datavorous/entrance-exam-dataset huggingface dataset:
Which is not the correct statement? (At. nos. $\mathrm{Ce}=58, \mathrm{Lu}=71, \mathrm{La}=57, \mathrm{Yb}=70$ )

Options:
A Colour of $\mathrm{Yb}^{3+}$ ion is pink.
B $\mathrm{La}^{3+}$ is diamagnetic.
C $\mathrm{Ce}^{4+}$ has $f^{0}$ configuration.
D $\mathrm{Lu}^{3+}$ had $f^{14}$ configuration.

The correct answer is:
Colour of $\mathrm{Yb}^{3+}$ ion is pink.

Solution:
Option(a) is incorrect as $\mathrm{Yb}^{3+}$ is colorless.

Topic: Chemistry, d and f Block Elements, BITSAT, BITSAT 2020
Which law of the thermodynamics helps in calculating the absolute entropies of various substances at different temperatures?

Options:
A First law
B Second law
C Third law
D Zeroth law

The correct answer is:
Third law

Solution:
The third law helps to calculate the absolute entropies of pure substances at different temperature. The entropy of the substance at different temperature. $\mathrm{T}$ may be calculated by the measurement of heat capacity change

$$

\begin{array}{l}

\mathrm{S}_{\mathrm{T}}-\mathrm{S}_{0}=\Delta \mathrm{S}=\int_{0}^{\mathrm{T}} \frac{\mathrm{C}_{\mathrm{p}} \mathrm{dt}}{\mathrm{T}} \\

\text { Where } \mathrm{S}_{\mathrm{T}}=\text { Entropy at } \mathrm{T} \mathrm{K}

\end{array}

$$

$\mathrm{S}_{0}=$ Entropy at $0 \mathrm{~K}$

$$

\begin{array}{l}

=\mathrm{C}_{\mathrm{p}} \cdot \log _{e} \mathrm{~T} \\

=2.303 \mathrm{C}_{\mathrm{p}} \mathrm{log} \mathrm{T}

\end{array}

$$

Topic: Chemistry, Thermodynamics (C), BITSAT, BITSAT 2015
Which liberates ammonia when treated with water?

Options:
A $\mathrm{Li}_{3} \mathrm{~N}$
B $\mathrm{Mg}_{3} \mathrm{~N}_{2}$
C $\mathrm{CaCN}_{2}$
D All

The correct answer is:
All

Solution:
All nitrides react with $\mathrm{H}_{2} \mathrm{O}$ to give $\mathrm{NH}_{3}$ and $\mathrm{CaCN}_{2}$ also react with $\mathrm{H}_{2} \mathrm{O}$
$$
\mathrm{CaNCN}+3 \mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{CaCO}_{3}+\mathrm{NH}_{3}
$$

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2010
Which method is useful for the synthesis of ether?

Options:
A

B

C

D

The correct answer is:

Solution:
At $443 \mathrm{~K}$ compound in (d) will produce propene. In (a) alkene will be produced as tertiary halide and strong base favours elimination. In (b) reaction is not possibie at room temperature as due to resonance $\mathrm{C}-\mathrm{Cl}$ bond has partial double bond character which is very difficult to break.

Topic: Chemistry, Alcohols Phenols and Ethers, BITSAT, BITSAT 2023 (Memory Based Paper 1)
Which of the following 0.1 M aqueous solution will have lowest freezing point?

Options:
A Potassium sulphate
B Sodium chloride
C Urea
D Glucose

The correct answer is:
Potassium sulphate

Solution:
Potassium sulphate K2SO4, i=3

Sodium chloride NaCl, i=2

Urea, i=1

Glucose, i=1

Greater the value of i, greater lowering in freezing point and hence, lower will be the freezing temperature.

Therefore, K2SO4 solution has the lowest freezing point.

Topic: Chemistry, Solutions, BITSAT, BITSAT 2018
Which of the following according to LeChatelier's principle is correct?

Options:
A Increase in temperature favours the endothermic reaction
B Increase in temperature favours the exothermic reaction
C Increase in pressure shifts the equilibrium in that side in which number of gaseous moles increases
D All of the above are true

The correct answer is:
Increase in temperature favours the endothermic reaction

Solution:
According to Le-Chatelier's principle increase in temperature favours the endothermic reaction while decrease in temperature favour the exothermic reaction. Increase in pressure shifts the equilibrium in that side in which number of gaseous moles decreases.

Topic: Chemistry, Chemical Equilibrium, BITSAT, BITSAT 2015
Which of the following acts as an antioxidant in edible oils?

Options:
A Vitamin B
B Vitamin C
C Vitamin D
D Vitamin E

The correct answer is:
Vitamin E

Solution:
Vitamin $\mathrm{E}$ is an antioxidant present in edible oils.

Topic: Chemistry, Biomolecules, BITSAT, BITSAT 2021
Which of the following acts as the stationary phase in paper chromatography?

Options:
A
Water
B
Alumina
C
Silica gel
D
None of these

The correct answer is:
Water

Solution:
Chromatography paper contains water trapped in it, which acts as the stationary phase.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following among alkalimetal is most reactive?

Options:
A $\mathrm{Na}$
B $\mathrm{K}$
C $\mathrm{Rb}$
D $\mathrm{Cs}$

The correct answer is:
$\mathrm{Cs}$

Solution:
Amongst alkali metals, Cs is most reactive because of its lowest IE.

Topic: Chemistry, s Block Elements, BITSAT, BITSAT 2014
Which of the following are isoelectronic species?

I. C+H3

II. NH2-

III. NH4+

IV. NH3

Options:
A I, II and III
B II, III and IV
C I, II and IV
D II and I

The correct answer is:
II, III and IV

Solution:
I. Number of electrons in C+H3=6+3-1=8

II. Number of electrons in NH2-=7+2+1=10

III. Number of electrons in NH4+=7+4-1=10

IV. Number of electrons in NH3=7+3=10

Since, species with same number of electrons are called isoelectronic species, Hence, IInd,IIIrd and IVth are isoelectronic.

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2017
Which of the following arrangements does not represent the correct order of the property stated against it?

Options:
A $\mathrm{V}^{2+}<\mathrm{Cr}^{2+}<\mathrm{Mn}^{2+}<\mathrm{Fe}^{2+}$ :paramagnetic

behaviour
B $\mathrm{Ni}^{2+}<\mathrm{Co}^{2+}<\mathrm{Fe}^{2+}<\mathrm{Mn}^{2+}:$ ionic size
C $\mathrm{Co}^{3+}<\mathrm{Fe}^{3+}<\mathrm{Cr}^{3+}<\mathrm{Sc}^{3+}:$ stability in

aqueous solution
D $\mathrm{Sc}<\mathrm{Ti}<\mathrm{Cr}<\mathrm{Mn}:$ number of oxidation states

The correct answer is:
$\mathrm{V}^{2+}<\mathrm{Cr}^{2+}<\mathrm{Mn}^{2+}<\mathrm{Fe}^{2+}$ :paramagnetic

behaviour

Solution:
No Solution

Topic: Chemistry, Coordination Compounds, BITSAT, BITSAT 2016
Which of the following can be used to prevent the decomposition of $\mathrm{H}_2 \mathrm{O}_2$ ?

Options:
A
Urea
B
Formaldehyde
C
Formic acid
D
Ethanol

The correct answer is:
Urea

Solution:
Urea acts as stablising agent. It prevents the decomposition of $\mathrm{H}_2 \mathrm{O}_2$.

Topic: Chemistry, Hydrogen, BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following can possibly be used as analgesic without causing addiction and modification?

Options:
A morphine
B $\mathrm{N}$ -acetyl-para-aminophenol
C diazepam
D tetrahydrocatenol

The correct answer is:
$\mathrm{N}$ -acetyl-para-aminophenol

Solution:
No Solution

Topic: Chemistry, Chemistry in Everyday Life, BITSAT, BITSAT 2014
Which of the following cannot give iodometric titration?

Options:
A $\mathrm{Fe}^{3+}$
B $\mathrm{Cu}^{2+}$
C $\mathrm{Pb}^{2+}$
D $\mathrm{Ag}^{2+}$

The correct answer is:
$\mathrm{Fe}^{3+}$

Solution:
There is no reaction between $\mathrm{I}^{-}$ and $\mathrm{Fe}^{3+}$.

Topic: Chemistry, Redox Reactions, BITSAT, BITSAT 2011
Which of the following catalyst is used in preparation of high density polythene?

Options:
A
Peroxide catalyst
B
Ziegler - Natta catalyst
C
Wilkinson's catalyst
D
Pd - catalyst

The correct answer is:
Ziegler - Natta catalyst

Solution:
High density polythene is formed when addition polymerisation of ethene takes place in a hydrocarbon solvent in presence of catalyst such as Ziegler-Natta catalyst.

Topic: Chemistry, Polymers, BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following chemicals can be added for sweetening of food items at cooking temperature and does not provides calories?

Options:
A Sucrose
B Glucose
C Aspartame
D Sucralose

The correct answer is:
Sucralose

Solution:
Sucralose is trichloro derivative of sucrose. It is stable at cooking temperture. It does not provide calories.

Topic: Chemistry, Chemistry in Everyday Life, BITSAT, BITSAT 2021
Which of the following combinations of properties would be most desirable for a cooking pot?

Options:
A High specific heat and low conductivity.
B Low specific heat and high conductivity.
C High specific heat and high conductivity.
D Low specific heat and low conductivity.

The correct answer is:
Low specific heat and high conductivity.

Solution:
No Solution available

Topic: Physics, Thermal Properties of Matter, BITSAT, BITSAT 2009
Which of the following combinations would not result in the formation of a buffer solution?

Options:
A $\mathrm{NH}_{3}+\mathrm{HCl}$
B $\mathrm{NH}_{4} \mathrm{Cl}+\mathrm{NH}_{3}$
C $\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{NaCl}$
D $\mathrm{NaOH}+\mathrm{CH}_{3} \mathrm{COOH}$

The correct answer is:
$\mathrm{NaOH}+\mathrm{CH}_{3} \mathrm{COOH}$

Solution:
Combination of $\mathrm{NaOH}$ and $\mathrm{CH}_{3} \mathrm{COOH}$ is the mixture of alkali and acetic acid. Therefore this combination can not be buffer forming solution.

Topic: Chemistry, Ionic Equilibrium, BITSAT, BITSAT 2012
Which of the following compound can not be used in preparation of iodoform?

Options:
A $\mathrm{CH}_{3} \mathrm{CHO}$
B $\mathrm{CH}_{3} \mathrm{COCH}_{3}$
C $\mathrm{HCHO}$
D 2 -propanol

The correct answer is:
$\mathrm{HCHO}$

Solution:
Formaldehyde can not produce
-group
on reaction with
potassium iodide and sod. hypochlorite vield iodoform.

Topic: Chemistry, Aldehydes and Ketones, BITSAT, BITSAT 2009
Which of the following compound does not follow Huckel's rule?

Options:
A

B

C

D

The correct answer is:

Solution:
An aromatic compound can follow Huckel's rule if it has (4n+2)π-electrons

where, n= integer 0,1,2,3,… etc.

Thus,

(a) n=0; 4×0+2=2π

∴ follow Huckel's rule

(b) n=1; Number of π-electrons =6

∴ follows Huckels rules.

(c) n=1; Number of π-electrons =6

∴ follows Huckel's rule.

(d) n=1, Number of π-electrons =8

(4n+2=4×1+2=6)

but this compound has 8 electrons which distorts the plane and hence does not follows Huckel's rule.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2017
Which of the following compound has all the four types $\left(1^{\circ}, 2^{\circ}, 3^{\circ}\right.$ and $\left.4^{\circ}\right)$ of carbon atoms?

Options:
A 2,3,4 -Trimethylpentane
B neo-Pentane
C 2,2,4 -Trimethylpentane
D None of the three

The correct answer is:
2,2,4 -Trimethylpentane

Solution:
$\mathrm{C}_{1}$ and $\mathrm{C}_{5}$ are $1^{\circ}, \mathrm{C}_{3}$ is $2^{\circ}, \mathrm{C}_{4}$ is $3^{\circ},$ and $\mathrm{C}_{2}$ is $4^{\circ}$

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2016
Which of the following compound is not chiral?

Options:
A $\mathrm{DCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}$
B $\mathrm{CH}_{3} \mathrm{CHDCH}_{2} \mathrm{Cl}$
C $\mathrm{CH}_{3} \mathrm{CHClCH}_{2} \mathrm{D}$
D $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHDCl}$

The correct answer is:
$\mathrm{DCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}$

Solution:
None of the carbon atoms in $\mathrm{DCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}$ is chiral i.e., each carbon
atom is achiral (symmetric).

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2011
Which of the following compound is obtained by heating ammonium cyanate?

Options:
A Alkane
B Urea
C Ethylamine
D Ammonium thiocyanate

The correct answer is:
Urea

Solution:
Urea is obtained by heating ammonium cyanate
$$
\mathrm{NH}_{4} \mathrm{CNO} \stackrel{\Delta}{\longrightarrow} \mathrm{NH}_{2} \mathrm{CONH}_{2}
$$
Ammonium cyanate Urea

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2009
Which of the following compound will give blood red colour while doing the Lassaigne's test for N.

Options:
A NH22C=O
B

H2NC6H4SO3H

C C6H5SO3H
D CHCl3

The correct answer is:

H2NC6H4SO3H

Solution:
When nitrogen and sulphur both are present in the organic compound, they combine during fusion to form sodium thiocyanate (sulphocyanide).

Thus, the compounds containing both N and S give blood red colour in Lassaigne's test due to the formation of FeSCN2. Thus, H2NC6H4SO3H gives blood red colour in Lassaigne's test of nitrogen.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2018
Which of the following compounds contain all the carbon atoms in the same hybridisation state

Options:
A H-C≡C-C≡C-H
B CH3-C≡C-CH3
C CH2=C=CH2
D CH2=CH-C≡CH

The correct answer is:
H-C≡C-C≡C-H

Solution:
Key idea pi-bond do not participate in hybridisation

In H−C≡C−C=−H all carbon atoms are in same hybridization state i.e., spâ hybridized.

a. H-Csp≡Csp-Csp≡Csp-H

b. CH3sp3-Csp≡Csp-CH3sp3

c. CH2sp2=Csp=CH2sp2

d. CH2sp2=CH-sp2Csp≡CHsp

Topic: Chemistry, Hydrocarbons, BITSAT, BITSAT 2019
Which of the following compounds has wrong IUPAC name?

Options:
A
B
C
D

The correct answer is:

Solution:
No Solution

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2014
Which of the following compounds is thermodynamically is the most stable?

Options:
A
$\mathrm{BaCO}_3$

B
$\mathrm{MgCO}_3$

C
$\mathrm{SrCO}_3$

D
$\mathrm{CaCO}_3$

The correct answer is:

$\mathrm{BaCO}_3$

Solution:
The thermal stability of carbonates increases down the group. So, the order of thermal stability of carbonates of alkaline earth metals is
$$
\mathrm{BaCO}_3>\mathrm{CaCO}_3>\mathrm{MgCO}_3>\mathrm{BeCO}_3 .
$$
Therefore, $\mathrm{BaCO}_3$ is thermodynamically most stable and $\mathrm{BeCO}_3$ is least stable.

Topic: Chemistry, s Block Elements, BITSAT, BITSAT 2022
Which of the following compounds, on reaction with NaOH and Na2O2 gives yellow colour?

Options:
A ZnOH2
B AlOH3
C CrOH3
D CaCO3

The correct answer is:
CrOH3

Solution:
Chromium hydroxide, i.e.CrOH3 when reacts with NaOH and Na2O2, gives yellow colour of sodium chromate. The whole reaction is as follows

3Na2O2+2CrOH3⟶2Na2CrO4(yellow)+2H2O+2NaOH

Topic: Chemistry, Practical Chemistry, BITSAT, BITSAT 2019
Which of the following diatomic molecules would be stabilised by the removal of an electron?

Options:
A C2
B CN
C N2
D O2

The correct answer is:
O2

Solution:
In O2, molecule, last two electrons are present in anti bonding
orbitals.
O28+8=16=σ1 s2,σ*1 s2,σ2 s2,σ*2 s2, σ2pz2,π2px2=π2py2,π*2px1=π*2py1
Removal of one electron from the O2, molecule gives O2+ in which the number of anti bonding electrons is one less and hence, BO increases. Thus, removal of one electron from O2 stabilises the molecule.

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2018
Which of the following does not contain any coordinate bond?

Options:
A $\mathrm{H}_{3} \mathrm{O}^{+}$
B $\mathrm{BF}_{4}{ }^{-}$
C $\mathrm{HF}_{2}{ }^{-}$
D $\mathrm{SO}_{2}{ }^{-}$

The correct answer is:
$\mathrm{HF}_{2}{ }^{-}$

Solution:
$\mathrm{HF}_{2}$ is the only compound among the given options which does not contain any coordinate bond because it has hydrogen bonding.

$[\mathrm{H}-\mathrm{F} \bullet \bullet \bullet \mathrm{H}]^{-}$

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2021
Which of the following does not have valence electron in $3 d$ -subshell?

Options:
A Fe(III)
B $\mathrm{Mn}(\mathrm{II})$
C $\mathrm{Cr}(\mathrm{I})$
D $\mathrm{P}(0)$

The correct answer is:
$\mathrm{P}(0)$

Solution:
$\mathrm{P}$ (At no. 15 ) has electronic configuration $1 s^{2}, 2 s^{2} p^{6}, 3 s^{2} p^{3},$ hence no electron in $d$ -subshell.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, BITSAT, BITSAT 2012
Which of the following electromagnetic radiations has the smallest wavelength?

Options:
A Ultraviolet rays
B X-rays
C $\gamma$ -rays
D Microwaves

The correct answer is:
$\gamma$ -rays

Solution:
No Solution

Topic: Physics, Electromagnetic Waves, BITSAT, BITSAT 2013
Which of the following elements does not belong to first transition series?

Options:
A $\mathrm{Fe}$
B $\mathrm{V}$
C $\mathrm{Ag}$
D $\mathrm{Cu}$

The correct answer is:
$\mathrm{Ag}$

Solution:
No Solution available

Topic: Chemistry, d and f Block Elements, BITSAT, BITSAT 2009
Which of the following elements mostly form covalent compounds?

Options:
A Cs
B Rb
C K
D Li

The correct answer is:
Li

Solution:
First member of 1st group i.e. lithium, mostly form covalent compounds due to its small size and comparatively high I.E. (with respect to other members of its group).

Covalent character depends upon the atomic radii. Smaller the atomic radii, more the covalent character i.e. the covalent character is inversely proportional to atomic radii.

Topic: Chemistry, s Block Elements, BITSAT, BITSAT 2017
Which of the following esters cannot undergo Claisen self condensation?

Options:
A $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOC}_{2} \mathrm{H}_{5}$
B $\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{COOC}_{2} \mathrm{H}_{5}$
C $\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{CH}_{2} \mathrm{COOC}_{2} \mathrm{H}_{5}$
D $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{COOC}_{2} \mathrm{H}_{5}$

The correct answer is:
$\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{COOC}_{2} \mathrm{H}_{5}$

Solution:
Claisen condensation is given by esters having two $\alpha$ -hydrogen atoms.

Topic: Chemistry, Aldehydes and Ketones, BITSAT, BITSAT 2011
Which of the following exhibit only+ 3 oxidation state?

Options:
A $\mathrm{U}$
B Th
C $\mathrm{Ac}$
D $\mathrm{Pa}$

The correct answer is:
$\mathrm{Ac}$

Solution:
$\mathrm{Ac}(89)=[\mathrm{Rn}]\left[6 d^{1}\right]\left[7 s^{2}\right]$

Topic: Chemistry, Structure of Atom, BITSAT, BITSAT 2011
Which of the following expression is correct for the rate of reaction given below ?

5Br-aq+BrO3-aq+6H+aq⟶3Br2aq+3H2Ol

Options:
A ΔBr-Δt=56ΔH+Δt
B ΔBr-Δt=65ΔH+Δt
C ΔBr-Δt=5ΔH+Δt
D ΔBr-Δt=6ΔH+Δt

The correct answer is:
ΔBr-Δt=56ΔH+Δt

Solution:
The given chemical reaction is

5Br-aq+BrO3-aq+6H+aq⟶3Br2aq+3H2Ol

Rate law expression for the given reaction can be written as

-15ΔBr-Δt=-ΔBrO3-Δt

-16ΔH+Δt=+13ΔBr2Δt

⇒-ΔBr-Δt=-5ΔBrO3-Δt=-56ΔH+Δt

ΔBr-Δt=56ΔH+Δt

Topic: Chemistry, Chemical Kinetics, BITSAT, BITSAT 2018
Which of the following expressions corresponds to simple harmonic motion along a straight line, where $x$ is the displacement and $a, b, c$ are positive constants?

Options:
A $a+b x-c x^{2}$
B $b x^{2}$
C $a-b x+c x^{2}$
D $-b x$

The correct answer is:
$-b x$

Solution:
In linear S.H.M., the restoring force acting on particle should always be proportional to the displacement of the particle and directed towards the equilibrium position. i.e., $\mathrm{F} \propto \mathrm{x}$
or $\mathrm{F}=-\mathrm{bx}$ where $\mathrm{b}$ is a positive constant.

Topic: Physics, Oscillations, BITSAT, BITSAT 2011
Which of the following factors affect the basic strength of amine?
(i) Inductive effect
(ii) Steric hinderance
(iii) Solvation effect
(iv) Solubility in organic solvents.

Options:
A (i) and (iv)
B (i), (ii) and (iii)
C (ii) and (iii)
D (ii) and (iv)

The correct answer is:
(i), (ii) and (iii)

Solution:
Inductive effect, steric hinderance and solvation effect the basic strength of amines.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2023 (Memory Based Paper 1)
Which of the following fluorides of xenon is impossible?

Options:
A $\mathrm{XeF}_{2}$
B $\mathrm{XeF}_{3}$
C $\mathrm{XeF}_{4}$
D $\mathrm{XeF}_{6}$

The correct answer is:
$\mathrm{XeF}_{3}$

Solution:
Xe $\mathrm{F}_{2}:$ Hybridization $\mathrm{sp}^{3} \mathrm{~d}$

Linear

Xe $\mathrm{F}_{4}:$ Hybridization $\mathrm{sp}^{3} \mathrm{~d}^{2}$

Square planar

$\mathrm{XeF}_{6}:$ Hybribisation $\mathrm{sp}^{3} \mathrm{~d}^{3}$

Pentagonal pyramidal or distorted octahedral

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2015
Which of the following functions is differentiable at \(x=0\) ?

Options:
A \(\cos (|x|)+|x|\)
B \(\cos (|x|)-|x|\)
C \(\sin (|x|)+|x|\)
D \(\sin (|x|)-|x|\)

The correct answer is:
\(\sin (|x|)-|x|\)

Solution:
\(|x|\) is non-differentiable function at
\(\begin{aligned}
& x=0 \text { as L.H.D }=-1 \text { and R.H. } \mathrm{D}=1 \\
& \because|x|=\left\{\begin{array}{cl}
x, & x \geq 0 \\
-x, & x < 0
\end{array}\right.
\end{aligned}\)
But \(\cos |h|\) is differentiable
\(\therefore\) Any combination of two such functions will be non-differentiable. Hence option (a) and (b) are ruled out.
Now, consider \(\sin |x|+|x|\)
\(\begin{aligned} & L^{\prime}=\lim _{h \rightarrow 0} \frac{\sin |-h|+|-h|}{-h}=\lim _{h \rightarrow 0} \frac{\sin h}{-h}-1=-1-1 =-2 \\ & R^{\prime}=\lim _{h \rightarrow 0} \frac{\sin |h|+|h|}{h}=\lim _{h \rightarrow 0} \frac{\sin h}{h}+1=1+1=2 \\ & \text { Consider } \sin |x|-|x| \\ & L^{\prime}=\lim _{h \rightarrow 0} \frac{\sin |-h|-|-h|}{-h}=\lim _{h \rightarrow 0} \frac{\sin h}{-h}+1=0 \\ & \end{aligned}\)

Topic: Mathematics, Quadratic Equation, BITSAT, BITSAT 2010
Which of the following gas molecules have maximum value of enthalpy of physisorption?

Options:
A $\mathrm{C}_{2} \mathrm{H}_{6}$
B $\mathrm{Ne}$
C $\mathrm{H}_{2} \mathrm{O}$
D $\mathrm{H}_{2}$

The correct answer is:
$\mathrm{H}_{2} \mathrm{O}$

Solution:
The more the liquifiable nature of a gas, the more is the enthalpy of adsorption. Water is more liquifiable.

Topic: Chemistry, Surface Chemistry, BITSAT, BITSAT 2012
Which of the following graph is correctly represented according to Freundlich isotherm.

Options:
A

B

C

D

The correct answer is:

Solution:
According to Freundlich adsorption isotherm,
x/m=k×P1n
where, x= mass of gas adsorbed on mass 'm' of the absorbent at pressure p.

k and n= constants.

Taking logarithm on both sides, we get
logx/m=logk+1nlogp

This is equation of a straight line with slope of 1n and intercept of logk.

Topic: Chemistry, Surface Chemistry, BITSAT, BITSAT 2018
Which of the following halides is not oxidized by $\mathrm{MnO}_{2}$

Options:
A $\mathrm{F}^{-}$
B $\mathrm{Cl}^{-}$
C $\mathrm{Br}^{-}$
D $\Gamma$

The correct answer is:
$\mathrm{F}^{-}$

Solution:
$\mathrm{F}_{2}$ is strongest oxidising agent. $\mathrm{F}^{-}$ is not oxidised by $\mathrm{MnO}_{2}$

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2011
Which of the following halogens exhibit only one oxidation state in its compounds?

Options:
A Bromine
B Chlorine
C Fluorine
D Iodine

The correct answer is:
Fluorine

Solution:
Fluorine, since it is the most electronegative element.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2014
Which of the following has correct increasing basic strength?

Options:
A $\mathrm{MgO}<\mathrm{BeO}<\mathrm{CaO}<\mathrm{BaO}$
B $\mathrm{BeO}<\mathrm{MgO}<\mathrm{CaO}<\mathrm{BaO}$
C $\mathrm{BaO}<\mathrm{CaO}<\mathrm{MgO}<\mathrm{BeO}$
D $\mathrm{CaO}<\mathrm{BaO}<\mathrm{BeO}<\mathrm{MgO}$

The correct answer is:
$\mathrm{BeO}<\mathrm{MgO}<\mathrm{CaO}<\mathrm{BaO}$

Solution:
The basic character of oxides increases down the group.

Topic: Chemistry, s Block Elements, BITSAT, BITSAT 2012
Which of the following has minimum melting point?

Options:
A $\mathrm{CsF}$
B $\mathrm{HCl}$
C $\mathrm{HF}$
D $\mathrm{LiF}$

The correct answer is:
$\mathrm{HCl}$

Solution:
Ionic compounds have high melting point. Greater the ionic character, more is melting point. $\mathrm{HCl}$ has least ionic character because of maximum electronegativity difference between the two constituent elements, ( $\mathrm{H}$ and $\mathrm{Cl}$ ) among $\mathrm{CsF}, \mathrm{HCl}, \mathrm{HF}$ and $\mathrm{LiF}$

$\therefore \mathrm{HCl}$ has minimum melting point.

Topic: Chemistry, s Block Elements, BITSAT, BITSAT 2021
Which of the following has square planar geometry?

Options:
A $\left[\mathrm{PtCl}_{4}\right]^{2-}$
B $\left[\mathrm{NiCl}_{4}\right]^{2-}$
C $\left[\mathrm{ZnCl}_{4}\right]^{2-}$
D $\left[\mathrm{CoCl}_{4}\right]^{2-}$

The correct answer is:
$\left[\mathrm{PtCl}_{4}\right]^{2-}$

Solution:
$\left[\mathrm{PtCl}_{4}\right]^{2-}$ has square planar geometry. $\mathrm{Pt}: 5 d^{9} 6 s^{1}$
Two electrons are removed from $5 d$ shell and $6 s$ shell. So, hybridisation takes place is $d s p^{2}$ i.e. square planar geometry.

Topic: Chemistry, Coordination Compounds, JEE Main