer» Solution :Due to inert pair effect, the stabilityof +5 oxisdation STATES decresase down the group, i.e., +5 OXIDATION state of Sb is more stable than +5 oxideation state of Bi. Thus, `Bi^(5+)` has a higher tendency to accept a pair of elections than `Sb^(5+)` i.e., `Bi^(5+)+2e^(-)toBi^(3+)`, higher tendency to accept ELECTRONS , stronger oxidising agent `Sb^(5+)+2e^(_)toSb^(3+),` LOWER tendancy to accept electrons , weakder oxidising agent In other words, Bi (V) is a stronger oxidising agent than Sb (V). |
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| 17. |
Bismuth is a strong oxidising agent in the pentavalent state. Or Pentavalent bismuth is a strong oxidising agent. |
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Answer» SOLUTION :Since the inert PAIR EFFECT is very prominent in Bi, therefore, its +5 oxidation state is much less stable than its +3 oxidation state. In other words, bismuth in the pentavalent state can easilly accept two electrons and thus GETS reduced to more stable trivalent bismuth. `Bi^(5+)+2e^(-)toBi^(3+)` Therefore, Bi in the pentavalent state acts as a STRONG oxidising agent. |
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| 18. |
Birch reduction : Birch reduction involves controlled reduction of alkynes & atomic compounds in the preseance of alkali metals & alcohol. It provides a method to sterospecifically prepare alkenes of E- configuration R - C -= C -R overset(M,EtOH)to The characteristic type of reaction of alkynes is electrophilic addition reaction like alkenes. The alkynes show various reactions such as halagenation, hydration, hydrogenation etc... 0.40 5g sample of hydrocarbon occupies 229.54ml at 100^(@)C & 1 atm pressure. It decolouses KMnO_4 & Br_2water. When it reacts with dil. H_2SO_4 under appropriate conditions methyl ethyl, ketone is formed The hydrocarbon is |
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Answer» More REACTIVE than butane towards `Br_2 // C Cl_4 & H_2// PT ` |
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| 19. |
Birch reduction : Birch reduction involves controlled reduction of alkynes & atomic compounds in the preseance of alkali metals & alcohol. It provides a method to sterospecifically prepare alkenes of E- configuration R - C -= C -R overset(M,EtOH)to The characteristic type of reaction of alkynes is electrophilic addition reaction like alkenes. The alkynes show various reactions such as halagenation, hydration, hydrogenation etc... 0.40 5g sample of hydrocarbon occupies 229.54ml at 100^(@)C & 1 atm pressure. It decolouses KMnO_4 & Br_2water. When it reacts with dil. H_2SO_4 under appropriate conditions methyl ethyl, ketone is formed The hydrocarbon exists in (structural isomer) |
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Answer» 8 ISOMERIC FORMS 
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| 20. |
Birch reduction : Birch reduction involves controlled reduction of alkynes & atomic compounds in the preseance of alkali metals & alcohol. It provides a method to sterospecifically prepare alkenes of E- configuration R - C -= C -R overset(M,EtOH)to The characteristic type of reaction of alkynes is electrophilic addition reaction like alkenes. The alkynes show various reactions such as halagenation, hydration, hydrogenation etc... 0.40 5g sample of hydrocarbon occupies 229.54ml at 100^(@)C & 1 atm pressure. It decolouses KMnO_4 & Br_2water. When it reacts with dil. H_2SO_4 under appropriate conditions methyl ethyl, ketone is formed The molecular formula of the hydrocarbon is |
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Answer» `C_4H_6` |
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| 21. |
Biomass gasification rather than coal gasification can be used to control environmental pollution Justify ? |
| Answer» Solution :During COAL gasification , combustion of coal produces green HOUSE GASES such as `CO_(2)` which causes environmental pollution (or global warming) . But during biomass PRODUCTION as well as biomass gasification equal quantities of `CO_(2)` are used up thereby producing negligilbe environmental pollution. | |
| 22. |
Biogas is used in the production of ....... and its biproduct is used as ......... |
| Answer» SOLUTION :ELECTRICITY, FERTILIZER | |
| 23. |
Biogas and producer gas are made up of |
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Answer» BIOGAS contains `CO_(2)` BAT producer gas does not |
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| 24. |
Biodegrafdable pollutant is |
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Answer» PLASTIC |
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| 25. |
Biodegradable materials are |
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Answer» Those which SPOIL the BIOLOGICAL environment |
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| 26. |
Biochemical oxygen demand values of our water samples A,B,C and D are respectively 50 ppm, 100 ppm, 150 ppm and 40 ppm. Arrange them in the descending order of their purity. |
| Answer» Solution :More the BOD value, more the extent of pollution and LESS the purity of water. Thus purity of water SAMPLES is in the order `D GT A gt B gt C` | |
| 27. |
Biochemical oxygen demand values of four water samples P, Q, R and S are respectively 100 ppm, 50 ppm, 150 ppm and 10 ppm. Arrange them in the descending order of their purity. |
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Answer» Solution :More the BOD VALUE, more the extent of pollution and less the PURITY of water. Thus purity of water SAMPLES is in the order `S GT Q gt P gt R`. |
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| 28. |
Biochemical oxygen Demand value less than 5 ppm indicates a water sample to be .... |
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Answer» highly POLLUTED |
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| 29. |
Biochemical oxygen Demand value less than 5 ppm indicates a water sample to be ...... |
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Answer» HIGHLY polluted |
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| 30. |
Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water BOD value less than 5 ppm Indicates a water sample to be _____ |
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Answer» rich in DISSOLVED oxygen |
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| 31. |
Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be ………………. . |
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Answer» rich in dissolved oxygen. The BOD is less than 5 ppm then water is considered to be PURE. If BOD is more than 17 ppm then water is highly polluted. Thus, the water having BOD less then 5 ppm is rich in dissolved oxygen. |
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| 32. |
Bio-degradable pollutant is |
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Answer» Domestic WASTE |
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| 33. |
BiCI_(3) overset(KI)rarr Black ppt. (M) overset("excess" KI)rarr Soluble complex (N) Find the number of moles of I^(-) ions involved for the formation of one mole of (N). |
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Answer» |
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| 35. |
Bhopal Gas Tragedy is case of ...... |
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Answer» THERMAL POLLUTION |
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| 36. |
BH_(4)^(-)and NH_(4)^(+) are isolobal . Explain. |
| Answer» Solution :Both have TETRAHEDRAL shapes, i.e., FOUR lobes of `SP^(3)`hybridizedorbitals . | |
| 37. |
BF_(3) molecule has planar structure. Correct explanation for this is |
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Answer» `BF_(3)` is `SP^(3)` hybridised |
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| 38. |
BF_(3) is used as a catalyst in Friedel-Craft alkylation and acylation reaction because it is a……… |
| Answer» Answer :A | |
| 39. |
BF_(3) is used as a catalyst in various organic reactions because |
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Answer» it is a STRONG REDUCING agent |
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| 40. |
BF_(3) is |
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Answer» Electron - DEFICIENT compound `underset("EXCITED state")(B)-underset(sp^(2))(ubrace(2s^(1)2p_(x)^(1)2p_(y)^(1))) 2p_(z)^(0)` Since the octet asround B is incomplete, it behaves as an electron - deficient compound. `BF_(3)` can accept a pair of electron from some other ion/molecule in vacant 2p orbital and thus behave as a Lewis acid. |
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| 41. |
BF_(3) exist monomer but not dimer because: |
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Answer» BORON cannot COORDINATE with FOUR fluorine atoms to form dimer |
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| 42. |
BF_(3)existsas discretemoleculesbut BH_(3) existsas dimer. Explain . |
Answer» Solution :Due to `ppi-ppi` backbonding, the LONE pairof electronsof F is donatedto the B-atom. This delocalization reducesthe deficiency ofelectrons on Bthereby INCREASING the stability of `BF_(3)` MOLECULE.  Due to absenceof lone pair of electrons on H-atom, this compensationdoes not occurin `BH_(3)`. In otherwords, electron deficiency of B stays and HENCE to reduce its electron deficiency, `BBH_(3)` dimerises to form `B_(2)H_(6)`. |
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| 43. |
BF_3 does not have proton but still acts as an acid and reacts with NH_3 Why is it so ? What type of bond is formed between the two ? |
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Answer» Solution :`BF_3`is an electron DEFICIENT MOLECULE and so ACTS as Lewis acid. `ddotNH_3` has ONE lone pair which it can donate to `BF_3` and form a COORDINATE bond. So, `NH_3` acts as a Lewis base. Comment `H_3N: to BE_3` |
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| 45. |
BF_(3)does not have proton but still acts as an acid and reacts with NH_(3). Why is it so ? What type of bond is formed between the two ? |
| Answer» Solution :`BF_(3)` is ELECTRON deficient and HENCE ACTS as Lewis ACID. : `NH_(3)` has one lone pair which it can donate to `BF_(3)` and form a coordinate bond. Hence, `NH_(3)` acts as a Lewis base `(H_(3)N : rarr BF_(3))`. | |
| 46. |
BF_3 and NH_3 are ….. In the reaction BF_3+NH_3 to BF_3 larr NH_3. |
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Answer» Conjugate ACID BASE  Nitrogen of ammonia donate electron pair. So, it is Lewis base and empty orbital of boron accept `E^-` pair, so it is Lewis acid. |
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| 47. |
BF_(3) acts as acid according to the concept of |
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Answer» Lewis |
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| 48. |
BF_3 |
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Answer» Electron - deficient compound `underset("Excited state")(B)ubrace(-2s^(1)2p_(x)^(1)2p_(y)^(1))2p_z^0` Since the OCTET around B is incomplete, it behaves as an electron-deficient compound. `BF_3`can accept a pair of electron from some other ion/molecule in vacant 2p orbital and thus behave as a Lewis acid . |
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| 49. |
Beyond 2x ppm the oxides of nitrogen can effect the plants, which can not perform photosynthe sis. The value of x is _____ |
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Answer» |
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