datavorous/entrance-exam-dataset huggingface dataset:
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, BITSAT, BITSAT 2010
Which of the following has the highest $p \pi-p \pi$ bonding tendency?

Options:
A $N$
B $P$
C $As$
D $Sb$

The correct answer is:
$N$

Solution:
Nitrogen due to small size is able to show $p \pi-p \pi$ lateral overlap forming $\mathrm{N} \equiv \mathrm{N}$, rest elements due to bigger size are not able to show $p \pi-p \pi$ lateral overlap.

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2021
Which of the following has the largest number of moles?

Options:
A 8 g of oxygen atoms
B 16 g of oxygen gas
C 14 g of nitrogen gas N2
D All have the same number of moles

The correct answer is:
All have the same number of moles

Solution:
∵ n=(actual mass) (molar mass)

(a) n=wm=816=12 mole

(b) n=1632=12 mole

(c) n=1428=12 mole

(d) Thus, all have the same number of moles.

Topic: Chemistry, Some Basic Concepts of Chemistry, BITSAT, BITSAT 2017
Which of the following has two stereoisomers?

Options:
A None of these
B Only I
C Only III
D $\mathrm{I}$ and III

The correct answer is:
Only I

Solution:
A rapid umbrella type inversion rapidly converts the structure III to its enantiomer; hence the two enantiomers are not separable.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2016
Which of the following has zero dipole moment?

Options:
A 1,1 -dichloromethane
B cis -1,2 -dichloroethene
C trans -1,2 -dichloroethene
D 1 -chloroethane

The correct answer is:
trans -1,2 -dichloroethene

Solution:
No Solution available

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2009
Which of the following ionic substances will be most effective in precipitating the sulphur sol?

Options:
A $\mathrm{KCl}$
B $\mathrm{BaCl}_{2}$
C $\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}$
D $\mathrm{Na}_{3} \mathrm{PO}_{4}$

The correct answer is:
$\mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}$

Solution:
No Solution

Topic: Chemistry, Surface Chemistry, BITSAT, BITSAT 2015
Which of the following ions can be separated by aq. $\mathrm{NH}_{4} \mathrm{OH}$ in presence of $\mathrm{NH}_{4} \mathrm{Cl}$

Options:
A $\mathrm{Al}^{3+}$ and $\mathrm{Fe}^{3+}$
B $\mathrm{Cr}^{3+}$ and $\mathrm{Al}^{3+}$
C $\mathrm{Cu}^{2+}$ and $\mathrm{Al}^{3+}$
D None of these

The correct answer is:
$\mathrm{Cu}^{2+}$ and $\mathrm{Al}^{3+}$

Solution:
$\mathrm{Cu}^{2+}$ is of group II and $\mathrm{Al}^{3+}$ is of group III of cation analysis.

Topic: Chemistry, Practical Chemistry, BITSAT, BITSAT 2014
Which of the following is a diamagnetic complex

Options:
A CoNH363+
B NiCl42-
C CuCl42-
D FeH2O63+

The correct answer is:
CoNH363+

Solution:
Among the given option (a) is a diamagnetic complex.

(a) CoNH363+⇒Co27⇒Co3+=3d64s0.

Thus, has no unpaired electrons and is a diamagnetic complex.

(b) NiCl42-⇒Ni28⇒Ni2+=3d84s0

Thus, has two unpaired electrons is paramagnetic.

(c) CuCl42-⇒Cu29⇒Cu2+=3d94s0

Thus, has one unpaired electrons and is paramagnetic.

(d) FeH2O63+⇒Fe26⇒Fe3+=3d54s0

Thus, has five unpaired electrons and is paramagnetic.

Topic: Chemistry, Coordination Compounds, BITSAT, BITSAT 2017
Which of the following is a hypnotic drug?

Options:
A
luminal
B
salol
C
catechol
D
chemisol

The correct answer is:
luminal

Solution:
These drugs induce sleep and are habit forming common example of hypnotic drugs are luminal and saconal.

Topic: Chemistry, Chemistry in Everyday Life, BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following is a strong base?

Options:
A $\mathrm{PH}_{3}$
B $\mathrm{AsH}_{3}$
C $\mathrm{NH}_{3}$
D $\mathrm{SbH}_{3}$

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

Solution:
Order of basic character is $\mathrm{NH}_{3}>\mathrm{PH}_{3}>$ $\mathrm{AsH}_{3}>\mathrm{SbH}_{3} .$ Basic-character decreases down the group from $\mathrm{N}$ to Bi due to increase in atomic size.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, BITSAT, BITSAT 2015
Which of the following is an incorrect set of quantum members?

Options:
A n=2, l=0, m=0
B n=1, l=0, m=0
C n=3, l=3, m=0
D n=2, l=1, m=1

The correct answer is:
n=3, l=3, m=0

Solution:
Maximum l value should be equal to n−1 and it cannot be equal to n.

∵ for (l) It can be upto (n-1) and

Thus, m=±l i.e. +l,0,-l

for (a) n=2,l=0,m=0 (correct),

for (b) n=1,l=0,m=0 (correct),

(c) n=3,l=3 (not correct),

(d) n=2,l=1,m=1 (correct),

Topic: Chemistry, Structure of Atom, BITSAT, BITSAT 2017
Which of the following is best nuclear fuel

Options:
A thorium 236
B plutonium 239
C $\quad$ uranium 236
D neptunium 239

The correct answer is:
plutonium 239

Solution:
Plutonium 239 is processed by breeder mechanism to be used as nuclear feul.

Topic: Physics, Nuclear Physics, BITSAT, BITSAT 2010
Which of the following is incorrect with respect to property indicated?

Options:
A $\mathrm{E} \cdot \mathrm{N}: \mathrm{F}>\mathrm{Cl}>\mathrm{Br}$
B $\quad$ E.A: $\mathrm{Cl}>\mathrm{F}>\mathrm{Br}$
C Oxidising power : $\mathrm{F}_{2}>\mathrm{Cl}_{2}>\mathrm{Br}_{2}$
D Bond energy : $\mathrm{F}_{2}>\mathrm{Cl}_{2}>\mathrm{Br}_{2}$

The correct answer is:
Bond energy : $\mathrm{F}_{2}>\mathrm{Cl}_{2}>\mathrm{Br}_{2}$

Solution:
$\mathrm{F}_{2}$ is expected to have highest bond energy but the correct decreasing order is $\mathrm{Cl}_{2}>\mathrm{Br}_{2}>\mathrm{F}_{2}$ because of fluorine atom has very small size due to which there is a high inter electronic repulsion between two fluorine atoms so the bond between two fluorine gets weaker and need less energy.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2013
Which of the following is less acidic among the given halogen compounds?

Options:
A $\mathrm{CHF}_{3}$
B $\mathrm{CH}_{3}$
C $\mathrm{CHCl}_{3}$
D $\mathrm{CHBr}_{3}$

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

Solution:
Due to stronger-I-effect of $\mathrm{F}$ than that of Cl, $\mathrm{CHF}_{3}$ should be more acidic than $\mathrm{CHCl}_{3} .$ But actually reverse is true.

This is due to : $\mathrm{CCl}_{3}^{-}$ left after the removal of a proton from $\mathrm{CHCl}_{3}$ is stabilised due to presence of $d$ -orbitals in

Cl than: $\mathrm{CF}_{3}^{-}$ left after the removal of a

proton from $\mathrm{CHF}_{3}$ which is not stabilised due to the absence of $d$ -orbitals on $\mathrm{F}$.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2013
Which of the following is most accurate?

Options:
A A screw gauge of least count $0.001 \mathrm{~mm}$.
B A screw gauge having pitch $1 \mathrm{~mm}$ and 50 divisions on circular scale.
C A vernier callipers of least count $0.01 \mathrm{~mm}$.
D Vernier callipers having 20 divisions on the sliding scale (vernier scale) coinciding 19 divisions on the main millimetre scale.

The correct answer is:
A screw gauge of least count $0.001 \mathrm{~mm}$.

Solution:
No Solution available

Topic: Physics, Experimental Physics, BITSAT, BITSAT 2009
Which of the following is not a disproportionation reaction?

Options:
A $\mathrm{P}_{4}+5 \mathrm{OH}^{-} \longrightarrow \mathrm{H}_{2} \mathrm{PO}_{2}^{-}+\mathrm{PH}_{3}$
B $\mathrm{Cl}_{2}+\mathrm{OH}^{-} \longrightarrow \mathrm{Cl}^{-}+\mathrm{ClO}$
C $2 \mathrm{H}_{2} \mathrm{O}_{2} \longrightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}$
D $\mathrm{PbO}_{2}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{PbO}+\mathrm{H}_{2} \mathrm{O}_{2}$

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

Solution:
Disproportionation involves simultaneous oxidation and reduction of the same atom in a molecule.

Topic: Chemistry, Redox Reactions, BITSAT, BITSAT 2020
Which of the following is not a vertex of the positive region bounded by the inqualities \(2 x+3 y \leq 6,5 x+3 y \leq 15\) and \(x, y \geq 0\)

Options:
A \((0,2)\)
B \((0,0)\)
C \((3,0)\)
D None of these

The correct answer is:
None of these

Solution:
Here \((0,2),(0,0)\) and \((3,0)\) all are vertices of feasible region.

Topic: Mathematics, Linear Programming, BITSAT, BITSAT 2011
Which of the following is not considered as an organometallic compound?

Options:
A cis-platin
B Ferrocene
C Zeise's salt
D Grignard reagent

The correct answer is:
cis-platin

Solution:
The structural formula of cis-platin is
Since no carbon is involved it is not a
organometallic compound.

Topic: Chemistry, Haloalkanes and Haloarenes, BITSAT, BITSAT 2011
Which of the following is not the product of dehydration of
?

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which of the following is not the product of dehydration of
?

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Alcohols Phenols and Ethers, BITSAT, BITSAT 2013
Which of the following is paramagnetic?

Options:
A $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$
B $\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]$
C $\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}$
D $\left[\mathrm{CoF}_{6}\right]^{3-}$

The correct answer is:
$\left[\mathrm{CoF}_{6}\right]^{3-}$

Solution:
$\mathrm{Fe}^{2+}$ electronic configuration is $[\mathrm{Ar}] 3 \mathrm{~d}^{6}$. Since CN is strong field ligand d electrons are paired . In $\mathrm{Ni}(\mathrm{CO})_{4} \mathrm{O} . \mathrm{S}$. of $\mathrm{Ni}$ is zero electronic configuration is $[\mathrm{Ar}\} 3 \mathrm{~d}^{8} 4 \mathrm{~s}^{2} . \mathrm{In}$

presence of $\mathrm{CO}$ it is $[\mathrm{Ar}] 3 \mathrm{~d}^{10} 4 \mathrm{~s}^{0},$ electrons are paired. Electronic configuration of $\mathrm{Ni}^{2+}$ $[\mathrm{Ar}] 3 \mathrm{~d}^{8} 4 \mathrm{~s}^{0},$ due to $\mathrm{CN}^{-}$ ligand all electrons

are paired. $\mathrm{Co}^{3+}$ is $[\mathrm{Ar}] 3 \mathrm{~d}^{6}$ since $\mathrm{F}$ is weak ligand hence paramagnetic.

Topic: Chemistry, Coordination Compounds, BITSAT, BITSAT 2016
Which of the following is process used for the preparation of acetone?

Options:
A Haber process
B Wacker process
C Wolff-Kishner reduction
D Gattermann-Koch synthesis

The correct answer is:
Wacker process

Solution:
In Wacker process, when mixture of propene and air is passed through mixture of $\mathrm{Pd}$ and $\mathrm{CuCl}_{2}$ at high pressure acetone is formed.
$\mathrm{Pd}+\mathrm{CuCl}_{2} \longrightarrow \mathrm{PdCl}_{2}+2 \mathrm{CuCl}$
$4 \mathrm{CuCl}+\mathrm{HCl}+\mathrm{O}_{2} \longrightarrow 4 \mathrm{CuCl}_{2}+2 \mathrm{H}_{2} \mathrm{O}$
$\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{PdCl}_{2}+\mathrm{H}_{2} \mathrm{O} \longrightarrow$
Propane
$\mathrm{CH}_{3} \mathrm{COCH}_{3}+\mathrm{Pd}+2 \mathrm{HCl}$

Topic: Chemistry, Aldehydes and Ketones, BITSAT, BITSAT 2012
Which of the following is similar to graphite

Options:
A $\underline{B}$
B $\mathrm{BN}$
C $\mathrm{B}_{2} \mathrm{H}_{6}$
D $\mathrm{B}_{4} \mathrm{C}$

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

Solution:
Graphite and boron nitride have similar structure.

Topic: Chemistry, p Block Elements (Group 13 & 14), BITSAT, BITSAT 2010
Which of the following is soluble in yellow ammonium sulphide?

Options:
A $\mathrm{CuS}$
B $\mathrm{CdS}$
C $\mathrm{SnS}$
D $\mathrm{PbS}$

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

Solution:
$\mathrm{SnS}+\left(\mathrm{NH}_{4}\right)_{2} \mathrm{~S}_{2} \rightarrow\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SnS}_{3}$ soluble

Topic: Chemistry, Practical Chemistry, BITSAT, BITSAT 2012
Which of the following is the correct order for the wavelength if absorption in the visible region.

Options:
A NiNO264-<NiNH362+<NiH2O62+
B NiNO264-<NiH2O62+<NiNH362+
C NiH2O62+<NiNH362+<NiNO264-
D NiNH362+<NiH2O62+<NiNO264-

The correct answer is:
NiNO264-<NiNH362+<NiH2O62+

Solution:
When central metal ion is same (here Ni2+ ), the absorption of colour depends on the ligand.

According to spectrochemical series, various ligands are as follows

I<Br-<Cl-<NO3-<F-<H2O

<NH3<NO2-<CN-<CO

Thus, H2O is the weakest ligand among these, therefore the absorbed energy will be lowest in
NiH2O62+, so it will absorb highest wavelength (red light).

E∝1λ

∴ The order of increasing wavelength is

NiNO264-<NiNH362+<NiH2O62+

Topic: Chemistry, Coordination Compounds, BITSAT, BITSAT 2018
Which of the following is the correct order of stability of conformations for NH2-CH2-CH2-OH.

Options:
A

gauche > eclipsed > anti

B gauche > anti > eclipsed
C eclipsed > gauche > anti
D anti > eclipsed > gauche

The correct answer is:
gauche > anti > eclipsed

Solution:
The anti conformation is most stable in which NH2 and OH groups are far apart as possible and minimum repulsion between two groups occurs.

In fully eclipsed conformation NH2 and OH groups are so close that the steric strain is maximum.

Since, gauche form is stabilised by intermolecular hydrogen bonding, hence it is more stable than anti.

Topic: Chemistry, General Organic Chemistry, BITSAT, BITSAT 2018
Which of the following is the most basic oxide?

Options:
A $\mathrm{Sb}_{2} \mathrm{O}_{3}$
B $\mathrm{Bi}_{2} \mathrm{O}_{3}$
C $\mathrm{SeO}_{2}$
D $\mathrm{Al}_{2} \mathrm{O}_{3}$

The correct answer is:
$\mathrm{Bi}_{2} \mathrm{O}_{3}$

Solution:
More the oxidation state of the central atom (metal) more is its acidity. Hence $\mathrm{SeO}_{2}(\mathrm{O} . \mathrm{S} .$ of $\mathrm{Se}=+4)$ is acidic. Further for a given O.S., the basic character of the oxides increases with the increasing size of the central atom. Thus $\mathrm{Al}_{2} \mathrm{O}_{3}$ and $\mathrm{Sb}_{2} \mathrm{O}_{3}$ are amphoteric and $\mathrm{Bi}_{2} \mathrm{O}_{3}$ is basic.

Topic: Chemistry, p Block Elements (Group 13 & 14), BITSAT, BITSAT 2015
Which of the following is used in the preparation of chlorine?

Options:
A Only $\mathrm{MnO}_{2}$
B $\quad$ Only $\mathrm{KMnO}_{4}$
C Both $\mathrm{MnO}_{2}$ and $\mathrm{KMnO}_{4}$
D Either $\mathrm{MnO}_{2}$, or $\mathrm{KMnO}_{4}$

The correct answer is:
Both $\mathrm{MnO}_{2}$ and $\mathrm{KMnO}_{4}$

Solution:
Both $\mathrm{MnO}_{2}$ and $\mathrm{KMnO}_{4}$ used for the preparation of chlorine by the action of conc. $\mathrm{HCl}$
$$
\begin{array}{l}
\mathrm{MnO}_{2}+4 \mathrm{HCl} \rightarrow \mathrm{MnCl}_{2}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{Cl}_{2} \\
2 \mathrm{KMnO}_{4}+16 \mathrm{HCl} \rightarrow 2 \mathrm{KCl}+2 \mathrm{MnCl}_{2} \\
+8 \mathrm{H}_{2} \mathrm{O}+5 \mathrm{Cl}_{2}
\end{array}
$$
Chlorine is not obtained by dil. $\mathrm{HCl}$
$$
\mathrm{Ag}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ag}_{2} \mathrm{~S}+\mathrm{H}_{2} \mathrm{SO}_{4}
$$

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2009
Which of the following is/are aromatic alcohol?

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

The correct answer is:
II and III

Solution:
The aromatic alcohols are those compounds in which the hydroxyl group is not directly attached to the nucleus but is linked to a carbon atom situated in a side-chain.

The compound-I and compound-II are the phenols, these are not the aromatic alcohols as -OH group is directly attached to benzene ring.

The compounds II and III are benzyl alcohols and these are aromatic alcohols as -OH group is attached to the carbon atom which itself attached to benzene ring.

Topic: Chemistry, Alcohols Phenols and Ethers, BITSAT, BITSAT 2019
Which of the following lanthanoid is diamagnetic?

Atomic no's Sm=62, Ce=58, Eu=63, Yb=70

Options:
A Sm2+
B Eu2+
C Yb2+
D Ce2+

The correct answer is:
Yb2+

Solution:
Electronic configuration of the given species are

a. Sm2+Z=62=Xe4f6 b. Eu2+Z=63=Xe4f7

c. Yb2+Z=70=Xe4f14 d. Ce2+Z=58=Xe4f15d1

On the basis of above electronic configuration, only Yb2+Z=70 has no unpaired electrons i.e. has fully-filled orbitals. Thus, it is diamagnetic in nature.

Topic: Chemistry, d and f Block Elements, BITSAT, BITSAT 2019
Which of the following Maxwell's equations is valid for time varying conditions but not valid for static conditions :

Options:
A $\oint \overrightarrow{\mathrm{B}} \cdot \overrightarrow{\mathrm{dl}}=\mu_0 \mathrm{I}$
B $\oint \overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{dl}}=0$
C $\oint \overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{dl}}=-\frac{\partial \phi_{\mathrm{B}}}{\partial \mathrm{t}}$
D $\oint \overrightarrow{\mathrm{D}} \cdot \overrightarrow{\mathrm{dA}}=\mathrm{Q}$

The correct answer is:
$\oint \overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{dl}}=-\frac{\partial \phi_{\mathrm{B}}}{\partial \mathrm{t}}$

Solution:
For time varying condition Maxwell's equation, $\oint \overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{dl}}=-\frac{\mathrm{d} \phi_{\mathrm{B}}}{\mathrm{dt}}$

Topic: Physics, Electromagnetic Waves, BITSAT, BITSAT 2023 (Memory Based Paper 1)
Which of the following metal is leached by cyanide process

Options:
A Ag
B Na
C Al
D Cu

The correct answer is:
Ag

Solution:
Cyanide process, which is also known as MacArthur cyanide process involves the extraction of gold and silver from their ores by dissolving them in a dilute solution of sodium cyanide or potassium cyanide. The leaching is carried out in the presence of air or oxygen to oxidise the metal.

Ag is leached by cyanide process by making the complex using NaCN/KCN as follows

Ag2S+4NaCN⟶2NaAg(CN)2Soluble+Na2S

Topic: Chemistry, General Principles and Processes of Isolation of Metals, BITSAT, BITSAT 2017
Which of the following method gives better yield of $p$ -nitrophenol?

Options:
A Phenol $\frac{\text { dil.HNO }_{3}}{20^{\circ} \mathrm{C}} p$ -Nitrophenol
B Phenol $\frac{\text { (i) } \mathrm{NaNO}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4}, 7-8^{\circ} \mathrm{C}}{\text { (ii) } \mathrm{HNO}_{3}}$

$p$ -Nitrophenol
C Phenol $\frac{\text { (i) } \mathrm{NaOH}}{\text { (ii) Conc. } \mathrm{HNO}_{3}}$,
D None of the three.

The correct answer is:
Phenol $\frac{\text { (i) } \mathrm{NaNO}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4}, 7-8^{\circ} \mathrm{C}}{\text { (ii) } \mathrm{HNO}_{3}}$

$p$ -Nitrophenol

Solution:
Thus here, oxidation of phenol is minimised by forming $p$ -nitrosophenol.

Topic: Chemistry, Hydrocarbons, BITSAT, BITSAT 2016
Which of the following method is used for coagulation of the sol?

Options:
A By mixing two oppositely charged sols.
B By electrophoresis.
C By addition of electrolytes.
D All of the above.

The correct answer is:
All of the above.

Solution:
No Solution Available

Topic: Chemistry, Surface Chemistry, BITSAT, BITSAT 2023 (Memory Based Paper 1)
Which of the following molecule/ion has all the three types of bonds, electrovalent, covalent and co-ordinate:

Options:
A $\mathrm{HCl}$
B $\mathrm{NH}_{4}^{+}$
C $\mathrm{Cl}^{-}$
D $\mathrm{H}_{2} \mathrm{O}_{2}$

The correct answer is:
$\mathrm{NH}_{4}^{+}$

Solution:
Bond structure of molecules are:

$\mathrm{HCl}=\mathrm{H}^{+}-\mathrm{Cl}^{-}$

hence, clearly $\mathrm{NH}_{4}^{+}$ ion contains all three types of bonds.

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2015
Which of the following molecules acts as a Lewis acid?

Options:
A $\left(\mathrm{CH}_3\right)_2 \mathrm{O}$
B $\left(\mathrm{CH}_3\right)_3 \mathrm{P}$
C $\left(\mathrm{CH}_3\right)_3 \mathrm{~N}$
D $\left(\mathrm{CH}_3\right)_3 \mathrm{~B}$

The correct answer is:
$\left(\mathrm{CH}_3\right)_3 \mathrm{~B}$

Solution:
According to Lewis concept "Acids are electron acceptor and bases are electron donor" Since, electron deficient compounds also have an ability to accept electrons, these are regarded as acids.
Trimethylborane \((\mathrm{CH})_3\) B have incomplete octet thus, act as Lewis acid.

Topic: Chemistry, Ionic Equilibrium, BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following must be known in order to determine the power output of an automobile?

Options:
A Final velocity and height
B Mass and amount of work performed
C Force exerted and distance of motion
D Work performed and elapsed time of work

The correct answer is:
Work performed and elapsed time of work

Solution:
Power is defined as the rate of doing work. For the automobile, the power output is the amount of work done (overcoming friction) divided by the length of time in which the work was done.

Topic: Physics, Work Power Energy, BITSAT, BITSAT 2012
Which of the following order is not correct?

Options:
A $\mathrm{MeBr}>\mathrm{Me}_{2} \mathrm{CHBr}>\mathrm{Me}_{3} \mathrm{CBr}>$
$\mathrm{Et}_{3} \mathrm{CBr}\left(\mathrm{S}_{\mathrm{N}} 2\right)$
B $\mathrm{Me}_{3} \mathrm{CBr}>\mathrm{Me}_{2} \mathrm{CHBr}>\mathrm{Me}_{2} \mathrm{CH.CH}_{2} \mathrm{Br}>$
$\mathrm{MeCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br} .\left(\mathrm{E}_{2}\right)$
C $\mathrm{PhCH}_{2} \mathrm{Br}>\mathrm{Ph} \mathrm{CHBrMe}>\mathrm{PhCBrMe}_{2}>$
$\operatorname{PhCBrMePh}\left(\mathrm{S}_{\mathrm{N}} 1\right)$
D $\mathrm{MeI}>\mathrm{MeBr}>\mathrm{MeCl}>\mathrm{MeF}\left(\mathrm{S}_{\mathrm{N}} 2\right)$

The correct answer is:
$\mathrm{PhCH}_{2} \mathrm{Br}>\mathrm{Ph} \mathrm{CHBrMe}>\mathrm{PhCBrMe}_{2}>$
$\operatorname{PhCBrMePh}\left(\mathrm{S}_{\mathrm{N}} 1\right)$

Solution:
The more is the stability of intermediate carbonium ion, the more is the chance of $\mathrm{S}_{\mathrm{N}} 1$ mechanism. The intermediates obtained will be
$\mathrm{Ph}^{+} \mathrm{C} \mathrm{H}_{2}(\mathrm{i}), \mathrm{Ph} \mathrm{C} \mathrm{H}-\mathrm{Me}(\mathrm{ii})$
$\mathrm{Ph} \mathrm{C}-\mathrm{Me}_{2}\left(\right.$ iii) $, \mathrm{Ph} \mathrm{C}^{+} \mathrm{MePh}$ (iv)
The stabilty is of the order iv $>\mathrm{iii}>\mathrm{ii}>\mathrm{i}$

Topic: Chemistry, Haloalkanes and Haloarenes, BITSAT, BITSAT 2009
Which of the following oxo acid of sulphur has O-O bond?

Options:
A $\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_7$
B $\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_8$
C $\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_6$
D $\mathrm{H}_2 \overline{\mathrm{S}}_2 \mathrm{O}_5$

The correct answer is:
$\mathrm{H}_2 \mathrm{~S}_2 \mathrm{O}_8$

Solution:

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), BITSAT, BITSAT 2023 (Memory Based Paper 2)
Which of the following pairs has both members from the same period of periodic table:

Options:
A $\mathrm{Na}, \mathrm{Ca}$
B $\mathrm{Na}, \mathrm{Cl}$
C $\mathrm{Ca}, \mathrm{Cl}$
D $\mathrm{Cl}, \mathrm{Br}$

The correct answer is:
$\mathrm{Na}, \mathrm{Cl}$

Solution:
$_{11} \mathrm{Na} \Rightarrow 2,8,1 ;{ }_{17} \mathrm{Cl} \Rightarrow 2,8,7$
These have same number of shells. Hence, they are the elements of the same period.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, BITSAT, BITSAT 2010
Which of the following pairs has the same size?

Options:
A $\mathrm{Fe}^{2+}, \mathrm{Ni}^{2+}$
B $\mathrm{Zr}^{4+}, \mathrm{Ti}^{4+}$
C $\mathrm{Zr}^{4+}, \mathrm{Hf}^{4+}$
D $\mathrm{Zn}^{2+}, \mathrm{Hf}^{4+}$

The correct answer is:
$\mathrm{Zr}^{4+}, \mathrm{Hf}^{4+}$

Solution:
Due to lanthanide contraction, the size of $\mathrm{Zr}$ and $\mathrm{Hf}$ (atom and ions) become nearly similar.

Topic: Chemistry, d and f Block Elements, BITSAT, BITSAT 2011
Which of the following pairs will form the most stable ionic bond?

Options:
A $\mathrm{Na}$ and $\mathrm{Cl}$
B $\mathrm{Mg}$ and $\mathrm{F}$
C $\mathrm{Li}$ and $\mathrm{F}$
D $\mathrm{Na}$ and F

The correct answer is:
$\mathrm{Mg}$ and $\mathrm{F}$

Solution:
The stability of the ionic bond depends upon the lattice energy which is expected to be more between $\mathrm{Mg}$ and $\mathrm{F}$ due to +2 charge on Mg atom.

Topic: Chemistry, Chemical Bonding and Molecular Structure, BITSAT, BITSAT 2023 (Memory Based Paper 1)
Which of the following pollutants is main product of automobiles exhaust?

Options:
A $\mathrm{CO}$
B $\mathrm{CO}_{2}$
C $\mathrm{NO}$
D Hydrocarbons

The correct answer is:
$\mathrm{NO}$

Solution:
NO pollutant is the main product of automobiles exhaust.

Topic: Chemistry, Environmental Chemistry, BITSAT, BITSAT 2015