94420 + Interview Questions in Chemistry in Class 12

1.	Assertion :- If 100 cc of 0.1N HCl is mixed with 100 cc of 0.2 N HCl, the normality of the final solution will be 0.30. Reason :- Normalities of similar solutions like HCl can be added.
Answer» If both assertion and reason are true and the reason is the correct explanation of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is FALSE. If asserrion is false but reason is true. Solution :If 100 cc of 0.1 N HCL is MIXED with 100 cc of 0.2 N HCl the normality of the FINAL solution will be 0.15. `N_(1)V_(1)+N_(2)V_(2)=N_(3)V_(3) i.e., 0.1xx100+0.2xx100` `=N_(3)xx200` or `N_(3)=(0.3xx100)/(200)=0.15`

Discussion

2.	Assertion :- Ice melts faster at higher ltitude. Reason :- At high altitude atmospheric pressure is higher.
Answer» If both ASSERTION and reason are true and the reason is the CORRECT EXPLANATION of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is false. If the assertion and reason both are false. Solution :Ice melts slowly at high because melting is favoured at a high pressure at high altitude the atmospheric pressure is LOW and so ice melts slowly.

Discussion

3.	Assertion: Identification of cathode and anode is done by the use of a thermometer. Reason: Higher is the value of reduction potential, greater would be its reducing power.
Answer» if both assertion and reason are true and the reason is the correct explanation of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is false If the assertion and reason both are false. Solution :Identificationof CATHODE and anode is done by the use of ammeter/voltmeter. Higher is the value of reduction POTENTIALS greater would be its oxidising POWER.

Discussion

4.	Assertion : Hydroxyketones are not directly used in Grignard reaction. Reason : Grignard reagents react with hydroxyl group.
Answer» If both assertion and REASON are true and the reason is the correct explanation of the assertion If both assertion and reason are true and the reason is not the correct explanation of the assertion. If assertion is true but reason is false. If the assertion and reason both are false. Solution :Hydroxy ketones are not DIRECTLY used in GRIGNARD REAGENT. Grignard reagents are very reactive. Therefore, they react with HYDROXYL group. Here both are correct.

Discussion

5.	Assertion: I Daniell cell, if concentrations of Cu^(2+) ions and Zn^(2+) ions are doubled, emf of the cell will be doubled. Reason: If concentration of ions in contact with the metal is doubled, the electrode potential is doubled.
Answer» If both assertion and reason are true, and reason is the true explanation of the assertion if both assertion and reason are true, but reason is not the true explanation of the assertion. if assertion is true, but reason is false. If both assertion and reason are false. Solution :CORRECT A. `Zn+CU^(2+)toZn^(2+)+Cu,E_(cell)=E_(cell)^(@)-(RT)/(nF)"ln"([Zn^(2+)])/([Cu^(2+)])` Thus, if `[Zn^(2+)]` and `[Cu^(2+)]` are DOUBLED, there is no effect of emf. Correct R. `Cu^(2+)+2e^(-)toCu,E=E^(@)-(RT)/(nF)"ln"(1)/([Cu^(2+)])` Thus, if `[C^(2+)]` is doubled, E is not doubled.

Discussion

6.	Assertion: Hydroxy ketones are not directly used in Grignard reaction. Reason: Grignard reagent react with hydroxyl group.
Answer» If both ASSERTION and REASON are TRUE, and reason is the true EXPLANATION of the assertion. If both assertion and reason are true, but reason is not the true explanation o the assertion. if assertion is true, but reason is false. If both assertion and reason are false. Answer :A

Discussion

7.	Assertion : Ice is less dense than liquid water. Reason: There are vacant spaces between hydrogen bonded water molecules in ice.
Answer» If both ASSERTION and reason are true and the reason is the correct explanation of the assertion if both assertion and reason are true but reason is not the correct explanation of the assertion if assertion is true but reason is false if the assertionand reason both are false Solution :It is correct that during formation of ICE from water there are vacant SPACES between hydrogen bonded molecules of of ice. Ice has a cage LIKE structure. Due to this reason Ice is less dense than liquid water. Hence both assertion and reason are true & reason are the correct explanation of assertion.

Discussion

8.	Assertion : Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal. Reason : Copper is extracted by hydrometallurgy.
Answer» Both ASSERTION and reason are true and reason is the CORRECT EXPLANATION of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is false but reason is false. Assertion is false but reason is true. Solution :Correct explanation : Only HIGHLY reactive metals are isolated by the PROCESS of electrometallurgy.

Discussion

9.	Assertion : Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal. Reason: Copper is extracted by hydrometallurgy.
Answer» Both ASSERTION and REASON are true and reason is the correct explanation of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false. Assertion is false but reason is true. Solution :In this PROCESS, salts of metal are DISSOLVED in suitable solvent LIKE water followed by reduction with more electropositive elements.

Discussion

10.	Assertion: Hydrometallurgyinvolves dissolvingthe oreina suitablereagentfollowedby precipitationbya moreelectropositivemetal. Reason: Copperisextractedbyhydrometallurgy.
Answer» Bothassertionandreason aretrueandreason is thecorrectexplanationofassertion. Both assertionandreasonaretruebutreasonis not thecorrectexplanationofassertion. Assertionistrue butreasonisfalse. Assertionis falsebutreasonistrue. SOLUTION :Correctreason.Onlylowgradcopperis extractedbyhydrometallurgywhilecopperin bulkquantities is preparedbypyrometallurgy.

Discussion

11.	Assertion: Hydrolysis of sucrose brings about a change in sign of rotation from dextro to laevo.Reason: Hydrolysis always changes the optical rotation of a compound.
Answer» If both assertion and REASON are TRUE and reason is the correct explanation of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is false. If both assertion and reason are false. Solution :SUCROSE is dextrotatory but after hydrolysis GIVES dextrorotatory glucose and laevorotatory fructose . SINCE laevorotation of fructose `(-92.4^(@))` is more than dextrorotatory of glucose `(+52.5^(@))` , hence the mixture is laevorotatory.

Discussion

12.	Assertion : Hydrolysis of methyl acetate by HCl is a pesudo first order reaction. Reason : HCl is used as catalyst in the above reaction.
Answer» Both ASSERTION and REASON are true and reason is the correct EXPLANATION of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false. Both assertion and reason are false. ANSWER :B

Discussion

13.	Assertion : Hydrolysis of ester is an example of auto-catalytic reaction. Reason : A catalyst speeds up the process without participating in the mechanism.
Answer» If both ASSERTION and reason are true and reasonis the correct explanation of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but reason is FALSE if both assertion and reason are false Solution :A CATALYST participates in the MECHANISM of the REACTION and is regenerated after the reaction.

Discussion

14.	Assertion : Hydrolysis of ester in acidic medium follows pseudo first order kinetics. Reason : Hydrolysis of ester is independent of the concentration of acid used.
Answer» Both assertion and reason are true and reason is the CORRECT explanation of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is FALSE. Both assertion and reason are false. ANSWER :A

Discussion

15.	Assertion: Hydrolysis of (-)-2-bromooctane proceeds with inversion of configuration. Reason: This reaction proceeds through the formation of a carbocations.
Answer» Assertion and REASON both are correct and reason is correct EXPLANATION of assertion. Assertion and reason both are wrong statements. Assertion is correct but reason is wrong statement. Assertion is wrong but reason is correct statement. Solution :Correct reason. REACTION proceeds by `S_(N)1` mechanism.

Discussion

16.	Assertion : Hydrogen cannot be prepared in laboratory. Reason : Hydrogen of high purity is obtained by electrolysing warm aqueous barium hydroxide between Nickel electrods.
Answer» If both ASSERTION & Reason are True & the Reason is a CORRECT EXPLANATION of the Assertion. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion. If Assertion is True but the Reason is False. If both Assertion & Reason are False. Answer :D

Discussion

17.	Assertion: Hydrazine is a neutral ligand. Reason: It has two N as donor atoms and behaves as a chelating ligand.
Answer» If assertion is TRUE but the REASON is false If assertion is false but reason is true If both assertion and reason are true and the reason is the correct explanation of assertion If both assertion and reason are true but reason is not the correct explanation of assertion Solution :`NH_(2)-NH_(2)` neutral LIGAND. It does not act as bidentate because when it accts as bidentate, because when it acts as bidentate a three membered RING (chelat complex) will be formed,that will be highely stained.

Discussion

18.	Assertion:- Hydro is used in photography. Reason:- It is a storng non-complexing agent.
Answer» If both Assertion `&` Reason are True `&` the Reason is a CORRECT EXPLANATION of the Assertion. If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion. If Assertion is True but the Reason is FALSE. If both Assertion `&` Reason are False. ANSWER :C

Discussion

19.	Assertion: Hofmann's bromamide reaction is given by primary amines. Reason: Primary aminies are more basic than secondary amines.
Answer» Both assertion and reason are wrong. Both assertion and reason are correct STATEMENTS but reason is not correct explanation of assertion. Assertion is correct statement but reason is wrong statement. Both assertion and reason are correct statements and reason is correct explanation of assertion. Solution :Correct assertion. Hofmann's bromamide REACTION is given by `1^(@)` amides. Correct reason. With `Br_(2)//NaOH`, primary amides are CONVERTED into isocyanates which pon alkaline hydrolysis give primary amines.

Discussion

20.	Assertion : HOF bond angle is higher than HOCl. Reason : Oxygen is more electronegative than chlorine.
Answer» If assertion is TRUE but the reason is false If assertion is false but reason is true If both assertion and reason are true and the reason is the correct explanation of assertion If both assertion and reason are true and the reason is not the correct explanation of assertion Solution :In `HOCl` , O is more electronegative than Cl. Hence, its will contains mores s CHARACTER in hybrid ORBITAL hence bond angle will be more than EXPECTED. Hence, bond angle is HOCl is greater than HOF.

Discussion

21.	Assertion. HOF bond angle is higher than HOCl bond angle in HOX. Reason. Oxygen is more electronegative than halogens.
Answer» If both ASSERTION and REASON are true, and reason is the correct EXPLANATION of the assertion. If both assertion and reason are TURE, but reason is not the correct explanantion of the assertion. If assertion is true, but reason is FALSE. If both assertion and reason are false Solution :Correct assertion. HOF bond angle is smaller than HOCl bond angle. Correct reason. Oxygen is more electronegative than all halogens except fluorine.

Discussion

22.	Assertion. HNO_(3) renders iron passive. Reason. Iron reacts with HNO_(3) to form ferric nitrate.
Answer» If both ASSERTION and reason are TRUE, and reason is the correct explanation of the assertion. If both assertion and reason are ture, but reason is not the correct explanantion of the assertion. If assertion is true, but reason is false. If both assertion and reason are false Solution :Correct reason. `HNO_(3)` reacts with Fe to form a thin impervious layer of ferrosoferric oxide `(FeO.Fe_(2)O_(3)-= Fe_(3)O_(4))` on the surface of iron which protects it form further action.

Discussion

23.	Assertion : HNO_3 makes iron passive. Reason : HNO_3 forms a protective layer of ferric nitrate on the surface of iron.
Answer» Both assertion and reason are CORRECT STATEMENTS, and reason is the correct explanation of the assertion. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion. Assertion is correct, but reason is wrong statement. Assertion is wrong but reason is correct statement. Solution : IRON becomes passive due to FORMATION of oxide layer on its SURFACE.

Discussion

24.	Assertion : HNO_3 is a strong acid. Reason : HNO_3 is completely ionised in solution and so has high K_a value
Answer» (A) and ( R) are TRUE and ( R) is the CORRECT EXPLANATION of (A) Both (A) and ( R) are true but ( R) does not explain (A) (A ) is true but (R ) is false Both (A) and ( R) are false Answer :A

Discussion

25.	Assertion. Higher the molal depression constant of the solvent used, higher the freezing point of the solution. Reason. Depression in freezing point does not depend on the nature of the solvent.
Answer» If both ASSERTION and reason are true, and reason is the true EXPLANATION of the assertion. If both assertion and reason are true, but reason is not the true explanation of the assertion. If assertion is true, but reason is false. If both assertion and reason are false. Solution :CORRECT A. Higher the molal depression constant of the SOLVENT used, higher is the depression freezing POINT.

Discussion

26.	Assertion : HI cannot be prepared by the reaction of KT with concentrated H_2SO_4. Reason : HI has lowest H-X bond strength among halogen acids.
Answer» Both ASSERTION and REASON are CORRECT statements, and reason is the correct EXPLANATION of the assertion. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion. Assertion is correct, but reason is WRONG statement. Assertion is wrong but reason is correct statement. Solution :(B) Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion.

Discussion

27.	Assertion : HI cannot be prepared by the raction of KI with concentrated H_(2)SO_(4). Reason : HI has lowest H-X bond strength among halogen acids.
Answer» Both assertion and REASON are correct STATEMENTS, and reason is the correct explanation of the assertion. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion. Assertion is correct, but reason is wrong statement. Both assertion and reason are wrong statement. Solution :Correct explanation. HI being a STRONG reducing agent REDUCES `H_(2)SO_(4)` to `SO_(2)` and itself gets oxidised to `I_(2) or H_(2)SO_(4)` being an oxidising agent oxidises HI to `I_(2)` .

Discussion

28.	Assertion: Hg is the only metal whichis liquid at 0^(@)C. Reason: It has very I.P. and weak metallic bond.
Answer» If both assertion and REASON are true and the reason is the CORRECT EXPLANATION of assertion If both assertion and reason are true and the reason is not the correct explanation of assertion If assertion is false but reason is true If assertion is true but the reason is false ANSWER :A

Discussion

29.	Assertion: Helium and beryllium have similar outer electronic configuration of the type ns^(2). Reason: Both are chemically inert.
Answer» If both ASSERTION and REASON are TRUE annd the reason is the correct explanation of assertion If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but the reason is false if assertion is false but the reason is true Answer :C

Discussion

30.	Assertion: helium atom has highest ionisation energy among all the element. Reason: helium is smallest atom among all the elements.
Answer» If both assertion and reason are true ANND the reason is the CORRECT EXPLANATION of assertion If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but the reason is false if assertion is false but the reason is true Answer :C

Discussion

31.	Assertion : Heatof neutralization of perchloric acid,HClO_(4) with NaOH is same as is that of HCl and NaOH. Reason : Both HCl and HClO_(4) are strong acids
Answer» If the assertion and REASON are TRUE and the reason is the correct explanation of the assertion If both assertion and reason are true but reason is not the correct explanation of the assertion If assertion is true but reason is false If the assertion and reason both are false. Answer :A

Discussion

32.	Assertion : Heat of adsorption is very high in chemisorption Reason : The force that causes chemisorption is dipole - dipole moment
Answer» (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true but (R) does not explain (A) (A) is true but (R) is FALSE Both (A) and (R) are false Answer :C

Discussion

33.	Assertion : Heat absorbed in a reaction at constant temperature and constant volume is -DeltaG. Reason : DeltaG should be negative for the reaction to be spontaneous.
Answer» If both assertion and REASON are TRUE and the reason is the correct explanation of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion If assertion is true but reason is FALSE If assertion is false but reason is true. Solution :Heat absorbed in a reaction at constant TEMPERATURE and constant volume (Qv)=E.

Discussion

34.	Assertion : HClO is a stronger acid than HBrO. Reason : Cleavage of ClO-H bond is easier than that of BrO-H bond because Cl is more electronegative than Br.
Answer» If both ASSERTION and REASON are CORRECT and reason is correct EXPLANATION for assertion. If both assertion and reason are correct but reason is not correct explanation for assertion. If assertion is correct but reason is incorrect. If both assertion and reason are incorrect. Solution :Reason is the correct explanation for assertion.

Discussion

35.	Assertion. HClO_(4) is a stronger acid than HClO_(3). Reason. Oxidation state of Cl in HClO_(4) is +7 and in HClO_(3) it is +5.
Answer» If both assertion and reason are true, and reason is the correct explanation of the assertion. If both assertion and reason are TURE, but reason is not the correct EXPLANANTION of the assertion. If assertion is true, but reason is false. If both assertion and reason are false Solution :Correct explanation. Due to higer (+7) O.S. of CL in `HClO_(4)` than in `HClO_(3)` (+5), the `ClO_(3)` part of `HClO_(4)` PULLS the electrons of the O-H more strongly than `ClO_(2)` part in `HClO_(3)`. As a result, the O-H bond in `HClO_(4)` can break more easily to liberate a proton than in `HClO_(3)` and hence `HClO_(4)` is more acidic than `HClO_(3)`.

Discussion

36.	Assertion : H_(3)PO_(4) is less acidic thanH_(3)PO_(3) Reason : Oxidation state of phosphorus in H_(3)PO_(4) lt H_(3)PO_(3)
Answer» Both assertion and reason are TRUE and reason is the CORRECT EXPLANATION of the assertion Both assertion and reason are true and reason is not the correct explanation of the assertion. Assertion is true but reason is false Both assertion and reason are false. Answer :A::B::C

Discussion

37.	Assertion : Half-life period of a reaction of first order is independent of initial concentration . Reason : Half-life period for a first order reaction t_(1//2) = (2.303)/(K) "log" 2
Answer» If both ASSERTION and reason are true and the reason is the correct EXPLANATION of the assertion . If both assertion and reason are true but reason is not the correct explanation of the assertion If assertion is true but reason is false If the assertion and reason both are false . Solution :For a first order reaction , k = `(2.303)/(t)` log `(a)/(a-X)` , where a is INITIAL CONCENTRATION and x is the amount reacted in time t . For half-life x = a/2 , t = `t_(1//2)` k = `(2.303)/(t_(1//2))` log `(a)/(a-a//2)` `t_(1//2) = (2.303)/(k)` log `2= (0.693)/(k)`.

Discussion

38.	Assertion: H_(2)S_(2)O_(8) and H_(2)SO_(5) act as an oxidising agent while H_(2)S_(2)O_(3) can't Reason: H_(2)S_(2)O_(8) and H_(2)SO_(5) both have O-O bond while in H_(2)S_(2)O_(3) molecules S=O bond is present
Answer» ANSWER :B

Discussion

39.	Assertion : H_(2)SO_(4) cannot act as reducing agent. Reason : Sulphur cannot increase its oxidation number beyond +6.
Answer» If both assertion and reason are true and the reason is the CORRECT explanation of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is false. If the assertion and reason both are false. Solution :Both assertion and reason are true and reason is the correct explanation of assertion. Maximum OXIDATION state of S is +6, it cannot exceed it. THEREFORE it can't be further oxidized as `S^(-2)` can't be REDUCED further.

Discussion

40.	Assertion : H_(2)O_(2) react with PbS to form PbSO_(4). Reason : H_(2)O_(2) is weak acid
Answer» If both Assertion & Reason are TRUE & the Reason is a correct explanation of the Assertion. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion. If Assertion is True but the Reason is False. If both Assertion & Reason are False. Answer :B

Discussion

41.	Assertion. H_(2)O is the only hydride of chalcogens which is liquid at ordinary temperature. Reason. In ice, each O atom is surrounded by two covalent bonds and two H-bonds.
Answer» If both assertion and reason are TRUE, and reason is the correct explanation of the assertion. If both assertion and reason are ture, but reason is not the correct explanantion of the assertion. If assertion is true, but reason is FALSE. If both assertion and reason are false Solution :Correct exlplanation. Because of extensive H-bonding, `H_(2)O` has HIGH b.p. and HENCE is a liquid at room temperature.

Discussion

42.	Assertion : H_(2)O is the only hydride of chalcogen family . Reason : Acidic nature of hydrides of chalcogen family increasesdown the group .
Answer» Both assertion and reason are TRUE and reason is the CORRECT explanation of the assertion Both assertion and reason are true and reason is not the correct explanation of the assertion. Assertion is true but reason is false Both assertion and reason are false. Answer :A::B::C::D

Discussion

43.	Assertion: H_(2)-O_92) fuel cell gives a constant ions, yet the overall concentration of OH^(-) ions does not chagne. Reason: In this cell, H_(2) reacts with OH^(-) ions, yet the overall concentration of OH^(-) ion does not change.
Answer» If both ASSERTION and REASON are TRUE, and reason is the true explanation of the assertion if both assertion and reason are true, but reason is not the true explanation of the assertion. if assertion is true, but reason is false. If both assertion and reason are false. Solution :Both A and R are correct andR is the correct explanation of A.

Discussion

44.	Assertion:H_(2) molecule is more stable than HEH molecule. Reason: the anti-bonding electron in the molecule destabilise it.
Answer» If both assertion and Reason are TRUE and the Reason is the correct explanation of the assertion. If both assertion and Reason are true but the reason is not the correct explanation of the assertion If assertion is true but reason is false If both assertion and reason are false. Solution :`H_(2)` molecule is more stable than `HEH` because BOND order `H_(2)=1` ad that of `HeH=(1)/(2)` (HIGHER the bond order, more is the STABILITY).

Discussion

45.	Assertion. H-S-H bond angle in H_(2)S is closer to 90^(@) but H-O-H bond angle in H_(2)O is 104.5^(@) Reason. lp-lp repulsion is stronger in H_(2)S than in H_(2)O.
Answer» If both ASSERTION and reason are true, and reason is the correct explanation of the assertion. If both assertion and reason are ture, but reason is not the correct explanantion of the assertion. If assertion is true, but reason is false. If both assertion and reason are false Solution :Correct reason. DUE to lower electronegativity of S as COMPARED to O, the bond pairs of H-S BONDS lie away from S in `H_(2)S` as compared to bond pairs of O-H bonds in `H_(2)O`. As a result, bp-bp repulsions in `H_(2)S` are WEAKER than in `H_(2)O` and hence H-S-H bond angle in `H_(2)S` is smaller `(90^(@))` than H-O-H bond angle in `H_(2)O (104.5^(@))`.

Discussion

46.	Assertion : H-bonding occurs in H_(2)O due to larger size of O-atom. Reason : The size of O-atom is larger than H-atom.
Answer» If assertion is TRUE but the reason is FALSE If assertion is false but reason is true If both assertion and reason are true and the reason is the CORRECT explanation of assertion If both assertion and reason are true and the reason is not the correct explanation of assertion Answer :A

Discussion

47.	Assertion Green edge flame rest tells presence of borate ion. Reason: Green colour of the flame is due to burining of tri ethyl borate.
Answer» If ASSERTION is TRUE but the REASON is false If assertion is false but reason is true If both assertion and reason are true and reason is the correct explanation of assertion If OTH assertion and reason are true but reason is not the correct explanation of assertion Answer :C

Discussion

48.	Assertion. Greater the value of Henry's constant of a gas in a particular solvent, greater is the solubility of the gas at the same pressure and temperature. Reason. Solubility of a gas is directly propportional to its Henry's constant at the same pressure and temperature.
Answer» If both assertion and reason are true, and reason is the true explanation of the assertion. If both assertion and reason are true, but reason is not the true explanation of the assertion. If assertion is true, but reason is false. If both assertion and reason are false. Solution :Correct A. Greater the VALUE of Henry's constant of a gas in a PARTICULAR solvent, LESS is the solubility of the gas at the same pressure and temperature. Correct R. Solubility of a gas is INVERSELY proportional to its Henry's constant at the same pressure and temperature.

Discussion

49.	Statement - I. Greater the molal depression constant of the solvent used less in the freezing point of the solution. Statement - II. Depression in freezing point depends upon the nature of the solvent.
Answer» If both ASSERTION are REASON are CORRECT and reason is correct EXPLANATION for assertion. If both assertion and reason are CORRCT but reason is not correct explanation for assertion. If assertion is corrct but reason is incorrect. If assertion and reason both are incrrect. Solution :Reason is the correct explanation for assertion.

Discussion

50.	Assertion: Graphite is an example of tetragonal crstal system. Reason: For a tetragonal system. a=bnec,alpha=beta=90^(@),gamma=120^(@)
Answer» If both assertion and REASON are TRUE and the reason is the CORRECT explanantion of the assertion If both assertion and reason are true but reason is not the correct explanation of the assertion. If assertion is true but reason is false. If the assertion and reason both are false. Solution :Graphite is hexagonal system and for TETRAGONAL all three angles are `90^(@)`.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Assertion :- If 100 cc of 0.1N HCl is mixed with 100 cc of 0.2 N HCl, the normality of the final solution will be 0.30. Reason :- Normalities of similar solutions like HCl can be added.

Assertion :- Ice melts faster at higher ltitude. Reason :- At high altitude atmospheric pressure is higher.

Assertion: Identification of cathode and anode is done by the use of a thermometer. Reason: Higher is the value of reduction potential, greater would be its reducing power.

Assertion : Hydroxyketones are not directly used in Grignard reaction. Reason : Grignard reagents react with hydroxyl group.

Assertion: I Daniell cell, if concentrations of Cu^(2+) ions and Zn^(2+) ions are doubled, emf of the cell will be doubled. Reason: If concentration of ions in contact with the metal is doubled, the electrode potential is doubled.

Assertion: Hydroxy ketones are not directly used in Grignard reaction. Reason: Grignard reagent react with hydroxyl group.

Assertion : Ice is less dense than liquid water. Reason: There are vacant spaces between hydrogen bonded water molecules in ice.

Assertion : Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal. Reason : Copper is extracted by hydrometallurgy.

Assertion : Hydrometallurgy involves dissolving the ore in a suitable reagent followed by precipitation by a more electropositive metal. Reason: Copper is extracted by hydrometallurgy.

Assertion: Hydrometallurgyinvolves dissolvingthe oreina suitablereagentfollowedby precipitationbya moreelectropositivemetal. Reason: Copperisextractedbyhydrometallurgy.

Assertion: Hydrolysis of sucrose brings about a change in sign of rotation from dextro to laevo.Reason: Hydrolysis always changes the optical rotation of a compound.

Assertion : Hydrolysis of methyl acetate by HCl is a pesudo first order reaction. Reason : HCl is used as catalyst in the above reaction.

Assertion : Hydrolysis of ester is an example of auto-catalytic reaction. Reason : A catalyst speeds up the process without participating in the mechanism.

Assertion : Hydrolysis of ester in acidic medium follows pseudo first order kinetics. Reason : Hydrolysis of ester is independent of the concentration of acid used.

Assertion: Hydrolysis of (-)-2-bromooctane proceeds with inversion of configuration. Reason: This reaction proceeds through the formation of a carbocations.

Assertion : Hydrogen cannot be prepared in laboratory. Reason : Hydrogen of high purity is obtained by electrolysing warm aqueous barium hydroxide between Nickel electrods.

Assertion: Hydrazine is a neutral ligand. Reason: It has two N as donor atoms and behaves as a chelating ligand.

Assertion:- Hydro is used in photography. Reason:- It is a storng non-complexing agent.

Assertion: Hofmann's bromamide reaction is given by primary amines. Reason: Primary aminies are more basic than secondary amines.

Assertion : HOF bond angle is higher than HOCl. Reason : Oxygen is more electronegative than chlorine.

Assertion. HOF bond angle is higher than HOCl bond angle in HOX. Reason. Oxygen is more electronegative than halogens.

Assertion. HNO_(3) renders iron passive. Reason. Iron reacts with HNO_(3) to form ferric nitrate.

Assertion : HNO_3 makes iron passive. Reason : HNO_3 forms a protective layer of ferric nitrate on the surface of iron.

Assertion : HNO_3 is a strong acid. Reason : HNO_3 is completely ionised in solution and so has high K_a value

Assertion. Higher the molal depression constant of the solvent used, higher the freezing point of the solution. Reason. Depression in freezing point does not depend on the nature of the solvent.

Assertion : HI cannot be prepared by the reaction of KT with concentrated H_2SO_4. Reason : HI has lowest H-X bond strength among halogen acids.

Assertion : HI cannot be prepared by the raction of KI with concentrated H_(2)SO_(4). Reason : HI has lowest H-X bond strength among halogen acids.

Assertion: Hg is the only metal whichis liquid at 0^(@)C. Reason: It has very I.P. and weak metallic bond.

Assertion: Helium and beryllium have similar outer electronic configuration of the type ns^(2). Reason: Both are chemically inert.

Assertion: helium atom has highest ionisation energy among all the element. Reason: helium is smallest atom among all the elements.

Assertion : Heatof neutralization of perchloric acid,HClO_(4) with NaOH is same as is that of HCl and NaOH. Reason : Both HCl and HClO_(4) are strong acids

Assertion : Heat of adsorption is very high in chemisorption Reason : The force that causes chemisorption is dipole - dipole moment

Assertion : Heat absorbed in a reaction at constant temperature and constant volume is -DeltaG. Reason : DeltaG should be negative for the reaction to be spontaneous.

Assertion : HClO is a stronger acid than HBrO. Reason : Cleavage of ClO-H bond is easier than that of BrO-H bond because Cl is more electronegative than Br.

Assertion. HClO_(4) is a stronger acid than HClO_(3). Reason. Oxidation state of Cl in HClO_(4) is +7 and in HClO_(3) it is +5.

Assertion : H_(3)PO_(4) is less acidic thanH_(3)PO_(3) Reason : Oxidation state of phosphorus in H_(3)PO_(4) lt H_(3)PO_(3)

Assertion : Half-life period of a reaction of first order is independent of initial concentration . Reason : Half-life period for a first order reaction t_(1//2) = (2.303)/(K) "log" 2

Assertion: H_(2)S_(2)O_(8) and H_(2)SO_(5) act as an oxidising agent while H_(2)S_(2)O_(3) can't Reason: H_(2)S_(2)O_(8) and H_(2)SO_(5) both have O-O bond while in H_(2)S_(2)O_(3) molecules S=O bond is present

Assertion : H_(2)SO_(4) cannot act as reducing agent. Reason : Sulphur cannot increase its oxidation number beyond +6.

Assertion : H_(2)O_(2) react with PbS to form PbSO_(4). Reason : H_(2)O_(2) is weak acid

Assertion. H_(2)O is the only hydride of chalcogens which is liquid at ordinary temperature. Reason. In ice, each O atom is surrounded by two covalent bonds and two H-bonds.

Assertion : H_(2)O is the only hydride of chalcogen family . Reason : Acidic nature of hydrides of chalcogen family increasesdown the group .

Assertion: H_(2)-O_92) fuel cell gives a constant ions, yet the overall concentration of OH^(-) ions does not chagne. Reason: In this cell, H_(2) reacts with OH^(-) ions, yet the overall concentration of OH^(-) ion does not change.

Assertion:H_(2) molecule is more stable than HEH molecule. Reason: the anti-bonding electron in the molecule destabilise it.

Assertion. H-S-H bond angle in H_(2)S is closer to 90^(@) but H-O-H bond angle in H_(2)O is 104.5^(@) Reason. lp-lp repulsion is stronger in H_(2)S than in H_(2)O.

Assertion : H-bonding occurs in H_(2)O due to larger size of O-atom. Reason : The size of O-atom is larger than H-atom.

Assertion Green edge flame rest tells presence of borate ion. Reason: Green colour of the flame is due to burining of tri ethyl borate.

Assertion. Greater the value of Henry's constant of a gas in a particular solvent, greater is the solubility of the gas at the same pressure and temperature. Reason. Solubility of a gas is directly propportional to its Henry's constant at the same pressure and temperature.

Statement - I. Greater the molal depression constant of the solvent used less in the freezing point of the solution. Statement - II. Depression in freezing point depends upon the nature of the solvent.

Assertion: Graphite is an example of tetragonal crstal system. Reason: For a tetragonal system. a=bnec,alpha=beta=90^(@),gamma=120^(@)