datavorous/entrance-exam-dataset huggingface dataset:
When does the clear boundary between the liquid and vapor phases disappear?

Options:
A When the liquid becomes more dense than the vapor
B When the vapor becomes denser than the liquid
C When the temperature decreases
D When the density of the liquid and vapors becomes the same

The correct answer is:
When the density of the liquid and vapors becomes the same

Solution:
The clear boundary between the liquid and vapor phases disappears when the density of the liquid and vapors becomes the same.

Topic: Chemistry, States of Matter, NEET
When is the dehydrogenation method suitable for preparing aldehydes and ketones?

Options:
A When using non-volatile alcohols
B When using primary alcohols
C When using secondary alcohols
D When using volatile alcohols

The correct answer is:
When using volatile alcohols

Solution:
The paragraph mentions that the dehydrogenation method is suitable for volatile alcohols.

Topic: Chemistry, Aldehydes, Ketones and Carboxylic Acids, NEET
When light propagates through a given homogeneous medium, the velocities of

Options:
A primary wavefront are larger than those of secondary wavelets.
B primary wavefronts are lesser than those of secondary wavelets.
C primary wavefronts are greater than or equal to those of secondary wavelets.
D primary wavefront and wavelets are equal:

The correct answer is:
primary wavefront and wavelets are equal:

Solution:
According to Huygen's principle, in
homogeneous medium, velocity of primary wavefront is equal to velocity of secondary wavelets.

Topic: Physics, Wave Optics, KCET, KCET 2023
When man eats fish which feeds on zooplanktons which have eaten small plants, the producer in this chain is:

Options:
A small plants
B fish
C man
D zooplankton

The correct answer is:
small plants

Solution:
A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism cats another.
The food chain is represented as:
Small plants $\rightarrow$ zooplanktons $\rightarrow$ Fish $\rightarrow$ Man
Primary Producer $\rightarrow$ Primary consumer $\rightarrow$ Sccondary consumer $\rightarrow$ Tertiary consumer
Related Theory

Topic: Biology, Ecosystem, NEET, NEET 2013 (Karnataka)
When open pipe is closed from one end then third overtone of closed pipe is higher in frequency by $150 \mathrm{~Hz}$ than second overtone of open pipe. The fundamental frequency of open end pipe will be

Options:
A 300Hz
B 500Hz
C 200Hz
D 400Hz

The correct answer is:
300Hz

Solution:
$3^{\mathrm{rd}}$ overtone of closed pipe $=7 \mathrm{n}_{\mathrm{oc}}=\frac{7 \mathrm{v}}{4 \ell}$
$2^{\text {nd }}$ overtone of closed pipe $=3 \mathrm{n}_{00}=\frac{3 \mathrm{v}}{2 \ell}$
Now, $\frac{7 \mathrm{v}}{4 \ell}=\frac{3 \mathrm{v}}{2 \ell}+150$
$\frac{7 v}{4 \ell}-\frac{3 v}{2 \ell}=150$
$\frac{7 v-6 v}{4 \ell}=150$
$\frac{v}{4 \ell}=150$
$\begin{array}{ll}\therefore \quad \ell= & \frac{v}{4 \times 150} \\ \therefore \quad & n_{00}=\frac{v}{2 \ell}=\frac{v \times 4 \times 150}{2 \times v}=300 \mathrm{~Hz}\end{array}$

Topic: Physics, Waves and Sound, MHT CET, MHT CET 2020 (16 Oct Shift 1)
When reaction is carried out at standard states then, at the equilibrium

Options:
A $\Delta H^{\circ}=0$
B $\Delta S^{\circ}=0$
C equilibrium constant $(k)=0$
D equilibrium constant $(k)=1$

The correct answer is:
equilibrium constant $(k)=1$

Solution:
We know,
$$
\Delta G^{\circ}=-R T \ln \frac{[k]}{[q]}
$$
where, $q=$ reaction quotient
$$
k=\text { equilibrium constant. }
$$
$\because$ At equilibrium,
$$
\begin{gathered}
k=q \\
\left.\Delta G^{\circ}=0 \quad \text { \{for standard states }\right\}
\end{gathered}
$$
So, equilibrium constant
$$
k=1 .
$$

Topic: Chemistry, Thermodynamics (C), AP EAMCET, AP EAMCET 2021 (23 Aug Shift 1)
When secondary growth in thickness is initiated in a dicot root, which of the following happens first?

Options:
A Anticlinal division occurs so that cambium becomes circular
B Parenchyma between xylem and phloem becomes meristematic
C Cambium initial between xylem and phloem divides
D Pericycle strands outside primary xylem divide

The correct answer is:
Parenchyma between xylem and phloem becomes meristematic

Solution:
When secondary growth in thickness is initiated in a dicot root, parenchyma between xylem and phloem becomes meristematic.
Vascular bundles in dicot root are radial, exarch and mostly triarch Vascular cambium is formed from conjunctive parenchyma cells lying just below each phloem strand. Thus the number of cambium strips formed equals the number of phloem strands. The cells of pericycle lying outside the protoxylem also become meristematic to form part of strips of cambium. These-cambial strips join the first formed cambium strips to form complete but wavy ring of vascular cambium. This cambium ring produces secondary xylem on inner-side and secondary phloem on outer side. In roots, the growth rings are not distinct, because there is no seasonal variation under the soil. From the outer layers of pericycle arises the phellogen which cuts phellem (cork) or the outer side and secondary cortex or phelloderm toward the inner side.

Topic: Biology, Anatomy of Flowering Plants, NEET
When success is not an impossible event, then the mean of Binomial distribution is

Options:
A always more than its variance
B always equal to its variance
C always less than its variance
D always equal to its standard deviation

The correct answer is:
always more than its variance

Solution:
When success is not an impossible event, then $p \neq 0, q \neq 0$.
Mean $=n p$ and variance $=n p q$
$$
\begin{aligned}
& p, q < 1 \\
& p>p q \\
& n p>n p q
\end{aligned}
$$
Mean > Variance
$\therefore$ Mean is greater than variance.

Topic: Mathematics, Probability, AP EAMCET, AP EAMCET 2022 (06 Jul Shift 2)
When tension 'T' is applied to a sonometer wire of length $\ell^{\prime}$, it vibrates with the fundamental frequency 'n'. Keeping the experimental setup same, when the tension is increased by 8 newton, the fundamental frequency becomes three times the earlier fundamental frequency (n). The initial tension applied to the wire in newton, was

Options:
A 2.0
B 0.5
C 1.0
D 2.5

The correct answer is:
1.0

Solution:
(C)
$\mathrm{n}=\frac{1}{2 \ell} \sqrt{\frac{\mathrm{T}}{\mathrm{m}}}$
$3 \mathrm{n}=\frac{1}{2 \ell} \sqrt{\frac{\mathrm{T}+8}{\mathrm{~m}}}$
$\therefore \frac{\mathrm{n}}{3 \mathrm{n}}=\sqrt{\frac{\mathrm{T}}{\mathrm{T}+8}}$
$\frac{\mathrm{n}^{2}}{9 \mathrm{n}^{2}}=\frac{\mathrm{T}}{\mathrm{T}+8}$
$\therefore \mathrm{T}+8=9 \mathrm{~T} \Rightarrow 8 \mathrm{~T}=8 \mathrm{~N}$
$\therefore 1 \mathrm{~N}$

Topic: Physics, Waves and Sound, MHT CET, MHT CET 2020 (16 Oct Shift 2)
When tension ' $\mathrm{T}$ ' is applied to a sonometer wire of length ' $\mathrm{l}$ ' it vibrates with the fundamental frequency ' $n$ '. Keeping the setup same, when the tension is increased by $8 \mathrm{~N}$, the fundamental frequency becomes three times the earlier. The initial tension applied to the wire was

Options:
A $2 \mathrm{~N}$
B $0.5 \mathrm{~N}$
C $0.5 \mathrm{~N}$
D $4 N$

The correct answer is:
$0.5 \mathrm{~N}$

Solution:
The initial fundamental frequency of wire can be written as,
On dividing equation ( 2 ) by equation (1), we get
$\begin{aligned} & 3=\sqrt{\frac{T+8 N}{T}} \\ & \Rightarrow 9 T=T+8 N \\ & \Rightarrow T=1 N\end{aligned}$

Topic: Physics, Waves and Sound, MHT CET, MHT CET 2022 (05 Aug Shift 2)
When two cylinders A and B of equal capacity are connected to each other via a stopcock, with A containing a gas at standard temperature and pressure while B is completely evacuated, and the entire system is thermally insulated, what happens to the intermediate states of the system (before settling to the final equilibrium state) in terms of their location on the P-V-T surface?

Options:
A Yes, they lie on the P-V-T surface.
B No, they do not lie on the P-V-T surface.
C Yes, but only momentarily.
D No, but they return to an equilibrium state eventually.

The correct answer is:
No, they do not lie on the P-V-T surface.

Solution:
Correct Option is : (B)
No, they do not lie on the P-V-T surface.

Topic: Chemistry, Thermodynamics, NEET
When vapours of a primary or secondary alcohol are passed over heated copper at 573 K, what reaction takes place?

Options:
A Dehydration
B Oxidation to carboxylic acids
C Oxidation to ketones
D Dehydrogenation to form aldehydes or ketones

The correct answer is:
Dehydrogenation to form aldehydes or ketones

Solution:
When vapours of a primary or secondary alcohol are passed over heated copper at 573 K, dehydrogenation takes place to form aldehydes or ketones.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
When vapours of a secondary alcohol is passed over heated copper at $573 \mathrm{~K}$, the product formed is

Options:
A a carboxylic acid
B an aldehyde
C a ketone
D an alkene

The correct answer is:
a ketone

Solution:
When vapours of alcohols are passed over heated copper at $573 \mathrm{~K}$, primary and secondary alcohols undergo dehydrogenation to give aldehydes and ketones, respectively. While tertiary alcohols undergo dehydration to give alkenes.
Thus, option (3) is correct.

Topic: Chemistry, Aldehydes and Ketones, NEET, NEET 2019 (Odisha)
When we peel the skin of a potato tuber, we remove

Options:
A
periderm

B
epidermis

C
cuticle

D
sapwood

The correct answer is:
periderm

Solution:
Periderm is a tissue of secondary origin that replaces damaged epidermis. It can be found in underground plant organs. In potato, a model for periderm studies, periderm replaces the epidermis early in tuber development and suberized phellems constitute tuber's skin. Thus when we peel off a potato tuber we will remove periderm.

Topic: Biology, Anatomy of Flowering Plants
Where can beehives be kept?

Options:
A In a forest
B In a crop field
C In one’s courtyard or on the verandah of the house or even on the roof
D In a lake

The correct answer is:
In one’s courtyard or on the verandah of the house or even on the roof

Solution:
Beehives can be kept in one’s courtyard, on the verandah of the house or even on the roof.

Topic: Biology, Strategies for Enhancement in Food Production, NEET
Where do the curves intersect?
Consider the curves $\mathrm{f}(\mathrm{x})=\mathrm{x}|\mathrm{x}|-1$ and $\mathrm{g}(\mathrm{x})=\left\{\begin{array}{ll}\frac{3 \mathrm{x}}{2}, & \mathrm{x}>0 \\ 2 \mathrm{x}, & \mathrm{x} \leq 0\end{array} \quad[2016-\mathrm{I}]\right.$

Options:
A $\operatorname{At}(2,3)$ only
B At $(-1,-2)$ only
C At $(2,3)$ and $(-1,-2)$
D Neither at $(2,3)$ nor at $(-1,-2)$

The correct answer is:
At $(2,3)$ and $(-1,-2)$

Solution:
$f(x)=x|x|-1$
$$
f(x)=\left\{\begin{array}{cc}
x^{2}-1 & x>0 \\
-x^{2}-1 & x \leq 0
\end{array} \quad g(x)=\left\{\begin{array}{cc}
\frac{3 x}{2} & x>0 \\
2 x & x \leq 0
\end{array}\right.\right.
$$
Hence $f(x)$ and $g(x)$ intersects at $(-1,-2)$ and $(2,3)$.

Topic: Mathematics, Functions, NDA, NDA 2016 (Phase 1)
Where does the initiation of lateral roots and vascular cambium take place during secondary growth?

Options:
A In epiblema
B In endodermis
C In pericycle
D In pith

The correct answer is:
In pericycle

Solution:
The initiation of lateral roots and vascular cambium during secondary growth takes place in the cells of pericycle.

Topic: Biology, Anatomy of Flowering Plants, NEET
Where is the effluent from the secondary treatment plant generally released?

Options:
A Settling tank
B Aeration tank
C Anaerobic sludge digesters
D Natural water bodies like rivers and streams

The correct answer is:
Natural water bodies like rivers and streams

Solution:
The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.

Topic: Biology, Microbes in Human Welfare, NEET
Which alcohol class reacts most slowly with Lucas reagent in the Lucas test?

Options:
A Primary alcohols
B Secondary alcohols
C Tertiary alcohols
D Aromatic alcohols

The correct answer is:
Primary alcohols

Solution:
Primary alcohols react most slowly with Lucas reagent in the Lucas test.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Which alkali metal has the highest reducing power?

Options:
A Sodium (Na)
B Potassium (K)
C Lithium (Li)
D Rubidium (Rb)

The correct answer is:
Lithium (Li)

Solution:
Among the alkali metals, lithium (Li) has the highest reducing power. This is primarily due to its small ion size, which results in the highest hydration enthalpy and the most negative standard electrode potential (Eo) among alkali metals, making it the strongest reducing agent.

Topic: Chemistry, s Block Elements, NEET
Which α -amino acid does not contain primary amino group?

Options:
A Proline
B Threonine
C Lysine
D All of these

The correct answer is:
Proline

Solution:
Proline contains secondary amino group.

Topic: Chemistry, Biomolecules, NEET
Which among following compounds is a secondary amine?

Options:
A hexane-1,6-diamine
B N,N-Dimethylbenzenamine
C N-methylbenzenamine
D Prop-2-en-1 amine

The correct answer is:
N-methylbenzenamine

Solution:

Topic: Chemistry, General Organic Chemistry, MHT CET, MHT CET 2021 (24 Sep Shift 1)
Which among following statements is NOT true according to principles of green chemistry?

Options:
A In a chemical synthesis the waste product should be zero or minimum.
B Good atom economy means very few atoms of reactants are incorporated in the product.
C Only small amounts of unwanted by products are formed.
D Use of lindane is better than DDT.

The correct answer is:
Good atom economy means very few atoms of reactants are incorporated in the product.

Solution:
Good atom economy means most of the atoms of the reactants are incorporated in the desired products and only small amounts of unwanted byproducts are formed and hence lesser problems of waste disposal.

Topic: Chemistry, Environmental Chemistry, MHT CET, MHT CET 2023 (10 May Shift 1)
Which among the following decreasing order of boiling points is correct for amines?

Options:
A Ethyl dimethylamine $>$ Diethylamine $>$ n-Butylamine
B Diethylamine $>$ Ethyl dimethylamine $>$ n-Butylamine
C n-Butylamine $>$ Ethyl dimethylamine $>$ Diethylamine
D n-Butylamine $>$ Diethylamine $>$ Ethyl dimethylamine

The correct answer is:
n-Butylamine $>$ Diethylamine $>$ Ethyl dimethylamine

Solution:
The order of boiling point of amines is as follows: Primary $>$ Secondary $>$ Tertiary

Topic: Chemistry, Amines, MHT CET, MHT CET 2020 (13 Oct Shift 1)
Which among the following has 23 chromosomes?

Options:
A
Spermatogonia

B
Zygote

C
Secondary oocyte

D
Oogonia

The correct answer is:
Secondary oocyte

Solution:
Secondary oocyte is a product of meiotic division of primary oocyte during oogenesis in the ovary and has 23 chromosomes. Oogenesis is initiated at the foetal ovary in the early embryonic stage of female and a fixed number of oogonia (gamete mother cells) are formed and before the birth of the female child no more oogonia are added after birth.
Spermatogonia is the immature male germ cells that produce sperms. Each spermatogonium is diploid (2n) that contain 46 chromosomes.
The sperms containing haploid nucleus and that of the ovum fuse together to form a diploid $(2 n)$ zygote i.e., 46 chromosomes.
During foetal development, certain cells in the germinal epithelium of the ovary undergo mitotic divisions, producing undifferentiated germ cells called oogonia. The oogonia is diploid ( $2 n)$ and contain 46 chromosomes.

Topic: Biology, Human Reproduction
Which among the following is allylic secondary alcohol?

Options:
A But-2-en-1-ol
B But-3-en-2-ol
C 2 -Methyl but-3-en-2-ol
D Prop-2-en-1-ol

The correct answer is:
But-3-en-2-ol

Solution:
"An allylic alcohol in which the carbon atom that links the double bond to the hydroxy group is also attached to one other carbon and one hydrogen.
A secondary alcohol is a compound in which a hydroxy group, â€’OH, is attached to a saturated carbon atom which has two other carbon atoms attached to it."

Topic: Chemistry, General Organic Chemistry, MHT CET, MHT CET 2020 (14 Oct Shift 2)
Which among the following is most reactive via $\mathrm{S}_{\mathrm{N}} 2$ mechanism

Options:
A
B
C
D

The correct answer is:

Solution:
$\mathrm{Br}$ attached to secondary carbon undergoes steric hindrance in order to occur $\mathrm{S}_{\mathrm{N}} 2$ reaction.

Topic: Chemistry, Haloalkanes and Haloarenes, AP EAMCET, AP EAMCET 2022 (08 Jul Shift 1)
Which among the following is most stable carbocation

Options:
A iso-propyl
B Triphenylmethyl cation
C Ethyl cation
D t-Butyl cation

The correct answer is:
Triphenylmethyl cation

Solution:
Stability of carbonium ions.
tertiary alkyl > secondary alkyl > primary alkyl > methyl.
More the number of alkyl groups, the greater the dispersal of positive charge and therefore, more the stability of carbonium ion is observed.

Dispersal of positive charge increases with the increase in the number of benzene ring.

Topic: Chemistry, General Organic Chemistry, NEET
Which among the following reagents is used to distinguish primary, secondary and tertiary amines according to solubility in alkaline medium?

Options:
A Benzene sulphonyl chloride
B Ethylene glycol
C Iodoform
D Acetyl chloride

The correct answer is:
Benzene sulphonyl chloride

Solution:
Hinsberg reagent: Benzenesulfonyl chloride $\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{SO}_2 \mathrm{Cl}\right)$

Topic: Chemistry, Amines, MHT CET, MHT CET 2022 (06 Aug Shift 2)
Which among the following secondary metabolites is a lectin?

Options:
A Morphine
B Monoterpene
C Concanavalin A
D Curcumin

The correct answer is:
Concanavalin A

Solution:
Metabolites are substances requires for metabolism. These can be primary or secondary. Primary metabolites are those that are needed for normal growth and functions in our bodies. These are amino acids, lipids carbohydrates, etc. Secondary metabolites are those that are not directly involved in growth or any other function of the body. These are morphine, cellulose, ricin, rubber, vinblastin, codeine, concanavalin etc. Morphine are alkaloids. Cellulose is a polymer and ricin is a toxin. Vinblastin is a drug and concanavalin A is a lectin.

Topic: Chemistry, Biomolecules, NEET
Which among the following statements is TRUE about gammexane?

Options:
A It is an isomer of $\mathrm{BHC}$.
B It is one of the herbicides.
C It is obtained from benzene by bromination.
D It is monochloro derivative of benzene.

The correct answer is:
It is an isomer of $\mathrm{BHC}$.

Solution:
The $\gamma$-isomer of benzene hexachloride (BHC), which is used as insecticide, is called as gammexane or lindane.

Topic: Chemistry, Hydrocarbons, MHT CET, MHT CET 2023 (11 May Shift 1)
Which among the following statements of group-1 elements is NOT true?

Options:
A Unipositive ions have inert gas configuration.
B Compounds of unipositive ions are paramagnetic.
C These form colourless compounds in +1 state.
D These have high negative values of standard reduction potential.

The correct answer is:
Compounds of unipositive ions are paramagnetic.

Solution:
Std.11|Ch-8|Subtopic-8.2

Topic: Chemistry, s Block Elements, MHT CET, MHT CET 2023 (10 May Shift 1)
Which among the following will not liberate nitrogen on reaction with nitrous acid?

Options:
A dimethylamine
B 2-aminopropane
C ethylamine
D methylamine

The correct answer is:
dimethylamine

Solution:
Only aliphatic primary amines can react with nitrous acid to produce alcohol, water and nitrogen gas.
$$
\underset{\text { 1-amine }}{R-\mathrm{NH}_2}+\mathrm{HONO} \stackrel{273-278 \mathrm{~K}}{\longrightarrow} \underset{\text { Alcohol }}{\mathrm{R}-\mathrm{OH}}+\mathrm{N}_2+\mathrm{H}_2 \mathrm{O}
$$
So, dimethylamine which is a secondary amine cannot liberate $\mathrm{N}_2$ with HONO.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), COMEDK, COMEDK 2022
Which amongst the following is the most stable carbocation?

Options:
A

B

C

D

The correct answer is:

Solution:
Tertiary carbocations are stable due to $+\mathrm{I}$ effect of alkyl groups and hyperconjugation. Tertiary carbocation has greater number of alpha $\mathrm{H}$ in comparison to secondary carbocation. This increases hyperconjugation which results to its greater stability.
Related Theory
A carbocation will be destabilized by an electron withdrawing group.

Topic: Chemistry, General Organic Chemistry, NEET, NEET 2005
Which cell will measure standard electrode potential of copper electrode?

Options:
A $\mathrm{Pt}_{(s)}\left|\mathrm{H}_{2(\mathrm{~g}, 0.1 \mathrm{bar})}\right| \mathrm{H}_{(a q,, 1 \mathrm{M})}^{+}|| \mathrm{Cu}_{(a q ., 1 \mathrm{M})}^{2+} \mid \mathrm{Cu}_{(s)}$
B $\mathrm{Pt}_{(s)}\left|\mathrm{H}_{2(g, 1 \text { bar })}\right| \mathrm{H}_{(a q, 1,1 \mathrm{M})}^{+}|| \mathrm{Cu}_{(a q,, 2 \mathrm{M})}^{2+} \mid \mathrm{Cu}_{(s)}$
C $\mathrm{Pt}_{(s)}\left|\mathrm{H}_{2(g, 1 \mathrm{bar})}\right| \mathrm{H}_{(a q ., 1 \mathrm{M})}^{+} \| \mathrm{Cu}_{(a q ., 1 \mathrm{M})}^{2+} \mid \mathrm{Cu}_{(s)}$
D $\mathrm{Pt}_{(s)}\left|\mathrm{H}_{2(g, 1 \mathrm{bar})}\right| \mathrm{H}_{(a q, 0.1 \mathrm{M})}^{+} \| \mathrm{Cu}_{(a q ., 1 \mathrm{M})}^{2+} \mid \mathrm{Cu}_{(s)}$

The correct answer is:
$\mathrm{Pt}_{(s)}\left|\mathrm{H}_{2(g, 1 \mathrm{bar})}\right| \mathrm{H}_{(a q ., 1 \mathrm{M})}^{+} \| \mathrm{Cu}_{(a q ., 1 \mathrm{M})}^{2+} \mid \mathrm{Cu}_{(s)}$

Solution:
To calculate the standard electrode potential of the given cell it is coupled with the standard hydrogen electrode in which pressure of hydrogen gas is one bar and the conc. of $\mathrm{H}^{+}$ion in the solution is one molar and also the concentrations of the oxidised and the reduced forms of the species in the right hand half-cell are unity.

Topic: Chemistry, Electrochemistry, AIIMS, AIIMS 2014
Which complex cannot ionise in solution?

Options:
A $\left[\mathrm{CoCl}_{3}\left(\mathrm{NH}_{3}\right)_{3}\right]$
B $\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$
C $\mathrm{K}_{2}\left[\mathrm{Pt}\left(\mathrm{F}_{6}\right)\right]$
D $\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{6}\right] \mathrm{Cl}_{4}$

The correct answer is:
$\left[\mathrm{CoCl}_{3}\left(\mathrm{NH}_{3}\right)_{3}\right]$

Solution:
$\left[\mathrm{CoCl}_{3}\left(\mathrm{NH}_{3}\right)_{3}\right]$ cannot ionise in solution because three chloride ions satisfy primary and secondary valencies. It will not be precipitated by the addition of $\mathrm{AgNO}_{3}$.

Topic: Chemistry, Coordination Compounds, KCET, KCET 2007
Which condition among the following holds true at the state of half-completion for the reaction $A \rightleftharpoons B$ ?

Options:
A $\Delta G^{\circ}=0$
B $\Delta G^{\circ}>0$
C $\Delta G^{\circ} < 0$
D $\Delta G^{\circ}=-R T \ln 2$

The correct answer is:
$\Delta G^{\circ}=0$

Solution:
Equilibrium condition in the course of a reversible chemical reaction is in which no net change in the amounts of reactants and products occurs.
At equilibrium, the reaction is half completed, $[A]=[B]$
Thus, $\frac{[B]}{[A]}=1$
According to standard free Gibbs energy,
$$
\begin{aligned}
\Delta G^{\circ} & =-R T \ln K \\
\Delta G^{\circ} & =-R T \ln (1) \\
{\left[\Delta G^{\circ}\right.} & =0]
\end{aligned}
$$
Hence, at equilibrium condition, the reaction is half-completed i.e., $A \rightleftharpoons B$.

Topic: Chemistry, Electrochemistry, AP EAMCET, AP EAMCET 2021 (25 Aug Shift 1)
Which does not give a precipitate with \(\mathrm{AgNO}_3\) solution?

Options:
A \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_3\)
B \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}\right] \mathrm{Cl}_2\)
C \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right] \mathrm{Cl}\)
D \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right]\)

The correct answer is:
\(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right]\)

Solution:
\(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_3 \mathrm{Cl}_3\right]\) does not give a precipitate with \(\mathrm{AgNO}_3\) solution because in it all the chlorine atoms are attached by secondary valencies.

Topic: Chemistry, Coordination Compounds, JIPMER, JIPMER 2008
Which element from following has highest negative standard reduction potential?

Options:
A K
B Li
C Na
D Rb

The correct answer is:
Li

Solution:
Theory based

Topic: Chemistry, Electrochemistry, MHT CET, MHT CET 2022 (05 Aug Shift 2)