Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

2301.

When 4g of iron is burnt to ferric oxide at constant pressure, 29.28KJ of heat is evolved. What is the enthalpy of formation of ferric oxide (At wt. of Fe=56)

Answer»

`-81.98 kJ`
`-819.8 kJ`
`-40.99 kJ`
`+819.8 kJ`

SOLUTION :Given: Weight of iron burnt=4g, Heat liberated =29.28 KJ and ATOMIC weight of iron (Fe)56. We know that in ferric OXIDE `(Fe_(2)O_(3))`, 2 moles of iron or `2xx56=112`gram of iron are burnt. We also know that when 4 grams of iron are burnt, then heat liberated = 29.28 kJ, therefore when 112 grams of the iron are burnt, then heat liberated `=(29.28xx112)/(4)=-819.8 kJ`(Minus sign due to LIBERATION of heat).
Discussion
2302.

Which of the following compounds are coloureddue to change transfer spectrun ?

Answer»

`K_(2)Cr_(2)O_(7)`
`KMnO_(4)`
`MnSO_(4)`
`MnO_(2)`

Answer :A::B
Discussion
2303.

What will be the pH of a solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M NaOH

Answer»

12
10
8
6

Solution :M.eq. of 0.01 M HCL `= (0.10)/(1000) xx 40 = 0.004 M`
M.eq. of 0.45 M NAOH `= (0.45 xx 10)/(1000) = 0.0045 M`
Now left `[OH^(-)] = 0.0045 - 0.004 = 5 xx 10^(-4)M`
Total volume = 50 ml
`[OH^(-)] = (5 xx 10^(-4))/(50) xx 1000, [OH^(-)] = 1 xx 10^(-2)`
`pOH = 2, pH = 14 - pOH = 12`.
Discussion
2304.

Two moles of a gas at 1 bar and 298 K are compressed at constant Temperature by use of a constant pressure of 5 bar. How much work is done on the gas ? If the compression is driven by a 100-kg mass, how far will it fall in the earth's gravitational field ? (g=9.8 ms^(-2))

Answer»

Solution :We have, for an irreversible ISOTHERMAL process,
`W=-p_(2)(V_(2)-V_(1))` …(Eqn. 2)
`=-p_(2)((nRT)/(p_(2))-(nRT)/(p_(1)))`
`=nRT(1-(p_(2))/(p_(1)))`
`-2xx8.314xx298 (1-(5)/(1))`
`=19820 J`.
Further, W=mgh …(Eqn. 3b)
`H=(W)/(mg)=(19820)/(100xx9.8)m`
`=20.22` m.
The following problems are based on THERMOCHEMICAL CALCULATIONS. In dealing with these problems, we apply the INSPECTION method, as discussed previously.
Discussion
2305.

The vapour pressure of solution and pure solvent P and P_(0) resp. If P/P_(0) is 0.15. Then the mole fraction of the solute in the solution is

Answer»

<P>0.85
0.15
`1//0.15`
`1//0.85`

SOLUTION :`X_(2)=(P_(1)^(0)-P)/(P_(1)^(0))`
`= 1-P_(X)/P_(1)^(0)=1-0.15=0.85`
Discussion
2306.

Which is an aromatic alcohol :

Answer»

`CH_2=CHCH_2OH`
`CH_2OHCH_2OH`
`C_6H_5CH_2OH`
`C_6H_5OH`

ANSWER :D
Discussion
2307.

Which one is not a step polymer?

Answer»

NYLON`6,6`
Nylon-`6`
GLYPTAL
`PMMA`

ANSWER :D
Discussion
2308.

Which of the following is strong acid ?

Answer»

`CF_(3)COOH`
`C Cl_(3) COOH`
`CBr_(3) COOH`
`CI_(3) COOH`

Answer :A
Discussion
2309.

Which is the possible oxidation states of phosphoraus in its compounds ?

Answer»

`-3` to `+5`
`-3, +3` to `+5`
`-3, 0, +5`
0 to `+5`

ANSWER :A
Discussion
2310.

When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and the solution turns blue. {:([Co(H_(2)O)_(6)]^(3+)(aq)+4Cl^(-)(aq) to [CoCl_(4)]^(2-)(aq)+6H_(2)O(l)),("pink""blue"):} However when cooled to a temperature below room tempertaure, the solution turns pink . On the basis of this information mark the appropriate option :

Answer»

`DeltaH=0` for the REACTION
`DeltaHgt0` for the reaction
`DELTAHLT0` for the reaction
`DeltaH` can not be concluded

Solution :`DeltaH gt 0`, b/c on decreasing the temp. `RX^(N)` GOES backward.
Discussion
2311.

Write the name of an antacid which is often used.

Answer»

SOLUTION :The ANTACID COMMONLY USED is RANITIDINE (Zintac).
Discussion
2312.

Which one of the following methods is used to prepare Me_(3)COEt with a good yield

Answer»

Mixing EtONa with `Me_(3)C CL`
Mixing `Me_(3)CONa` with EtCl
heating a mixture of (1:1) EtOH and `Me_(3)COH` in presence of conc. `H_(2)SO_(4)`
Treatment of `Me_(3)COH` withh EtMgI

Solution :`CH_(3)-underset(CH_(3))underset(|)OVERSET(CH_(3))overset(|)(C)-OVERLINE(O)Naoverset(+)(a)+CH_(3)CH_(2)Cl overset(S_(N^(2))toCH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C)-O-CH_(2)CH_(3)+NaCl`
Williamson's synthesis `(S_(N^(2)))` given by `1^(@)` ALKYL halides.
Discussion
2313.

Which of the following has lowest reducing character?

Answer»

`H_(2)O`
`H_(2)S`
`H_(2)TE`
`H_(2)SE`.

ANSWER :A
Discussion
2314.

Which among the following on dehalogenation will give trans-alkene ?

Answer»




ANSWER :A
Discussion
2315.

Which of the following reaction is not representing major product.

Answer»



`Ph-overset(O)overset(||)(C )-NH_(2)overset(Br_(2))underset(KOH)rarrPh-NH_(2)`

Solution :(A) `CH_(3)` is not attached with benzene RING in REACTANT milecule.
Benzene ring is anti to -Cl, which will migrates and give the as a major product (Friscth REACTION)
Haffmann broamamide reation
Discussion
2316.

Those elements impart colour to the flame on heating in it, the atoms of which require low energy for the ionisation (i.e. absorb energy in the visible region of spectrum). The elements of which of the following groups in Modern periodic table will impart colour to the flame?

Answer»

2
13
1
17

Solution :Elements of Group 1 & 2 have low `IE` have. So they impart COLOUR to FLAME. `E.g. LI, Na, K, Ca, Ba`, etc.
Discussion
2317.

What is/are the coordination number(s) of Au in the complexes formed by Au ?

Answer»

6
4
5
2

Solution :GENERALLY, gold exposed a primary valency of 4 in its complex compounds. EG. `[AuCl_(4)]^(-)`.
Discussion
2318.

Write the name (IUPAC norm) and draw the possible optical isomers of [CrCl_(2)(en)(NH_(3))_(2)]^(+).

Answer»

Solution :IUPAC NAME of the compound is :
Diamminedichlorido( ethane-1, 2- DIAMINE )diamminechromium(III)
Optical isomers of the complex are GIVEN below :
Discussion
2319.

Which of the following is hydrophobic sol?

Answer»

Starch
Gum
Gelatin
Protein.

ANSWER :D
Discussion
2320.

What can be accurately predicted for the isomerization reaction between gaseous penta-1,4-diene and gaseous penta-1.3-diene?

Answer»

The PROCESS is EXOTHERMIC
ENTHALPY change of the reaction is same as resonance energy of the product
Magnitude of enthalpy of combustion of product is more than that of the REACTANT
Combustion of the reactant will be exothermic while the same for the products will BC endothermic.

Answer :A
Discussion
2321.

Two volatile and miscible liquids can be separated by fractional distillations into pure components under the condition into pure components under the condition

Answer»

They have low BOILING points
The differencein boiling POINT is large
The boiling of two liquids are close to each other
They do not FORM axeotropic mixture

ANSWER :C
Discussion
2322.

Write two uses of ClO_2 .

Answer»

Solution :(i) It is an EXCELLENT bleaching agent. Its bleaching power is about 30 times higher than that of `Cl_2`. It is used for bleaching FLOUR to make white bread.
(ii) `ClO_2` is a POWERFUL OXIDISING agent and chlorinating agent. Large QUANTITIES of `ClO_2` are used for bleaching wood pulp and cellulose and for purifying drinking water.
Discussion
2323.

Which among the following gives1^(@) amine on reduction?

Answer»

`CH_(3)-CH_(2)NO_(2)`
`CH_(3)CH_(2)-O-N=O`
`C_(6)H_(5)-N=NC_(6)H_(5)`
`CH_(3)CH_(2)NC`

Answer :1
Discussion
2324.

Three moles of PCl_(5) , three moles of PCl_(3) and two moles of Cl_(2) are taken in a closed vessel . If at equilibrium the vessel has 1.5 moles ofPCl_(5) , thenumber of moles of PCl_(3) present in it is

Answer»

6
4.5
5
3

Solution :`{:(PCl_(s(G))hArrPCl_(3(g))_Cl_(2(g))),("332(Initially)"),((3-x)""(3+x)""(2+2)" (At equilibrium)"):}`
Given that `(3-x)=1.5thereforex=1.5`
THEREFORE no. of moles of`PCl_(3(g))`present is
`=3+1.5=4.5`
Discussion
2325.

The statement which is incorrect withrespect to glucose is

Answer»

Reduces Felhing's SOLUTION and TOLLEN's reagent
Reacts with hydroxylamine to form an oxime
Adds a MOLECULE of hydrogen CYANIDE to GIVE cyanohydrin
Gives yellow ppt with I2 in alkali

Answer :D
Discussion
2326.

Which of the following types of drugs reduces fever?

Answer»

Analgesic
Antipyretic
Antibiotic
Tranquilizers.

Answer :B
Discussion
2327.

X will be

Answer»




none

Answer :C
Discussion
2328.

The second ionisation energies are higher than the first ionisation energies. This is mainly due to the fact the after the removal of the first electron, the atom changes into monovalent positive ion. In the ion, the number of electrons decreases but the nuclear charge remains the same. as a result of this, the remaining electrons are held more tightly by the nucleus and it becomes difficult to remove the second electron. therefore, the value of second ionisation energy. (IE_(2)), is greater than that of the first ionisatio energy (IE_(1)). similarly third ionisation energy (IE_(3)) is greater than that of second IE_(2). Q. Successive ionisation energy of an atom is greater than previous one, because:

Answer»

`p/e` RATIO increases
`p/e` ratio decreases
`p/e` ratio REMAINS constant
none of these

Answer :A
Discussion
2329.

Which acid of each pair shown here would you expect to be stronger? (i) CH_3CO_2H or CH_2FCO_2H (ii) CH_2FCO_2H or CH_2ClCO_2H (iii) CH_2FCH_2CH_2CO_2H or CH_3CHFCH_2CO_2H (iv)

Answer»

Solution :(i) `FCH_2CO_2H` is stronger than `CH_3CO_2H` DUE to - I - effect and stablisation of the carboxylate ion of `FCH_2CO_2H` as shown below:

(ii) Due to much stronger I-effect of F than Cl, the `FCH_3COO^(-)` ion is much more stable than `ClCH_2COO^(-)` ion. Protons are released in greater CONCENTRATION in `FCH_2COOH`. Hence, `FCH_2COOH` is a stronger acid than `ClCH_2COOH`.
(iii)
Inductive effect decreases with distance , therefore, -I-effect of F is a stronger in 3-fluorobutanoic acid than in 4-fluorobutanoic acid. Hence, `CH_3CHICH_2COOH` is a stronger acid than `FCH_2CH_2CH_2COOH`.
(iv)
Therefore due to greater STABILITY of `F_3C - C_6H_4 - COO^(-)` (p) ion over `CH_3 - C_6H_4COO^(-)` (p) ion, `p - F_3C - C_6H_4-COOH` is a much stronger acid than `p - CH_3-C_6H_4 - COOH`.
Discussion
2330.

The second ionisation energies are higher than the first ionisation energies. This is mainly due to the fact the after the removal of the first electron, the atom changes into monovalent positive ion. In the ion, the number of electrons decreases but the nuclear charge remains the same. as a result of this, the remaining electrons are held more tightly by the nucleus and it becomes difficult to remove the second electron. therefore, the value of second ionisation energy. (IE_(2)), is greater than that of the first ionisatio energy (IE_(1)). similarly third ionisation energy (IE_(3)) is greater than that of second IE_(2). Q. Correct order of ionisation potential of coinage metals is:

Answer»

`AU gt AG gt CU`
`Cu gt Ag gt Au`
`Au gt Cu gt Ag`
`Ag gt Cu gt Au`

ANSWER :C
Discussion
2331.

The second ionisation energies are higher than the first ionisation energies. This is mainly due to the fact the after the removal of the first electron, the atom changes into monovalent positive ion. In the ion, the number of electrons decreases but the nuclear charge remains the same. as a result of this, the remaining electrons are held more tightly by the nucleus and it becomes difficult to remove the second electron. therefore, the value of second ionisation energy. (IE_(2)), is greater than that of the first ionisatio energy (IE_(1)). similarly third ionisation energy (IE_(3)) is greater than that of second IE_(2). Q. IE_(1) and IE_(2) of Mg metal are 178 and 348 kcal/mol respectively. the energy required for the given reaction is: Mg(s) to Mg^(+2)+2e^(-)

Answer»

`+170` kcal/mol
`+526` kcal/mol
`-170` kcal/mol
`-526` kcal/mol

Answer :B
Discussion
2332.

Write IUPAC name of (i) K_(3)[Ag(S_(2)O_(3))_(2)] (ii) [Fe(H_(2)O)_(4)(C_(2)O_(4))_(2)]SO_(4)

Answer»

SOLUTION :(i) POTASSIUM dithiosulphatoargentate (I) (II) tetraaquadioxalatoiron (II) SULPHATE
Discussion
2333.

Which one is most basic in character:

Answer»

`F^-`<BR>`CL^-`
`Br^-`
`I^-`

ANSWER :A
Discussion
2334.

Which one of the following is the correct order of relative reactivities of alcohols in the dehydration reaction?

Answer»

`1^(@) LT 2^(@) lt 3^(@)`
`2^(@) lt 1^(@) lt 3^(@)`
`3^(@) lt 2^(@) lt 1^(@)`
`3^(@) lt 1^(@) lt 2^(@)`

SOLUTION :`1^(@) lt 2^(@) lt 3^(@)`
Discussion
2335.

Which of the following would undergo Hoffmann reaction to give a primary amine ?

Answer»

`R-overset(O)overset("||")(C )-CL`
`RCONHCH_(3)`
`RCONH_(2)`
RCOOR

SOLUTION :When a primary amide is heated with an aqueous solution of KOH and `Br_(2)`, it gives a primary amine with one carbon atom less.
`RCONH_(2)+Br_(2)+4KOH overset(Delta)rarr RNH_(2)+2KBr+K_(2)CO_(3)+2H_(2)O`
This is known as Hoffmann DEGRADATION reaction.
Discussion
2336.

Which of the following represents the most oxidized form of hydrocarbon

Answer»

`CO_2`
RCHO
RCOOH
RCOOOH

Solution :HYDROCARBONS ONE complete oxidation PRODUCED `CO_2` and water
`CH_3-CH_3+3 1/2O_2 to 2CO_2 + 3H_2O`
Discussion
2337.

Which of the following is biodegradable polymer ?

Answer»

Nylon-6
Nylon-2-nylon-6
Terylene
Nylon-6,6

Answer :B
Discussion
2338.

Write the structural formula of 1 - phenylpental -1- one.

Answer»

Solution :`CH_(3)-CH_(2)-CH_(2)-CH_(2)-UNDERSET(C_(6)H_(5))underset("|")"C "=O`
Discussion
2339.

What is the major product of the following reaction ?

Answer»

SOLUTION :
The MAJOR PRODUCT of the REACTION is BENZAMIDE.
Discussion
2340.

The standard reduction potential for the Zn^(2+) (aq)//Zn (s) half cell is - 0.76V. Write the reactions occurring at the electrodes when coupled with standard hydrogen electrode (SHE).

Answer»

SOLUTION :`{:("At anode:",Zn(s)RARRZN^(2+)(AQ)+2E^(-)),("At CATHODE:",2H^(+)+2e^(-)rarrH_(2)(g)):}`
`Zn(s)+2H^(+)(al)rarrZn^(2+)(aq)+H_(2)(g)`
Discussion
2341.

Which is true for solution with the same osmotic pressure at the same temperature ? (M is molar mass)

Answer»

`C_(1)=C_(2)`
`M_(1)=M_(2)`
`C_(1)M_(1)=C_(2)M_(2)`
`C_(1)//M_(1)=C_(2)//M_(2)`

ANSWER :A
Discussion
2342.

Zn cannot displace ____ ion from the aqueous solution:

Answer»

`AG^+`
`CU^(2+)`
`FE^(2+)`
`Na^+`

Answer :D
Discussion
2343.

What is the product formed when acetylene dissolved in ethyl alcohol combines with chlorine ?

Answer»

SOLUTION :ACETYLENE TETRACHLORIDE or WESTRON Is FORMED.
Discussion
2344.

The tendency of the transition metals to form complexes is not explained by:

Answer»

Small SIZE of the metal ion
Large IONIC or NUCLEAR charge
Low BASICITY of metal ions
Non-availability ofd-orbitals

Answer :D
Discussion
2345.

What are the coordination number of Na^(+) and Cl^(-) ions in NaCl?

Answer»

SOLUTION :`NA^(+) = 6, CL^(-) = 6`
Discussion
2346.

Three elements Na S and O combine to form a compund Na_(2_SO_(3) what is the valency of S in this compund ?

Answer»

`H_(2)SO_(4)gtH_(3)PO_(3)gtCH_(3)COOH`
`H_(3)PO_(3)gtH_(2)SO_(4)gtCH_(3)COOH`
`CH_(3)COOHgtH_(3)PO_(3)gtH_(2)SO_(4)`
`CH_(3)COOHgtH_(23)SO_(4)gtH_(3)PO_(3)`

Solution :`H_(2)SO_(4)gtH_(3)PO_(3)gtCH_(3)COOH`
Discussion
2347.

The work done during the expansion of a gas from a volume of 4dm^(3)" to "6 dm^(3) against a constant external pressure of 3 atm is (1 L atm = 101.32 J)

Answer»

`-6J`
`-608J`
`+304J`
`-304` (J)

ANSWER :B
Discussion
2348.

Which represents a chelating ligand:

Answer»

`CL^-`
DMG
`OH^-`
`H_2O`

ANSWER :B
Discussion
2349.

The thermal decomposition of HCO_(2)H is a first order reaction with a rate constant of 2.4xx10^(-3)s^(-1) at a certain temperature. Calculate how long will it take for three-fourths of initial quantity of HCO_(2)H to decompose (log0.25=-0.6021).

Answer»


SOLUTION :`x=(3)/(4)a,t=(2.303)/(k)LOG""(a)/(a-3//4a)=(2.303)/(2.4xx10^(-3))log4s=(2.303)/(2.4xx10^(-3))(0.6021)s=9" MIN "38" s"`
or `t_(1//2)=(0.693)/(k)=(0.693)/(24xx10^(-3))s=288.75s,t_(3//4)=2xxt_(1//2)`
Discussion
2350.

Which compound has the highest boiling point

Answer»

Acetone
Diethyl ETHER
Methanol
Ethanol

SOLUTION :DUE to HYDROGEN BONDING
Discussion