Explore topic-wise InterviewSolutions in Current Affairs.

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.

Considerthe following reaction Nitrite + acetic acid + thioures rarr N_(2) + SCoverset(Θ)N + 2H_(2)O Formationof the product in the reaction cannot beidentified by

Answer»

`FaCI_(3)//dil, HCI` when blood -RED colour appears
`FaCI_(3)//dil, HCI` when BLUE colour appears
`K_(2)Cr_(2)O_(7) ,HCI` when green colour appears
`KMnO_(4)//HCI` when colourlesssolutionis formed

Answer :b,c,d
Discussion
2.

Consider the following reaction occuring in basic medium 2MnO_(4)^(-) + Br^(-)(aq) to2MnO_(2) (s) + BrO_(3)^(-) (aq) Howthe abovereactioncan bebalancedfurther ?

Answer»

By adding `2 OH^(-)` ions on RIGHT side
By adding one `H_(2)O` MOLECULE to left side
By adding `2H^(+)` ions on right side
Both (a) and (B)

Solution :Sincereaction is occuringinbasic medium THEREFORE`2 OH^ -`areaddedon rightside.
`2 Mn O_4 ^ -(aq )+Br ^ -(aq )to2 Mn O_ 2(s )+ Br O_3 ^ -( aq)+2 OH ^ -( aq ) `
Now,hydrogenatoms canbebalancedby addingone` H _ 2O `moleculeto theleftside
`2 MnO_4 ^ -(aq )+ Br ^ -(aq )+ H _ 2 O( l)to2 MnO_ 2 ( s )+Br O_ 3 ( aq )+2OH ^ (-)(aq ) `
Discussion
3.

Consider the following reaction, Nitrite + Acetic acid + Thiourea to Na_(2) uarr + HSCN +2H_(2)O. Formation of the product in the above reaction can be identified by :

Answer»

`FeCl_(3)//` dilute HCl, when blood red colour appears.
`FeCl_(3)//` dilute HCl, when blue colour appears.
`K_(2)Cr_(2)O_(7)// HCl`, when GREEN colour appears.
`KMnO_(4)// HCl`, when colourless solution is formed.

Answer :A
Discussion
4.

Consider the following reaction : Na_(2)SO_(3) + S overset("Boiling")underset(H_(2)O) to X (Colourless liquid) AgBr overset("Excess")to Y (Soluble complex) X + Cl_(2) + H_(2)O (l) overset("Boiling")underset(H_(2)O)to Z + HCl The (X), (Y) and (Z) are respectively

Answer»

`Na_(2)S_(4)O_(6), [Ag(S_(2)O_(3))_(2)]^(2-), NaHSO_(4)`
`Na_(2)S_(2)O_(3), [Ag(S_(2)O_(3))_(2)]^(3-), NaHSO_(4)`
`Na_(2)S_(4)O_(6), [Ag(S_(2)O_(3))_(2)]^(3-), NaHSO_(4)`
`Na_(2)S_(3)O_(3), [Ag(S_(2)O_(3))_(2)]^(3-), Na_(2)SO_(4)`

Solution :`Na_(2)S_(2)O_(3) + S OVERSET("Boiling")underset(H_(2)O)to Na_(2)S_(2)O_(3)[X]`
`AgBr + 2Na_(2)S_(2)O_(3) to underset("SOLUBLE complex Y")(Na_(3)[Ag(S_(2)O_(3))_(2)]) + NaBr`
`Na_(2)S_(2)O_(3) + 4Cl_(2) + 5H_(2)O overset("Boiling")to 2NaHSO_(4) + 8HCl`
Discussion
5.

Consider the following reaction Major product B is

Answer»




SOLUTION :CARBOXYLIC acid undergoes HELL - volhard ZELINSKY reaction in presence of `Br_2` /red -P
Discussion
6.

Consider the following reaction N_(2(g))+3H_(2(g))to2NH_(3(g)). The rate of the reaction in terms in terms of N_(2) at T(k) is -(d[N_(2)])/(dt)=0.02mole "lit"^(-1) "sec"^(-1). What is the value of -(d[H_(2)])/(dt) (in mole "lit"^(-1)"sec"^(-1)) at the same temperature?

Answer»

`0.02`
`50`
`0.06`
`0.04`

ANSWER :C
Discussion
7.

Consider the following reaction: If (P) on heating isomerizes to (Q). What is the structure of (Q) ?

Answer»




ANSWER :B
Discussion
8.

Consider the following reactionIf r_(1) is the rate of reaction and r_(2) is the rate of racemisation then which of the following relation is true ?

Answer»

`r_(1)=r_(2)`
`r_(1)=2r_(2)`
`r_(2)=2r_(1)`
`r_(2)=4r_(1)`

Solution :The above reaction follows `S_(N)2` PATH. The formation of product with radioactive iodine `(""^(131)I)` is a mirror image of the reactant. THUS, they are enantiomers of each other.
If 100 molecules of reactants are assumed to be taken, initially, then racemisation will be completed as SOON as 50% of the molecules of the reactants are consumed. Thus, racemisation takes place at a double rate than of reaction. Thus, `r_(2)=2r_(1)`.
Discussion
9.

Consider the following reaction: (i) O_((g))+e^(-) to O_((g))^(-),DeltaH_(1) (ii) F_((g))+e^(-) to F_((g))^(-),DeltaH_(2) (iii) Cl_((g))+e^(-) to Cl_((g))^(-),DeltaH_(3) (iv) O_((g))^(-) +e^(-) to O_((g))^(2-),DeltaH_(4) then according to given information the correct statement is/are:

Answer»

`DeltaH_(3)` is more NEGATIVE than `DeltaH_(1) and DeltaH_(2)`
`DeltaH_(1)` is LESS negative than `DeltaH_(2)`
`DeltaH_(1),DeltaH_(2) and DeltaH_(3)` are negative whereas `DeltaH_(4)` is positive
`DeltaH_(1) and DeltaH_(3)` are negative whereas `DeltaH_(2) and DeltaH_(4)` positive

Solution :`DeltaH_(1),DeltaH_(2) and DeltaH_(3)` are negative whereas `DeltaH_(4)` is positive.
Discussion
10.

Consider the following reaction:Identify product (P) and (Q) from the folowing compounds:

Answer»

<P>P = R, Q = S
P = S, Q = S
P = S, Q = R
P =R, Q = R

Answer :A
Discussion
11.

Consider the following reaction H_(3)C-underset(D)underset(|)(C)H-underset(CH_(3))underset(|)(C)H-CH_(3)+overset(*)(B)rto'X'+HBr Identify the structrue of the major product 'X'

Answer»

`H_(3)C-underset(D)underset(|)(C)H-underset(CH_(3))underset(|)(C)H-overset(*)(C)H_(2)`<BR>`H_(3)C-underset(D)underset(|)(C)H-underset(CH_(3))underset(|)overset(*)(C)-CH_(3)`
`H_(3)C-underset(D)underset(|)overset(*)(C)-underset(CH_(3))underset(|)(CH)-CH_(3)`
`H_(3)C-overset(*)(CH)-underset(C)underset(|)(C)H-CH_(3)`

Solution :`Br^(*)` is LESS reactive annd more selective and so the most stable free RADICAL `(3^(@))` will be the MAJOR product.
Discussion
12.

Consider the following reaction : H_(3)C-underset(D)underset(|)(C )H-underset(CH_(3))underset("|")("C")H-CH_(3)+Br^(•)rarr 'X'+HBr Identify the structure of the major product 'X'

Answer»

`H_(3)C-underset(D)underset(|)(C )H-underset(CH_(3))underset("|")("C")H-overset(•)(C )H_(2)`
`H_(3)C-underset(D)underset(|)(C )H-underset(CH_(3))underset("|")overset(•)("C")-CH_(3)`
`H_(3)C-overset(•)(C )-underset(CH_(3))underset("|")("C")H-CH_(3)`
`H_(3)C-overset(•)(C )H-underset(CH_(3))underset("|")("C")H-CH_(3)`

SOLUTION :A `3^(@)` carbon FREE RADICAL is most STABLE.
Discussion
13.

Consider the following reaction H_3C-undersetundersetD|CH-undersetunderset(CH_3)|CH-CH_3+Br to X + HBr . Identify the structure of the major product X

Answer»

`H_3C-undersetunderset(D)(|)CH-undersetunderset(CH_3)|CH-overset(DOT)CH_2`
`H_3C-undersetundersetD|CH-undersetunderset(CH_3)|overset(dot)C-CH_3`
`H_3C-undersetundersetD|overset(dot)C-undersetunderset(CH_3)|CH-CH_3`
`H_3C-overset(dot)CH-undersetunderset(CH_3)|CH-CH_3`

Solution :`CH_3-undersetunderset(D)(|)CH-undersetunderset(CH_3)|overset(dot)C-CH_3` is more stable fre radical among all other FREE RADICALS because t-ALKYL free-radical is more stable than secondary or PRIMARY alkyl free radical (based upon hyperconjugation).
Discussion
14.

Consider the following reaction: H_(2)O_(2) to H_(2)O + 1/2O_(2) to which I^(-) was added, A large foaming mass of bubbles was formed. The following mechanism has been proposed for this reaction. H_(2)O_(2) + I^(-) to H_(2)O + IO (slow) H_(2)O + IO^(-) to H_(2) + 1/2O_(2) + I^(-) (fast) The function of I^(-) in this reaction is to:

Answer»

raise the `DeltaH` of the PRODUCTS.
LOWER the `DELTAG` between reactants and products.
INCREASE the concentration of products.
Lower the activation ENERGY.

Answer :D
Discussion
15.

Consider the following reaction Glucose overset("Reagent")rarr"Mannose" The above reaction is known as

Answer»

Anomerisation
Recemisation
Epimerisation
Conversion

Answer :C
Discussion
16.

Consider the following reaction for2NO_(2(g)) + F_(2(g)) rarr 2NO_2F_((g)). The expression for the rate of reaction in terms of the rate of change of partial pressures of reactant and product is/are

Answer»

`rate=-1//2[DP(NO_2)//DT]`
`rate=1//2[dp(NO_2)//dt]`
`rate=-1//2[dp(NO_2F)//dt]`
`rate=1//2[dp(NO_2F)//dt]`

SOLUTION :`rate=-1//2[dp(NO_2)//dt]` , d `rate=1//2[dp(NO_2F)//dt]`
Discussion
17.

Consider the following reaction for 2 NO_(2) (g) + F_(2) (g) to2NO_(2) F(g) . The expression for the rate of reaction in terms of the rate of change of partial pressures of reactant and product is /are

Answer»

RATE = `-1//2`[DP `(NO_(2))`/dt ]
Rate = `1//2` [dp `(NO_(2))`/dt]
Rate = `-1//2` [dp `(NO_(2)F)`/dt]
Rate = `1//2` [dp `(NO_(2)F)`/dt]

ANSWER :AD
Discussion
18.

Consider the following reaction : Cu (s) + 2Ag^+ (aq) to2Ag (s) + Cu^(2+) (aq) (i) Depict the galvanic cell in which the given reaction takes palce. (ii) Give the direction of flow of current (iii) Write the half-cell reactions taking place at the cathode and anode.

Answer»

SOLUTION :(i) The cell may be depicted as under
`Cu(s) | Cu^(2+) (aq) || AG^(+) (aq) | Ag(s)`
(II)Current will flow from silver to copper electrode in the external circuit.
(III) At CATHODE: `2Ag^(+) (aq) + 2e^(-) to 2Ag (s)`
At anode: `Cu(s) to Cu^(2+) (aq) + 2e^(-)`
Discussion
19.

Consider the following reaction : CH_(4)+2O_(2) to CO_(2) + 2H_(2)O Which of the following about the reaction given below is/are correct ? 1. Carbon is oxidized ( कार्बन का ऑक्सीकरण ) 2. Hydrogen is oxidized ( हइड्रोजन का ऑक्सीकरण ) 3. Hydrogen is reduced ( हाईड्रोजन का अपचयन ) 4. Carbon is reducedSelect the correct answer using the code given below :

Answer»

1 only
1 and 2 only
2 and 3 only
2 and 4 only

Solution :Oxidation : Gain of oxygen or LOSS of hydrogen, Loss of electrons or increase in oxidation state Reduction: Gain of hydrogen or loss of oxygen, Gain of electrons or DECREASE in oxidation state . In the combustion of methane, carbon LOSES hydrogen and gains oxygen, so it is being oxidized. Oxygen gains hydrogen (and carbon) , so it is being reduced. Hydrogen gains oxygen (and loses carbon), so it is being oxidized.
Discussion
20.

Consider the following reaction, CH_(3)CHO + CH_(2)(COOH)_(2)overset("Pyridine")underset(Delta)rarr A A is

Answer»

`CH_(3)COOH`
`CH_(3)CH_(2)COOH`
`CH_(3)CH=CHCOOH`
`HOOC-CH=CH-COOH`

SOLUTION :
Discussion
21.

Consider the following reaction, CH_3COOH undersetrarr(CaCO_3) A undersetrarr(heat) B compound B is:

Answer»

An ETHER
An ALCOHOL
An aldehyde
A KETONE

ANSWER :D
Discussion
22.

consider the following reaction , CH_3Br+ Mg undersetrarr(Ether) Aundersetrarr(HCHO) BundersetrarrHOH C compound C is:

Answer»

ACETIC ACID
Acetaldehyde
Ethyl alcohol
FORMIC acid

ANSWER :C
Discussion
23.

consider the following reaction , CH_3Br + Mg undersetrarr(Ether) Aundersetrarr(HCHO) BundersetrarrHOH C compound C is:

Answer»

Acetic ACID
Acetaldehyde
Ethyl alcohol
FORMIC acid

ANSWER :C
Discussion
24.

Consider the following reaction CH_(3)-underset(D)underset(|)(C)H-underset(CH_(3))underset(|)(C)H-CH_(3)-overset(**)(B)rto overset(**)(X)+HBr The structure of overset(**)(X) is

Answer»

`CH_(3)-UNDERSET(D)underset(|)(C)H-underset(CH_(3))underset(|)(C)H-overset(**)(C)H_(2)`
`CH_(3)-underset(D)underset(|)(C)H-underset(CH_(3))underset(|)(overset(**)(C)-CH_(3)`
`CH_(3)-underset(D)underset(|)(overset(**)(C)-underset(CH_(3))underset(|)(C)H-CH_(3)`
`CH_(3)-overset(**)(C)H-underset(CH_(3))underset(|)(C)H-CH_(3)`.

Solution :`CH_(3)-underset(D)underset(|)((C)H-underset(CH_(3))underset(|)overset(**)(C)-CH_(3)` (tertiary free radical) is MAXIMUM. Stable DUE to hyperconfiguration.
Discussion
25.

Considerthe followingreaction CH_(3)- CONH_(2) overset(I)to CH_(3)-NH_(2) overset(II) to CH_(3)NC

Answer»

REACTIONI is calledHofmann's aminereaction
ReactionII is calledcarbyl aminereaction
REACTION I and II are HOFMANN reactions
Both 'a' and 'b'are correctstatements.

Answer :D
Discussion
26.

Consider the following reaction : C_(6)H_(5)-underset((R))underset(H) underset(|)overset(CH_(3)) overset(|)C-Cl+C_(2)H_(5)overset(o+)OtoC_(2)H_(5)O-underset(100% (S)"form") underset(H)underset(|)overset(CH_(3))overset(|)C-C_(5)H_(5) In the given C_(6)H_(5)- overset(* *)underset(* *)S-CH_(2)-overset(H)overset(|)underset(CH_(3))underset(|)C-Br+C_(2)H_(5)overset(o+)O to (P) the product is :

Answer»

`C_(6)H_(5)- overset(* *)UNDERSET(* *)S-underset((S))(CH_(2))-overset(H)overset(|)underset(CH_(3))underset(|)C-OH`
`HO-overset(H)overset(|)underset(CH_(3)(S))underset(|)C-underset((R))(CH_(2))-S-C_(5)H_(5)`
`C_(6)H_(5)- overset(* *)underset(* *)S-underset((S))(CH_(2))-overset(H)overset(|)underset(CH_(3))underset(|)C-OC_(2)H_(5)`
`C_(2)H_(5)O-overset(H)overset(|)underset(CH_(3)(S))underset(|)C-CH_(2)-S-C_(6)H_(5)`

ANSWER :C
Discussion
27.

Consider the following reaction : C_(6)H_(5)-underset((R))underset(H) underset(|)overset(CH_(3)) overset(|)C-Cl+C_(2)H_(5)overset(o+)OtoC_(2)H_(5)O-underset(100% (S)"form") underset(H)underset(|)overset(CH_(3))overset(|)C-C_(5)H_(5) Which statement is not correct ?

Answer»

`S_(N)2` reaction is first ORDER with respect to the substrate and first order with respect to nucleophile
Presence of hetero atom at `ALPHA` carbon increases the reactivity of substrate
Presence of electron withdrawing group at `alpha`- carbon decreases reactivity
Presence of `PI` bond on `alpha` carbon decreases reactivity of substrate

Answer :C
Discussion
28.

Consider the following reaction: C_6H_5-underset(H)underset(|)overset(CH_3)overset(|)C-Br+H_2Oto OH-underset(H)underset(|)overset(CH_3)overset(|)C-C_6H_5+HBr The reaction proceeds with 98% racemistation. The reaction may follow

Answer»

`S_(N^1)` MECHANISM
`S_(N^2)` mechanism
E1 mechanism
E2 mechanism

Solution :`S_(N^1)` REACTION PROCEEDS with RACEMISATION.
Discussion
29.

Consider the following reaction C_(2)H_(5)OH overset(PCl_(5)) to X overset("alc KOH") to Y overset("alc H_(2)O|H^(+)) to Z X, Y and Z respectively are _________

Answer»

`C_(2)H_(5)CL,CH_(2)=CH_(2)wedgeOH`
`C_(2)H_(4),C_(2)H_(5)COCL,C_(2)H_(5)OH`
`CH3COCl, CH2=CH2,wedgeOH`
`C_(2)H_(5)Cl,wedgeOH, CH_(2)=CH_(2)`

Answer :A
Discussion
30.

Consider the following reaction C_(2)H_(5)I underset(X)overset(Delta)to (Pleasant smelling liqluid), X is

Answer»

Sodium
Dry SILVER oxide
ETHYL CHLORIDE
Dry silver powder

Answer :B
Discussion
31.

Consider the following reaction C_(2)H_(5)Cl+AgCNoverset(EtOH//H_(2)O)toX(major) Which one of the following statement is true for X

Answer»

It gives propionic ACID on hydrolysis
It has an ester FUNCTIONAL group
It has a nitrogen linked to ETHYL carbon
It has a CYANIDE group

Answer :C
Discussion
32.

Consider the following reaction : C_(2)H_(5) OH + H_(2) SO_(4) rarr Product Among the following, which one cannot be formed as a product under any conditions ?

Answer»

Ethylene
Acetylene
DIETHYL ether
Ethyl-hydrogen sulphate

Solution :Acetylene is not formed by TREATING ETHANOL with `H_(2)SO_(4)` under any conditions.
Discussion
33.

Consider the following reaction at equilibrium: NH_4HS(s)

Answer»

Equilibrium SHIFTS in the BACKWARD direction
Equilibrium shifts in the FORWARD direction
Equilibrium REMAINS unaffected
The value of K is increased

Answer :C
Discussion
34.

Consider the following reaction at certain temperature : H_(2) (g) + Cl_(2) (g) hArr 2HCl (g) The mixing of 1 mol of H_(2) with 4 moles of Cl_(2) from x moles of HCl at equilibrium. If we add 5 moles of H_(2) at equilibrium then another 2x moles of HCl are produced. Then find K_("eq") for above reaction.

Answer»


Solution :`{:(,H_(2) (g),+,Cl_(2) (g),hArr,2HCl (g),,),("INITIALLY",1,,4,,-,,),("Equilibrium",1 - (X)/(2),,4 - (x)/(2),,x,,),("New Equilibrium",6 - (3x)/(2),,4 - (3x)/(2),,3x,["After adding 5 moles of" H_(2)],):}`
`K_(C) = (x^(2))/((1 - (x)/(2))(4 - (x)/(2))) = ((3x)^(2))/((4 - (3x)/(2)) (6 - (3x)/(2)))`
`x = 1.6`
`K_(eq) = (1.6 xx 1.6)/((1 - (1.6)/(2))(4 - (1.6)/(2)))`
`K_(eq) = 4`
Discussion
35.

Consider the following reaction at 1000^(@)C Zn_((s)+(1)/(2)O_(2(g)) to ZnO "" DeltaG^(@)=-3690KJ//"mol" C+(1)/(2)O_(2) to CO(g) "" DeltaG^(@)=460KJ//"mol" Choose the correct statement.

Answer»

ZINC can be oxidised by
ZnO can be reduced by graphite
Botha and h are true
Botha and b are false

Solution :FORMATION of CO ASSOCIATED with greater `-ve DeltaG^(0)` values than `DeltaG^(0)` values of formation of ZnO
`:.` ZnO` is reduced by .C. at
Discussion
36.

Consider the followingreaction at 1000^(@)C (A) Zn (s) + (1)/(2) O_(2) (g) rarr ZnO(s), Delta G^(Ө) = - 360 kJ mol^(-1) (B) C (s) + (1)/(2) O_(2) (g) rarr OO(g), Delta G^(Ө) = - 460 kJ mol^(-1) Choosethe correct statement at 1000^(@)C

Answer»

ZnO is more stable than CO
ZnO can be reduced to ZN by C
ZnO and CO are formed at EQUAL rate
ZnO cannot be reduced to Zn by C

Answer :B
Discussion
37.

Consider the following reaction at 1000^(@)C(A)Zn(s)+(1)/(2)O_(2)(g)rarrZnO(s),DeltaG^(@)=-360 kJ mol^(-1)(B)C(gr)+(1)/(2)O_(2)(g)rarrCO(g), DeltaG^(@)=-460 kJ mol^(-1).Choose the correct statement At 1000^(@)C

Answer»

ZINC can be oxidized by CARBON monoxide
Zinc oxide can be REDUCED by graphite
Both statements (A) and (B) are TRUE
Both statements (A) and (B) are false

Answer :B
Discussion
38.

Consider the following reaction and the product formed A-CH_(2)-underset(Br)underset(|)CH-CH_(3) underset(C_(2)H_(5)ONa)overset(C_(2)H_(5)OD)rarrA -overset(D)overset(|)C= CH- CH_(3) . One of various product The most likely machanism of the above reaction is

Answer»

`E_(2)`
`E_(1)cb`
`E_(1)`
`E_(2)c`

Solution :Above equilibrium can EXPLAIN the formation of given producthence REACTION must PROCEED by `E1` cb mechanism
.
Discussion
39.

Consider thefollowing reactionat1000^(@)C.A.Zn (s)+(1)/(2) O _ 2 (g) toZn O (s) , Delta G^(@) = -360kJ mol^(-1)B.C (gr)+(1)/(2)O _ 2 (g) toCO (g),Delta G^(@) =-460kJ mol ^(-1) Choosethecorrect statement at1000^(@)C.

Answer»

zinccan beoxidisedby CARBONMONOXIDE.
zincoxide can bereducesbygraphite.
bothstatements(a) and(B)are TRUE.
bothstatements(a)and(b) AREFALSE.

ANSWER :B
Discussion
40.

Consider the following reaction and statements : [Co(NH_(3))_(4)Br_(2)]^(+)+Br^(-)rarr[Co(NH_(3))_(3)Br_(3)]+NH_(3) (I) two isomers are produced if the reactant complex ion is a cis - isomers (II) two isomers are produced if the reactant complex ion is a trans - isomer (III) only one isomer is produced if the reactant complex ion is trans -isomer (IV) only one isomer is produced if the reactant complex ion is a cis - isomer The correct statements are -

Answer»

(III) and (IV)
(II) and (IV)
(I) and (II)
(I) and (III)

SOLUTION :
Discussion
41.

Consider the following reaction and identify the products (AAK_MCP_36_NEET_CHE_E36_022_Q01)

Answer»


(`AAK_MCP_36_NEET_CHE_E36_022_A01`)

ANSWER :B
Discussion
42.

Consider the following reaction and Identify (B)

Answer»




ANSWER :C
Discussion
43.

Consider the following reaction : (A) H^(+)(aq) + OH^(-)(aq) = H_(2)O(l): Delta H = -X_(1) kJ mol^(-1) (B) H_(2)(g) + (1)/(2) O_(2)(g) = H_(2)O(l): Delta H = -X_(2) kJ mol^(-1) ( C ) CO_(2)(g) + H_(2)(g) = CO(g) + H_(2)O(l): Delta H = -X_(3) kJ mol^(-1) (D) C_(2)H_(2)(g) + (5)/(2) O_(2)(g) = 2CO_(2) + H_(2)O(l): Delta H = +X_(4) kJ mol^(-1) Enthalpy of formation of H_(2)O(l) is :

Answer»

`+ X_(1) KJ mol^(-1)`
`- X_(2) kJ mol^(-1)`
`+ X_(3) kJ mol^(-1)`
`- X_(4) kJ mol^(-1)`

Solution :ENTHALPY of FORMATION of `H_(2)O(l)` is
`H_(2)(g) + (1)/(2) O_(2)(g) = H_(2)O(l)`
:. `Delta H = - X_(2) kJ mol^(-1)`
Discussion
44.

Consider the following reaction A + CH_3ONa overset(Delta)to B overset"cold HI"to C_2H_5-OH + CH_3-I. The compound A is

Answer»

`C_2H_5-OH`
`C_2H_5-CHO`
`C_2H_5-Br`
`C_2H_5`

ANSWER :C
Discussion
45.

Consider the following reaction : 8H_(2) (g) + S_(8) (l) rarr 8H_(2) S (g) is carried out at 127^(@) C and 20 atm. Then what mass of S_(8) would be required to produce 8L of H_(2) S (g) under these conditions. [Take : R = 0.08 " atm " L//"mole" - K)

Answer»

1600 gm
1280 gm
20 gm
160 gm

Solution :`8 H_(2) (g) + S_(8) (l) rarr 8H_(2) S (g)`
`T = 400 k`
`P = 20` atm
`V = 8L`
Using `PV = nRT`
`n = 5` mole
For PRODUCING 5 moles of `H_(2)S`,
Moles of `S_(8)` required `= (1)/(8) xx 5 = (5)/(8)` moles
Mass of `S_(8)` required `= (5)/(8) xx (32 xx 8) = 160` gm
Discussion
46.

Consider the following reaction 6NaOH_(("Hot. Conc.")) + 3Cl_2 to 5NaCl + A + 3H_2O. What is the oxidation number of chlorine in "A"?

Answer»

`+5`
`-1`
`+3`
`+4`

ANSWER :C
Discussion
47.

Consider the following reaction 6NaOH+3Cl_(2) rarr 5NaCl+A+3H_(2)O What is the oxidation number of chlorine in A

Answer»

`+5`
`-1`
`+3`
`+1`

Solution :Balance the equation `6NaOH+3Cl_(2) rarr 5NaCl+A+3H_(2)O` to GET, `6NaOH+3Cl rarr 5NaCl+NaClO_(3)+3 H_(2)O`
`:.` A is `NaClO_(3)` where Cl is in +5 OXIDATION state
Discussion
48.

Consider the following reaction 6NaOH + 3Cl_2 overset("Hot conc.")(rarr)5NaCl + A + 2H_2O What is the oxidation number of chlorine in "A"?

Answer»

`+ 5`
`-1`
`+ 3`
`+ 1`

Solution :The product "A " in the REACTION is `NaClO_3` and the oxidation state of Cl in it is + 5.
Discussion
49.

Consider the following reaction, 5H_2O_2+x CIO_2+2OH^(-)toxCI^(-)+yO_2+H_2 O the reactinis balancedif

Answer»

`x=5,y=2`
`x=2 ,y=5`
`x=4 ,y=10`
`x=5,y=5`

Solution :thetwohalfreactionsare ,
oxidation ` H_2 overset(-1)O_2tooverset(0) O_2`
REDUCTION: `overset(+4)CIO_2to CI^(-)`
to balanceO.NinEqn(I ) add`2e^(-)` toR.H.S we have
`H_2O_2to O_2 +2e^(-)`
totalbalancechargeadd`2 OH^(-)to O_2 + 2e^-`
tobalanceH and O atoms add2 `H_2O`to the R.H.Swehave
` H_2O_2+ 2OH^(- )to O_2+2H_2 O + 2e^(-)`
thisis theoxidationhalfequation
tobalanceO.Nin EQN(ii ) add`5e^(-)`to L.H.Swe have
`CIO_2+ 5E^( -)to CI^(-)`
to balancechangeadd4 `OH^(- ) ` to theR.H.Swe have
`CIO_2+ 5e^(- )to CI+ 4 OH`
to balanceO ANDH atomsAdd2 `H_2O` toL.H.Swe have`CIO_2+ 2 H_2O+ 5 e^(- )to CI^( -)+ 4 OH^(-)`
thisis thebalanced reductionhalfequation
tocancel the numberof electronslostin eqn(v )andgainedin Eqn(viii )multiplyEqn(v )by5 and Eqn(viii )by2and addwe have

thusx thecoefficientof `CIO_2 `is 2whiley thecoefficientof` CI^(-)`is 5
Discussion
50.

Consider the following reactions : 2XS+3O_(2)overset(Delta)to 2XO+2SO_(2) 2XO+XS overset(Delta)to 3' X'+SO_(2) Then 'X' can not be :

Answer»

`Hg`
`Pb`
`ZN`
`CU`

ANSWER :B
Discussion