Grass-G/jee-main-questions huggingface dataset:
Subject: Chemistry — Physical Chemistry — Chemical Equilibrium
Difficulty: Moderate

Question: In an experiment starting with 1 mole of ethyl alcohol, 1 mole
of acetic acid and 1 mole of water at TºC, the equilibrium mixture on
analysis shows that 54.3 of the acid is esterfied. Calculate the
equilibrium constant of this reaction.


Answer: 4.0

Solution:
${CH}_{3}COOH(I) + C_{2}H_{5}OH(l) \rightleftharpoons {CH}_{3}{COOC}_{2}H_{5}(l) + H_{2}O(l)$
Initial 1 1 0 1
At equilibrium 1 - x 1 - x x 1 + x
1 - 0.543 1 - 0.543 0.543 1 + 0.543
$\left( 54.3\%\ of\ 1mole = \frac{1 \times 54.3}{100} = 0.543mole \right)$
Hence given x = 0.543 mole
Applying law of mass action
$K_{C} = \frac{\lbrack\ ester\ \rbrack\lbrack\ water\ \rbrack}{\lbrack\ acid\ \rbrack\lbrack\ alcohol\ \rbrack} = \frac{0.543 \times 1.543}{0.457 \times 0.457} = 4.0$
Subject: Chemistry — Organic Chemistry — Organic Chemistry
Difficulty: Easy

Question: A solution of [IMAGE] -chloro-2-phenylethane in
toluene racemizes slowly in the presence of small amount of
[IMAGE] due to the formation of

1) Carbanion
2) Carbene
3) Free radical
4) Carbocation

Correct option: 4

Solution:
Subject: Chemistry —  — 

Question: Which of the following metal salt gives chromyl chloride test?

4) KCI


Solution:
This is a chemical test to detect chloride ion in the qualitative
analysis. Any chloride when heated with edified potassium dichromate
orange, red fumes of chromyl chloride are released. This confirms
presence of chloride.
Subject: Chemistry —  — 

Question: [IMAGE] In the above reaction,[IMAGE] acts as

1) oxidising agent
2) indicator
3) reducing agent
4) catalyst


Solution:
Oxidation number of sulphur in [IMAGE] is
increasing so reacting as reducing agent
Subject: Chemistry — Physical Chemistry — Some Basic Concepts of Chemistry
Difficulty: Moderate

Question: Number of moles of CaO required to remove hardness from 1000
litre water having 324 ppm of calcium bicarbonate is



Solution:
Ca(HCO_3)_2 +
$\frac{324}{162}$ = n_CaO = 2
Subject: Chemistry — Physical Chemistry — Chemical Equilibrium
Difficulty: Moderate

Question: The exothermic formation of ClF3 is represented by the equation:
Cl2 (g) + 3F2 (g) [IMAGE] 2ClF3 (g); ΔrH = - 329 J
which of the following will increase the quantity of CIF3 in an
equilibrium mixture of Cl2, F2 and ClF3.

1) Adding F2
2) Increasing the volume of container
3) Removing Cl2
4) Increasing the temperature
ClF_3 dh Cl2 (g) + 3F2 (g) [IMAGE] 2ClF3 (g); ΔrH = - 329 J

Correct option: 1

Solution:
CI2 (g) + 3F2 (g)[IMAGE] 2CIF3 (g); DH = - 329
kJ. Favourable conditions:
(i) Decrease in temperature, (ii) Addition of reactants, (iii)
Increase in pressure i.e., decrease in volume.
CI2 (g) + 3F2 (g)[IMAGE] 2CIF3 (g); DH = - 329 kJ.
vuqdqy ifjfLFkfrA
(i) (ii) (iii) nkc
Subject: Chemistry —  — BCC& Density
Difficulty: Easy

Question: Chromium metal crystallizes with a body centered cubic lattice.
The length of the unit cell is found to be 287 pm. Calculate the atomic
radius. What would be the density of chromium in g/cm3?


Answer: 124.27

Solution:
We know for B.C.C. $4R = a\sqrt{3}$
$R = \frac{287 \times \sqrt{3}}{4} = 124.27pm$
Density
$= \frac{2 \times 52}{6.023 \times 10^{23}{(287 \times 10^{- 10})}^{3}} = 7.30gm/{cm}^{3}$
Subject: Chemistry — Physical Chemistry — 
Difficulty: Moderate

Question: 6.02 × 1020 molecules of urea are present in 100 ml of its
solution. The concentration of urea solution is:
lkUnzrk


Answer: 0.01

Solution:
Moles of urea 
$= \frac{6.02 \times 10^{20}}{6.02 \times 10^{23}} = 10^{- 3}moles$
Concentration (molarity) of solution ¼eksyjrk½
$= \frac{10^{- 3}}{100} \times 1000 = 0.01M$
Subject: Chemistry — IUPAC and Structural Isomerism — 
Difficulty: Easy

Question: The total number of cyclic isomers possible for a hydrocarbon
with the molecular formula C4H6 is / are


Answer: 5

Solution:
The DU of C4H6 =
Subject: Chemistry — Organic Chemistry — Alcohools,Ether and Phenol
Difficulty: Tough

Question: Consider the reaction sequence below:
[IMAGE] x is


Correct option: 4

Solution:
The complete sequence of reaction is given below.
Subject: Chemistry — Organic Chemistry — Chemistry in everyday life
Difficulty: Easy

Question: Which of the following is not used in rocket propellants

1) $H_{2}(l)$
2) $O_{2}(l)$
3) $N_{2}H_{4}(l)$
4) All of these

Correct option: 4

Solution:
All are fuel.
Subject: Chemistry — Inorganic Chemistry — Periodic table
Difficulty: Moderate

Question: [IMAGE] Where a, b, c, d, e, f, g, h are 3rd period elements. If difference
between atomic number of elements b and e is x and difference between
atomic number of elements c and f is y. What is the value of x - y.

1) 0.1
2) 0
3) 1.0
4) 01

Correct option: 2

Solution:
a is Na, b is Mg, c is Al, d is Si, e is P, f is S, g is Cl, h
is Ar,
x = 3, y = 3
x - y = 0
Subject: Chemistry — Physical Chemistry — Thermodynamics
Difficulty: Easy

Question: At constant T and P. which one of the following statements is
correct for the reaction, [IMAGE].

1) [IMAGE] is independent of the physical state of the
reactants of that compound

Correct option: 3

Solution:
Subject: Chemistry — Ideal Gas — Ideal gas equation & gas laws
Difficulty: Easy

Question: Pressure of the gas in column

1) is
2) 55 cm of Hg
3) 50 cm of Hg
4) 45 cm of Hg

Correct option: 1

Solution:
$P_{g = 1} = 75 - \frac{101}{2} - \frac{20 \times 6.8}{13.6} \times \frac{1}{2} = 60cm\ of\ Hg$
Subject: Chemistry — Atomic Structure — Bohr Model
Difficulty: Tough

Question: Consider Bohr's theory for hydrogen atom. The magnitude of
angular momentum, orbit radius and velocity of the electron in
n^thenergy state in a hydrogen atom are, r & v respectively. Find out
the value of if product of v, r and l (vrl) is directly
proportional to nx.
gkbMªkstu ijek.kq ds fy, cksj fl)kUr dks ekurs gq, gkbMªkstu ijek.kq
ds nth voLFkk o
bysDVªkWu osx rks, dk eku Kkr djks;fn v,
r rFkk  rhuksa


Answer: 2

Solution:
Angular momentum, $\mathcal{l} = mvr = \frac{nh}{2\pi}$
$\therefore\mathcal{l}\infty\ n$
Radius, $r = 0.529\frac{n^{2}}{z}A^{0}$ $\therefore r\ \infty n^{2}$ For
same Z
Velocity, $v = 2.18 \times 10^{6}\frac{z}{n}m/s$
$\therefore v\infty\frac{1}{n}$
$\therefore vr\mathcal{l}\infty n \times n^{2} \times \frac{1}{n}$
But, v r l µ nx (given)
$\therefore n^{2} = n^{x}$
$\therefore x = 2$
$\therefore\mathcal{l}\ \infty\ n$
$r = 0.529\frac{n^{2}}{z}A^{0}$ $\therefore r\ \infty\ n^{2}$ leku Z ds
fy,
$\therefore v\ \infty\ \frac{1}{n}$
$\therefore vr\mathcal{l}\infty n \times n^{2} \times \frac{1}{n}$
ijUrq] v r  ∝ nx (¼ ½
$\therefore n^{2} = n^{x}$
$\therefore x = 2$
Subject: Chemistry — IUPAC Nomenclature and Structural Isomerism — Number of Structural Isomers
Difficulty: Moderate

Question: Draw all structurally isomeric benzene containing isomers with
molecular formula [IMAGE]


Answer: 5

Solution:
Subject: Chemistry — Inorganic Chemistry — Metallurgy
Difficulty: Moderate

Question: Complex is formed in the extraction of

1) Na
2) Cu
3) Ag
4) Fe

Correct option: 3

Solution:
Hydrometallurgy
Ag_2 S + 4NaCN → 2Na[Ag(CN)_2 ] + Na_2 S
Subject: Chemistry — Organic Chemistry — Organic Chemistry
Difficulty: Tough

Question: The electrophile in the nitration of benzene is


Correct option: 1

Solution:
[IMAGE] is produced when conc.
[IMAGE] reacts with conc. [IMAGE].
Subject: Chemistry —  — Simple Cubic Structure & BCC
Difficulty: Easy

Question: Iron has body centerd cubic lattice structure. The edge length of
the unit cell is found to be 286 pm. What is the radius of an iron atom?

1) r = 124 pm
2) r = 128 pm
3) r = 124
4) r = 128

Correct option: 1

Solution:
For bcc structure
$\sqrt{3}a = 4r,r = \frac{\sqrt{3}a}{4} = \frac{1.732 \times 286}{4} = 123.8 \approx 124pm$
Subject: Chemistry — Chemical Bonding — Octet rule, Lewis dot structures
Difficulty: Moderate

Question: The possible structure of monothiocarbonate ion is


Correct option: 4

Solution:
The monothiocarbonate is CSO22- and carbon cannot have more
than 8 electrons in its valence shell.
Subject: Chemistry — Physical Chemistry — Gaseous state
Difficulty: Moderate

Question: Two separate bulbs contain ideal gases A and B. The density of
gas A is twice that of gas B. The molecular mass of A is half that of
gas B. The two gases are at the same temperature. The ratio of the
pressure of A to that of gas B is

1) 2
3) 4

Correct option: 3

Solution:
$d_{a} = 2d_{b};2M_{a} = M_{b}$
$PV = nRT = \frac{m}{M}RT;P = \frac{m}{V} \cdot \frac{RT}{M} = \frac{dRT}{M}$
$\frac{P_{a}}{P_{b}} = \frac{d_{a}}{d_{b}}\frac{M_{b}}{M_{a}} = \frac{2d_{b}}{d_{b}} \times \frac{2M_{a}}{M_{a}} = 4$
Subject: Chemistry — Carbonyl Compound (Aldehyde and Ketone) — Cannizzaro's reactions
Difficulty: Tough

Question: In the reaction
${({CH}_{3})}_{3}CCHO + HCHO\frac{NaOH}{heat}A + B$the products (A) and
(B) are respectively

1) ${({CH}_{3})}_{3}{CCH}_{2}OH\ and{\ HCOO}^{-}{Na}^{+}$
2) ${({CH}_{3})}_{3}CCOON\ aand{\ CH}_{3}OH$
3) ${({CH}_{3})}_{3}{CCH}_{2}OH\ and\ {CH}_{3}OH$
4) ${({CH}_{3})}_{3}COONa\ and\ {HCOO}^{-}{Na}^{+}$

Correct option: 1

Solution:
Subject: Chemistry — Chemical Kinetics — Integrated Rate law : Second Order & Pseudo first order
Difficulty: Moderate

Question: A reaction, which is second order, has a rate constant of
[IMAGE]. If the initial conc. of the reactant is 0.2 M.
how long will it take for the concentration to become 0.0400 M?

1) 1000 sec
2) 400 sec
3) 200 sec
4) 10,000 sec

Correct option: 4

Solution:
Subject: Chemistry — Physical Chemistry — Periodic Table
Difficulty: Easy

Question: In the given, how many atoms have greater first ionisation energies
than Boron ?
 ?
Li Be C N O F He


Answer: 06

Solution:
Subject: Chemistry — Organic Chemistry — Stereoisomerism
Difficulty: Moderate

Question: The total number of cyclic structural as well as stereo isomers
possible for a compound with the molecular formula C5H10 is


Answer: 7

Solution:
Subject: Chemistry — Physical Chemistry — Atomic Structure
Difficulty: Moderate

Question: A particle X moving with certain velocity has a de-Broglie
wavelength of 1Aº. If particle and
velocity 75 that of will be

1) 0.19 Aº
2) 5.33 Aº
3) 6.88 Aº
4) 4.8 Aº

Correct option: 2

Solution:
$\frac{\lambda_{x}}{\lambda_{Y}} = \left\lbrack \frac{m_{Y}}{m_{x}} \right\rbrack \cdot \left\lbrack \frac{V_{Y}}{V_{x}} \right\rbrack$
= 2.25 × 0.75 = $\frac{3}{16};\lambda_{Y} = \frac{16}{3}\lambda_{x}$ =
5.33 Aº
Subject: Chemistry — Mole concept — Principle of atom conservation (POAC), Reactions in sequence
Difficulty: Tough

Question: What weights of P4O6 and P4O10 will be produced by the
combustion of 31g of P4 in 32g of oxygen leaving no P4 and O2.

1) 2.75 g, 219.5 g
2) 27.5 g, 35.5 g
3) 55 g, 71 g
4) 17.5 g, 190.5 g

Correct option: 2

Solution:
P4 + O2 → P4O6 + P4O10
31 gram 32 gram
According to question weight of P is conserved so
Let Mole of P4O6 = a
Mole of P4O10 = b
Initial weight of P = Final weight of P.
31 = × 31 + × 31
4 a + 4b = 1] (1) × 3
Initial weight of oxygen = Final weight of oxygen
32 = × 16 + × 16
3a + 5b = 1] (2) × 4
12 a + 20 b = 4
12 a + 12 b = 3 So $b = \frac{1}{8}$
8 b = 1
Similarly $a = \frac{1}{8}$
So weight of
$P_{4}O_{6} = \frac{1}{8} \times 220 = 27.5P_{4}O_{10} = \frac{284}{8} = 35.5$
Subject: Chemistry — Inorganic Chemistry — p-block elements
Difficulty: Moderate

Question: Total number of lone pair of electrons in XeOF_4 is


Answer: 1

Solution:
Therefore, total number of lone pair of electron on central
atom Xenon =1
Subject: Chemistry — Inorganic Chemistry — Environmental Chemistry
Difficulty: Moderate

Question: Particulates matter contains ______

1) Chlorobenzene
2) Toluene
3) Nitrobenzene
4) Polycyclic hydrocarbons

Correct option: 4

Solution:
Explanation: Polycyclic aromatic hydrocarbons (PAHs) are two or
more fused aromatic rings containing compounds, form by various
anthropogenic processes and present in both particulate and gaseous
phases.
Subject: Chemistry — Physical Chemistry — Thermodynamics
Difficulty: Moderate

Question: The enthalpy change for the transition of liquid water to steam.
[IMAGE]. The entropy change for the process is


Correct option: 3

Solution:
Subject: Chemistry — Atomic Structure — Bohr Model
Difficulty: Moderate

Question: Which is the correct relationship?

1) E1 of H = E3 of Li2+ = 1/4 E4 of Be3+
2) E1(H) = E2(He+) = E3 (Li2+) = E4(Be3+)
3) E1(H) = 2E2(He+) = 3E3 (Li2+) = 4E4(Be3+)
4) No relation

Correct option: 2

Solution:
$E_{1}(H) = - 13.6 \times \frac{1^{2}}{1^{2}} = - 13.6eV$
$E_{2}({He}^{+}) = - 13.6 \times \frac{2^{2}}{2^{2}} = - 13.6eV$
$E_{3}({Li}^{2 +}) = - 13.6 \times \frac{3^{2}}{3^{2}} = - 13.6eV$
$E_{4}({Be}^{3 +}) = - 13.6 \times \frac{4^{2}}{4^{2}} = - 13.6eV$
$\therefore E_{1}(H) = E_{2}({He}^{+}) = E_{3}({Li}^{2 +}) = E_{4}({Be}^{3 +})$
Subject: Chemistry — Organic Chemistry — Hydrocarbon
Difficulty: Moderate

Question: Which of the following compound is not suitable to obtain from
wurtz reaction?

1) ethane
2) butane
3) isobutane
4) hexane
mi;qDr ugha

Correct option: 3

Solution:
Wurtz reaction is not suitable for the preparation of isobutane
because two different alkylhalides are used for the preparation of
isobutane so, mixture of three different compounds are produced which is
very difficult to separate in pure form.
Wurtz reaction fy, rhu vyx&vyx feJ.k mRiUu gksrk gS tks "kq):i
Subject: Chemistry — Physical Chemistry — Ionic Equilibrium
Difficulty: Moderate

Question: For a solution obtained by mixing equal volumes of 0.02 M KOH
solution & 0.2 M B (weak diacidic base; = 10^-7 &
[IMAGE] = 10^-14) solution

1) pH = 12
2) [BH^+] = 10^-6 M
3) $\left\lbrack {BH}_{2}^{2 +} \right\rbrack = 10^{- 18}M$
4) All of these

Correct option: 4

Solution:
$\left\lbrack {OH}^{-} \right\rbrack = \frac{0.02}{2} = 0.01M\therefore pH = 12$
$10^{- 7} = \frac{0.01\left\lbrack {BH}^{+} \right\rbrack}{0.1} \Rightarrow \left\lbrack {BH}^{+} \right\rbrack = 10^{- 6}M$
$10^{- 7} \times 10^{- 14} = \frac{(0.01)^{2}\left\lbrack {BH}_{2}^{2 +} \right\rbrack}{0.1} \Rightarrow \left\lbrack {BH}_{2}^{2 +} \right\rbrack = 10^{- 18}M$
Subject: Chemistry — Physical Chemistry — 
Difficulty: Moderate

Question: A dry air is passed through the solution containing the 10 gm of
solute and 90 gm of water and then it pass through pure water. There is
the depression in weight of solution wt by 2.5 gm and in weight of pure
solvent by 0.05 gm. Calculate the molecular weight of solute.7


Answer: 100

Solution:
Lowering in weight of solution[IMAGE] solution
pressure
Lowering in weight of solvent[IMAGE] P^0 - P_s
([IMAGE] P^0 = vapour pressure of pure solvent)
Subject: Chemistry — Inorganic Chemistry — Metallurgy
Difficulty: Moderate

Question: Purpose of smelting of an ore is

1) To oxidize it
2) To reduce it
3) To remove vaporizable impurities
4) To obtain an alloy

Correct option: 2

Solution:
Smelting is a process of reducing metal oxide to metal by means
of coke or CO.
Fe_2 O_3 + 3C → 2Fe + 3CO
Fe_2 O_3 + 3CO → 2Fe + 3CO_2
Subject: Chemistry — Physical Chemistry — 
Difficulty: Moderate

Question: The freezing point (in ºC) of a solution containing 0.1 g of
K3[Fe(CN)6] (Mol. Wt. 329) in 100 g of water (Kf = 1.86 K kg mol-1)
is:
100 g ty (Kf = 1.86 K kg mol-1) esa 0.1 g K3[Fe(CN)6] (v.kq Hkkj =
329) ds ?kqyus

1) - 2.3 × 10-2
2) - 5.7 × 10-2
3) - 5.7 × 10-3
4) - 1.2 × 10-2

Correct option: 1

Solution:
$\Delta T_{f} = i \times K_{f} \times m$
$= 4 \times 1.86 \times \frac{0.1}{329 \times 0.1} = 2.3 \times 10^{- 2}$
$\Rightarrow T_{f} = 0 - 2.3 \times 10^{- 2} = - 2.3 \times 10^{- 2}\ ^{\circ}C$
Subject: Chemistry — Inorganic Chemistry — Hydrogen And Its Compound
Difficulty: Easy

Question: $H_{2}O_{2}$is always stored in black bottles because

1) It is highly unstable
2) Its enthalpy of decomposition is high
3) It undergo autooxidation on prolonged standing
4) None of these

Correct option: 3

Solution:
$H_{2}O_{2}$ is unstable liquid and decomposes into water and
oxygen either on standing or on heating.
Subject: Chemistry —  — 

Question: The heats of neutralization of four acids a, b, c, and d when
neutralised against a common strong base are 13.7, 9.4, 11.2 and 12.4
kcal respectively. The weakest among base these acids is.

1) a
2) b
3) c
4) d


Solution:
Weaker the acid lesser will be the heat of Neutralisation
∴ Acid is weakest among a, b, c and d
Subject: Chemistry —  — Simple Cubic Structure & BCC
Difficulty: Easy

Question: How many spherical balls of radii 2 cm can be placed completely
inside a cubical box of edge = 8 cm ?


Answer: 8

Solution:
a = 2 × diameter of the ball.
number of balls = 2 × 2 × 2 = 8
Subject: Chemistry — Hydrocarbon — Hydrocarbon
Difficulty: Easy

Question: To prepare But-2-yne from 2, 2, 3, 3-Tetrachlorobutane, reagent
used is

1) Zinc dust / $\Delta$
2) Sodamide
3) Alc. KOH
4) aq. KOH

Correct option: 1

Solution:
Subject: Chemistry — Inorganic Chemistry — D & F -Block Elements
Difficulty: Easy

Question: Which of the following statement is not true about Mohr's salt

1) It decolorises [IMAGE]
2) It is a primary standards
3) It is a double salt
4) Oxidation state of iron is +3 in this salt

Correct option: 3

Solution:
Oxidation state of iron in mohr's salt
Subject: Chemistry — Organic Chemistry — Organic Reaction mechanisms-II
Difficulty: Tough

Question: Which of the following reactions will yield 2,2-dibromopropane ?

1) ${CH}_{3} - C \equiv CH + 2HBr \longrightarrow$
2) ${CH}_{3}CH = CHBr + HBr \longrightarrow$
3) $CH \equiv CH + 2HBr \longrightarrow$
4) ${CH}_{3} - CH = {CH}_{2} + HBr \longrightarrow$

Correct option: 1

Solution:
Subject: Chemistry — Physical Chemistry — 
Difficulty: Moderate

Question: Hexagonal close packing is found in crystal lattice of

1) Na
2) Mg
3) Al
4) None of these

Correct option: 2

Solution:
Co-ordination number in HCP = 12
Co-ordination number in Mg is also = 12
Subject: Chemistry — Organic Chemistry — Some Basic Principles and Techniques
Difficulty: Easy

Question: Which resonating structure of 1-Methoxycyclohexa-1,3-diene is
impossible ?


Correct option: 3

Solution:
is impossible structure because o-atom does not have 10
electron in its valence shell.
Subject: Chemistry — Physical Chemistry — Chemical Equilibrium
Difficulty: Moderate

Question: For the reaction ${SO}_{2(g)} + \frac{1}{2}$
O_2(g)[IMAGE] SO_3(g), if KP = KC (RT)x where the
symbols have usual meaning then the value of x is: (assuming ideality)
vfHkfØ fy,$\ {SO}_{2(g)} + \frac{1}{2}$
O_2(g)[IMAGE] SO_3(g), ds fy, KP = KC(RT)x gksxk]
tgk¡ lHkh çrhd viuk ekurs gq, x

1) -1
2) $- \frac{1}{2}$
3) $\frac{1}{2}$
4) 1

Correct option: 2

Solution:
[IMAGE] Δng = - $\frac{1}{2}$
Subject: Chemistry — Organic Chemistry — Organic compounds containing Nitrogen
Difficulty: Moderate

Question: Which of the following reacts with [IMAGE] to give
phenol?


Correct option: 4

Solution:
Subject: Chemistry — Inorganic Chemistry — Thermodynamics
Difficulty: Tough

Question: Calculate $\Delta_{r}G^{\circ}$ for (NH4CI, s) at 310 K.
Given:$\ \Delta_{r}H^{\circ}$ (NH4CI, s)= -314.5 
$\Delta_{r}C_{p} = 0$
$S_{N_{2}(g)}^{o} = 192{JK}^{- 1}{mol}^{- 1}$
$S_{H_{2}(g)}^{\circ} = 130.5{JK}^{- 1}{mol}^{- 1}$
$S_{{Cl}_{2}}^{\circ}(g) = 233{JK}^{- 1}{mol}^{- 1}$
$S^{\circ}{NH}_{4}Cl(s) = 99.5{JK}^{- 1}{mol}^{- 1}$
All given data are at 300 K.

4) None of these

Correct option: 1

Solution:
$\Delta_{r}S^{\circ}\left( {NH}_{4}Cl,s \right)\ at\ 300K$
$= S_{{NH}_{4}Cl(s)}^{\circ} - \left\lbrack \frac{1}{2}S_{N_{2}}^{\circ} + 2S_{H_{2}}^{\circ} + \frac{1}{2}S_{{Cl}_{2}}^{\circ} \right\rbrack$
$= - 374{JK}^{- 1}{mol}^{- 1}$
$\Delta_{f}C_{P} = 0$
$\therefore\Delta_{f}S_{310}^{\circ} = \Delta_{f}S_{300}^{\circ}$
$= - 374{JK}^{- 1}{mol}^{- 1}$
$\Delta_{f}H_{310}^{\circ} = \Delta_{f}H_{300}^{\circ} = - 314.5$
$\Delta_{f}G_{310}^{\circ} = \Delta_{f}H^{\circ} - 310\Delta S^{\circ} = - 314.5 - \frac{310( - 374)}{1000} = - 198.56kJ/mol$
Subject: Chemistry —  — 

Question: Which of the following gases will have a greater tendency to get
adsorbed as compared to remaining gases?

1) O_2
2) CO
3) N_2
4) H_2


Solution:
CO because it is polar all other are non polar.
Subject: Chemistry — Inorganic Chemistry — Metallurgy
Difficulty: Moderate

Question: The final step for the extraction of copper from copper pyrite
in Bessemere converter involves the reaction

1) 4Cu_2 O + FeS → 8Cu + FeSO_4
2) Cu_2S + 2Cu_2 O → 6Cu + SO_2
3) 2Cu_2 O + FeS → 4Cu + Fe + SO_2
4) Cu_2 S + 2FeO → 2Cu + 2FeCO + SO_2

Correct option: 2

Solution:
In Bessemer converter copper sulphide is partially oxidized to
cuprous oxide which further reacts with remaining copper sulphide to
form copper and sulphur dioxide.
Cu_2S + 2Cu_2 O → 6Cu + SO_2
Subject: Chemistry — Physical Chemistry — Environmental Chemistry
Difficulty: Easy

Question: Which one of the following substances used in dry cleaning is
abetter strategy to control environmental pollution?

1) Tetrachloroethylene
2) Carbon dioxide
3) Sulphur dioxide
4) Nitrogen dioxide

Correct option: 2

Solution:
The use of carbon dioxide in dry cleaning does not increase
environmental pollution and thus is considered as a better strategy to
control environmental pollution. On the other hand, the substances such
as tetrachloroethylene, sulfur dioxide and nitrogen dioxide on being
used in dry cleaning, pollute the environment because of which their use
is not a better strategy. Thus, carbon dioxide is the substance which
can be used in drycleaning to control environmental pollution.
Subject: Chemistry — Physical Chemistry — Chemical Equilibrium
Difficulty: Easy

Question: Densities of diamond and graphite are 3.5 and 2.3 g/mL.
C (diamond) $\rightleftharpoons$ C (graphite) $\Delta$rH = - 1.9
favorable conditions for formation of diamond are

1) High pressure and low temperature
2) Low pressure and high temperature
3) High pressure and high temperature
4) Low pressure and low temperature

Correct option: 3

Solution:
High temperature will favour backward reaction as reaction is
exothermic. While on increasing pressure reaction will shift in
direction higher density.
Subject: Chemistry — Physical Chemistry — Atomic Structure
Difficulty: Moderate

Question: A d-block element has total spin value of +3 or -3 then the
magnetic moment of the element is approximately:
 d. +3 -3

1) 2.83 B.M.
2) 3.87 B.M.
3) 5.9 B.M. (4) 6.93 B.M.

Answer: 4

Solution:
Total spin = 3
[IMAGE] n = 6 n2
i.e. magnetic moment =[IMAGE] = [IMAGE] =
 = 3
[IMAGE] n = 6 n2
 = [IMAGE] = [IMAGE] =
Subject: Chemistry — Coordination Compounds — Valence Bond Theory and Crystal Field Theory (Part II)
Difficulty: Tough

Question: Which of the following is a high spin complex ?

1) $\left\lbrack Co\left( {NH}_{3} \right)_{6} \right\rbrack^{3 +}$
2) $\left\lbrack Fe(CN)_{6} \right\rbrack^{4 -}$
3) $\left\lbrack Ni(CN)_{4} \right\rbrack^{2 -}$
4) $\left\lbrack {FeF}_{6} \right\rbrack^{3 -}$

Correct option: 4

Solution:
The complex $\left\lbrack {FeF}_{6} \right\rbrack^{4 -}$ is
paramagnetic and uses outer orbital (4d) in hybridisation
$\left( {sp}^{3}d^{2} \right)$; it is thus called as outer orbital or
high spin or spin free complex. So:
$Fe^{24},\lbrack Ar\rbrack 3d^{6}$
[IMAGE] $\mathbf{sp}^{\mathbf{3}}\mathbf{d}^{\mathbf{2}}$hybrid orbitals
Six pairs of electrons from six $F^{-}$ ions
rFkk ckâ (4d) d) $\left( {sp}^{3}d^{2} \right)$ ladj.k
$Fe^{24},\lbrack Ar\rbrack 3d^{6}$
N $F^{-}$vk;uksa
Subject: Chemistry — Organic Chemistry — Organic Chemistry
Difficulty: Easy

Question: Most stable carbanion is


Correct option: 3

Solution:
Due to [IMAGE] group in benzene ring,
[IMAGE] is most stable carbanion.
Subject: Chemistry — Physical Chemistry — Mole concept
Difficulty: Moderate

Question: How many moles of potassium chlorate need to be heated to produce
11.2 liter oxygen at N.T.P.

1) $\frac{1}{2}$ mol
2) $\frac{1}{3}$ mol
3) $\frac{1}{4}$ mol
4) $\frac{2}{3}$ mol

Correct option: 2

Solution:
${KClO}_{3} \longrightarrow KCl + \frac{3}{2}O_{2}$
$\frac{3}{2}$ mole or 33.6 litre O2 from 1 mole KClO3
11.2 litre of O2 formed by mole KClO3