datavorous/entrance-exam-dataset huggingface dataset:
Which one of the following types organisms occupy more than one trophic level in a pond ecosystem ?

Options:
A Frog
B Phytoplankton
C Fish
D Zooplankton

The correct answer is:
Fish

Solution:
No Solution Available

Topic: Biology, Ecosystem, NEET, NEET 2009 (Mains)
Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?

Options:
A Cu2Cl2
B ZnCl2
C CuCl2
D AgCl

The correct answer is:
CuCl2

Solution:
CuCl2 dissolve in water & give blue coloured solutions

CuCl2 + nH2O → Cu2+ (aq)

AgCl not soluble in water.
Cu2Cl2 is not soluble in water.
ZnCl2 is soluble but colourless.

ZnCl2 + nH2O → Zn2+ ( aq ) colourless

Topic: Chemistry, d and f Block Elements, JEE Main, JEE Main 2021 (26 Aug Shift 1)
Which one of the following will be the output of the given circuit?

Options:
A NOR Gate
B NAND Gate
C AND Gate
D XOR Gate

The correct answer is:
XOR Gate

Solution:
Output of the above circuit can be obtained as
y=(A⋅B¯)⋅(A+B)

y=(A¯+B¯)⋅(A+B)

y=A¯.B+B¯.A+A.A¯+B.B¯

y=A¯.B+B¯.A+0+0

y=A¯.B+B¯.A, which is XOR gate

Topic: Physics, Semiconductors, JEE Main, JEE Main 2021 (17 Mar Shift 2)
Which one of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?

Options:
A $\mathrm{CH}_3 \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3$
B $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3$
C $\mathrm{CH}_3 \mathrm{OH}$
D $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}$

The correct answer is:
$\mathrm{CH}_3 \mathrm{OH}$

Solution:
The carbonyl compounds which contains the $\mathrm{CH}_3 \mathrm{CO}-$ or the $\mathrm{CH}_3 \mathrm{C}(\mathrm{H})$ $(\mathrm{OH})$-compounds undergo the iodoform reaction. Benzyl alcohol, Methanol, Diethyl ketone, acetic acid do not give iodoform test.
Caution
Compounds that give positive Iodoform Test are Acetaldehyde, Methyl Ketone, Ethanol, Secondary Alcohols that contain methyl groups in alpha position.

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which one of the following will not give alkyl cyanide on treatment with P2O5

Options:
A
B C6H5-CH=NOH
C
D A and C

The correct answer is:
A and C

Solution:

Topic: Chemistry, Amines, JEE Main
Which one of the following will not show geometrical isomerism

Options:
A $\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2\right] \mathrm{Cl}$
B $\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right] \mathrm{Cl}$
C $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{NO}_2\right] \mathrm{Cl}_2$
D $\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$

The correct answer is:
$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{NO}_2\right] \mathrm{Cl}_2$

Solution:
$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{NO}_2\right] \mathrm{Cl}_2$ will not show geometrical isomerism because this complex showed 4 and 6 co-ordination number.

Topic: Chemistry, Coordination Compounds, JEE Main
Which one of the following will produce a primary alcohol by reacting with $\mathrm{CH}_3 \mathrm{Mgl}$

Options:
A Acetone
B Methyl cyanide
C Ethylene oxide
D Ethyl acetate

The correct answer is:
Ethylene oxide

Solution:
Grignard reagent \(\mathrm{CH}_3 \mathrm{MgI}\) will form a primary alcohol only when it reacts with Formaldehyde (HCHO). Thus, the correct answer is (HCHO).

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which one of the following will react most vigorously with water?

Options:
A
$\mathrm{Li}$

B
$\mathrm{K}$

C
$\mathrm{Rb}$

D
$\mathrm{Na}$

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

Solution:
Reactivity with water increases on moving down the Goup from $\mathrm{Li}$ to $\mathrm{Cs}$ as $\mathrm{Li} < \mathrm{Na}$ $ < \mathrm{K} < \mathrm{Rb} < \mathrm{Cs}$. This is due to increase in electropositive character. Hence Rb reacts most vigorously with water.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2012 (19 May Online)
Which one of the following will show geometrical isomerism?

Options:
A
B
C
D

The correct answer is:

Solution:
Geometrical Isomerism arises due to different arrangement atoms/groups around a system where free rotation of bonds is restricted.

Generally in a geometric isomer, the atoms are bonded by a double bond that does not freely rotate, but it can also happens because of the ring structure.

The other condition to exhibit geometrical isomerism is, two atoms or groups attached to the molecule with the doubly bonded carbon atom must be different. However, it doesn't matter whether the left side groups are the same or different on the right side.

This compound shows geometrical isomerism.

Hence option B is the answer,

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2024 (29 Jan Shift 2)
Which one of the following will undergo meta substitution on monochlorination

Options:
A Ethoxy ethane
B Chlorobenzene
C Ethyl benzoate
D Phenol

The correct answer is:
Ethyl benzoate

Solution:
$-\mathrm{COOH}$ group is meta directing group hence, ethyl benzoate undergo meta substitution.

Topic: Chemistry, Hydrocarbons, JEE Main
Which one of the following work best to carry out the reaction?

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Hydrocarbons, JEE Main
Which one of the following would produce maximum elevation in boiling point

Options:
A $\quad 0.1 \mathrm{M}$ glucose
B $\quad 0.2 \mathrm{M}$ sucrose
C $0.1 \mathrm{M}$ barium chloride
D $\quad 0.1 \mathrm{M}$ magnesium sulphate

The correct answer is:
$0.1 \mathrm{M}$ barium chloride

Solution:
$\mathrm{BaCl}_2$ gives maximum ion. Hence, its boiling point is maximum.

Topic: Chemistry, Solutions, JEE Main
Which one of the followings has maximum number of atoms?

Options:
A 1 g of Mgs [Atomic mass of Mg=24]
B 1 g of O2g [Atomic mass of O=16]
C 1 g of Lis [Atomic mass of Li=7]
D 1 g of Ags [Atomic mass of Ag=108]

The correct answer is:
1 g of Lis [Atomic mass of Li=7]

Solution:
Number of atoms =w molar mass ×NA×atomicity

Number of atoms in 1g of Lis = 17×NA×1

Number of atoms 1g of Ags =1108×NA×1

Number of atoms 1g of Mgs = 124×NA×1

Number of atoms 1g of O2g = 132×NA×2

Topic: Chemistry, Some Basic Concepts of Chemistry, JEE Main
Which one of the given radiations is the least penetrating?

Options:
A Alpha rays
B Beta rays
C Gamma rays
D $\mathrm{X}$-rays

The correct answer is:
Alpha rays

Solution:
Alpha particles have the highest mass out of all of the ionizing radiations. The high mass makes the alpha particles most ionizing. However due to the large mass, the penetration of the alpha particles is the least (only a few $\mathrm{cm}$ through the air) among other ionizing radiations.

Topic: Physics, Nuclear Physics, JEE Main
Which one of the lanthanoids given below is the most stable in divalent form?

Options:
A Yb (Atomic Number 70)
B Sm (Atomic Number 62)
C Eu (Atomic Number 63)
D Ce (Atomic Number 58)

The correct answer is:
Eu (Atomic Number 63)

Solution:
Ce+2:xe4f2

Eu+2:xe4f7

Sm+2:xe4f6

Yb+2:xe4f14

As Yb+2 and Eu+2 has completely filled and half filled 4f orbital, so they would be the most stable. But among the these two Eu+2 is more stable based on reduction potential value.

EM3+/M2+°⇒EuYb-0.35-1.05

Hence, due to more reduction potential in Eu as compared to Yb, it can concluded that Eu2+ is more stable than Yb2+.

Topic: Chemistry, d and f Block Elements, JEE Main, JEE Main 2022 (28 Jun Shift 1)
Which one of the PGRs would be used by farmers if they are asked to?

a Induce parthenocarpy in tomatoes

b Hastens fruit ripening in tomatoes and apples

c Induces flowering in mango

d Elongation and improvement in the shape of the apple

e Promote nutrient mobilization

Options:
A a-auxins, b-ethephon, c-ethylene, d-GA, e- cytokinin
B a-ethylene, b-GA, c-auxin, d - ethephon, e- cytokinin
C a-auxin, b-ethephon, c-cytokinin, d-ethylene, e-GA
D a-cytokinin, b-auxin, c-GA, d-ethephon, e- ethylene

The correct answer is:
a-auxins, b-ethephon, c-ethylene, d-GA, e- cytokinin

Solution:
Plant growth hormones are the signalling molecules that are produced in the plants in low concentrations. Parthenocarpy is the production of fruit artificially or naturally without fertilization of ovules.
Auxin is a plant hormone which when sprayed on the flowers of tomato induces parthenocarpy.
Ethephon is a plant growth regulator used for promotion of fruit ripening, abscission and to induce flowering in plants. Ethylene is the gaseous phytohormone responsible to induce flowering in mango plants as it is involved in the growth and senescence of leaves. GA is the gibberellic acid which is mainly involved in plant growth and development and therefore it is used for elongation and improvement in the shape of apple in plants. Cytokinin is a plant hormone primarily used to promote cell division, to overcome apical dominance and they also promote nutrient mobilization in addition to the formation of new leaves and chloroplast.

Topic: Biology, Plant - Growth and Development, NEET
Which one of the sols acts as protective colloid

Options:
A $\mathrm{As}_2 \mathrm{~S}_3$
B Gelatin
C $\mathrm{Au}$
D $\mathrm{Fe}(\mathrm{OH})_3$

The correct answer is:
Gelatin

Solution:
Correct option is 2. Gelatin
Gelatin with lowest gold number, act as best protective colloid.

Topic: Chemistry, Surface Chemistry, JEE Main
Which one of these animals is not a homeotherm?

Options:
A Camelus
B Chelone
C Macropus
D Psittacula

The correct answer is:
Chelone

Solution:
Chelone or marine turtles belong to the Cheloniidae family

This family is typically large marine turtles that are characterized by their common traits such as, having a flat streamlined wide body and rounded shell and almost paddle-like flippers for their forelimbs. They are a part of the class Reptilia. Eg. Green turtle.Reptilians are poikilothermic whose internal temperature varies considerably. It is the opposite of a homeotherm, an animal which maintains thermal homeostasis.

Both Aves and mammals are homeotherms.
Camelus - Arabian camel
Macropus - Eastern grey kangaroo
Both Camelus and Macropus belong to class Mammalia.
Pisttacula - Plum-headed parakeet, belongs to class Aves.

Topic: Biology, Animal Kingdom, NEET, NEET 2018
Which one of these best describes what happens when boric acid is heated?

Options:
A Boric acid decomposes into water and boron oxide.
B Boric acid undergoes sublimation and turns into a gaseous form.
C Boric acid remains unchanged upon heating.
D Boric acid melts and forms a liquid.

The correct answer is:
Boric acid decomposes into water and boron oxide.

Solution:
Correct Option is : (A)
Boric acid decomposes into water and boron oxide.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which one shows the best formation of adduct?

Options:
A OCH32+BF3
B OSiH32+BF3
C OSiH32+BBr3
D OCH32+BBr3

The correct answer is:
OCH32+BBr3

Solution:
In BF3, there is 2p Ï -2p Ï back bonding so its Lewis acidic character is less, similarly in O..SiH32 there is 2p Ï -3d Ï back bonding, so it is a weak Lewis base O(CH3)2 is strong Lewis base and BBr3 is strong Lewis acid so there show the best formation of adduct.
BBr 3 LA â+â O CH 3 2 LB â (CH 3 ) 2 O â BBr 3 Adduct

Topic: Chemistry, Ionic Equilibrium, JEE Main
Which one the following compounds will readily react with dilute \(\mathrm{NaOH}\) ?

Options:
A \(\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}\)
B \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{OH}\)
C \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{OH}\)
D \(\left(\mathrm{CH}_3\right)_3 \mathrm{COH}\)

The correct answer is:
\(\mathrm{C}_6 \mathrm{H}_5 \mathrm{OH}\)

Solution:

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main, JEE Main 2024 (08 Apr Shift 2)
Which one the following does not have $\mathrm{sp}^2$ hybridized carbon?

Options:
A
Acetone

B
Acetamide

C
Acetonitrile

D
Acetic acid

The correct answer is:
Acetonitrile

Solution:
It is having only $\mathrm{sp}^3 \& \mathrm{sp}$ hybridized carbon atom

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one the following does not have $\mathrm{sp}^2$ hybridized carbon?

Options:
A
Acetone

B
Acetamide

C
Acetonitrile

D
Acetic acid

The correct answer is:
Acetonitrile

Solution:
It is having only $\mathrm{sp}^3 \& \mathrm{sp}$ hybridized carbon atom

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main, JEE Main 2004
Which one the following has largest number of isomers?

Options:
A
$\left[\mathrm{Ru}\left(\mathrm{NH}_3\right)_4 \mathrm{Cl}_2^{+}\right]$

B
$\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}$

C
$\left[\operatorname{lr}\left(\mathrm{PR}_3\right)_2 \mathrm{H}(\mathrm{CO})\right]^{2+}$

D
$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}\right]^{2+}$
( $\mathrm{R}$-= alkyl group, en = ethylenediamine)

The correct answer is:
$\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}$

Solution:
No Solution Available

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2004
Which one the following ions has the highest value of ionic radius?

Options:
A
$\mathrm{Li}^{+}$

B
$\mathrm{F}^{-}$

C
$\mathrm{O}^{2-}$

D
$\mathrm{B}^{3+}$

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

Solution:
$\begin{array}{lllll}\mathrm{e} & 2 & 10 & 10 & 2 \\ \mathrm{p} & 3 & 9 & 8 & 5\end{array}$

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2004
Which one the following is most reactive towards electrophilic attack?

Options:
A

B

C

D

The correct answer is:

Solution:
Hydroxy group is most activating group among given options, towards electrophilic attack.

Topic: Chemistry, Hydrocarbons, NEET, NEET 2008 (Mains)
Which one the following sets of ions represents the collection of isoelectronic species?

Options:
A
$\mathrm{K}^{+}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}, \mathrm{Cl}^{-}$

B
$\mathrm{Na}^{+}, \mathrm{Mg}^{2+}, \mathrm{Al}^{3+}, \mathrm{Cl}^{-}$

C
$\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Mg}^{2+}, \mathrm{Sc}^{3+}$

D
$\mathrm{Na}^{+}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}, \mathrm{F}^{-}$

The correct answer is:
$\mathrm{K}^{+}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}, \mathrm{Cl}^{-}$

Solution:
No Solution Available

Topic: Chemistry, Structure of Atom, JEE Main, JEE Main 2004
Which one the following statement regarding helium is incorrect?

Options:
A
It is used to fill gas balloons instead of hydrogen because it is lighter and non inflammable

B
It is used in gas - cooled nuclear reactors

C
It is used to produce and sustain powerful superconducting reagents

D
It is used as cryogenic agent for carrying out experiments at low temperatures

The correct answer is:
It is used to fill gas balloons instead of hydrogen because it is lighter and non inflammable

Solution:
No Solution Available

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main, JEE Main 2004
Which one/ones of the following reactions will yield 2-propanol? Choose the right answer from (I), (II), (III) and (IV)
(I) CH2=CH-CH3+H2OâH+
(II) CH 3 âCHO â (II)H 2 O I â CH 3 MgI
(III) HCHO â II â H 2 O I â C 2 H 5 MgI
(IV) CH2=CH-CH3âNeutral KMnO4

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

The correct answer is:
I and II

Solution:
(I)
(II)
(III)
(IV)

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which option is not matched in correct sequence

Options:
A d5,d3,d1,d4→ increasing magnetic moment
B MO,M2O3,MO2,M2O5→ decreasing basic strength
C Sc, V, Cr, Mn → increasing number of oxidation state
D Co2+,Fe+3,Cr+3,Sc+3→ increasing stability

The correct answer is:
d5,d3,d1,d4→ increasing magnetic moment

Solution:
A. As Increasing order of magnetic moment will be d1,d3,d4,d5 so this one is not correct
B. As the oxidation state of metal increases, acidic strength increases so this one is correctly matched
C. Mn has the highest oxidation state of +7

Topic: Chemistry, d and f Block Elements, JEE Main
Which organization publishes the 'Red Data Book"?

Options:
A IUCN
B UNEP
C WWF
D GEF

The correct answer is:
IUCN

Solution:
The International Union for Conservation of Nature (IUCN) maintains the Red Data Book. It is a public document which is created for recording endangered and rare species of plants, animals, fungi as well as some local subspecies which are present in a particular region. It helps us in providing complete information for rescarch, studies and also for monitoring the programs on rare and endangered species and their habitats.
Related Theory
Red Data Book of India includes the conservation status of animals and plants which are endemic to the Indian subcontinent. The data for this book is provided through surveys which are conducted by the Zoological Survey of India and the Botanical Survey of India under the guidance of the Ministry of Environment, Forest and Climate Change.
! Caution
The red list contains only the names of the endangered species; however, the Red Data Book contains the information about the species that are on the verge of extinction.

Topic: Biology, Biodiversity and its Conservation, NEET, NEET 2013 (Karnataka)
Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning :

Options:
A \(\Lambda_{\mathrm{m}}-\Lambda_{\mathrm{m}}^0+\mathrm{AC}^{\frac{1}{2}}=0\)
B \(\Lambda_m^2 \mathrm{C}-\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}}^{\circ 2}+\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}} \Lambda_{\mathrm{m}}=0\)
C \(\Lambda^2{ }_m \mathrm{C}+\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}}^{\circ 2}-\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}} \Lambda_{\mathrm{m}}^{\circ}=0\)
D \(\Lambda_{\mathrm{m}}-\Lambda_{\mathrm{m}}^{\circ}-\mathrm{AC}^{\frac{1}{2}}=0\)

The correct answer is:
\(\Lambda_m^2 \mathrm{C}-\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}}^{\circ 2}+\mathrm{K}_{\mathrm{a}} \Lambda_{\mathrm{m}} \Lambda_{\mathrm{m}}=0\)

Solution:
$\begin{aligned} & \mathrm{HA}(\mathrm{aq}) \rightleftharpoons \mathrm{H}^{+}(\mathrm{aq})+\mathrm{A}^{-}(\mathrm{aq}) \\ & \mathrm{K}_{\mathrm{a}}=\frac{\alpha^2 \mathrm{C}}{1-\alpha} \\ & \alpha^2 \mathrm{C}+\mathrm{K}_{\mathrm{a}} \alpha-\mathrm{K}_{\mathrm{a}}=0 \\ & \left(\frac{\lambda_{\mathrm{m}}}{\lambda_{\mathrm{m}}^{\infty}}\right)^2 \mathrm{C}+\mathrm{K}_{\mathrm{a}} \frac{\lambda_{\mathrm{m}}}{\lambda_{\mathrm{m}}^{\infty}}-\mathrm{K}_{\mathrm{a}}=0 \\ & \lambda_{\mathrm{m}}^2 \mathrm{C}+\mathrm{K}_{\mathrm{a}} \lambda_{\mathrm{m}} \lambda_{\mathrm{m}}^{\infty}-\mathrm{K}_{\mathrm{a}}\left(\lambda_{\mathrm{m}}^{\infty}\right)^2=0\end{aligned}$

Topic: Chemistry, Electrochemistry, JEE Main, JEE Main 2024 (09 Apr Shift 2)
Which pair from the following will not form an ideal solution

Options:
A $\mathrm{CCl}_4+\mathrm{SiCl}_4$
B $\mathrm{H}_2 \mathrm{O}+\mathrm{C}_4 \mathrm{H}_9 \mathrm{OH}$
C $\mathrm{C}_2 \mathrm{H}_5 \mathrm{Br}+\mathrm{C}_2 \mathrm{H}_5 \mathrm{I}$
D $\mathrm{C}_6 \mathrm{H}_{14}+\mathrm{C}_7 \mathrm{H}_{16}$

The correct answer is:
$\mathrm{H}_2 \mathrm{O}+\mathrm{C}_4 \mathrm{H}_9 \mathrm{OH}$

Solution:
$\mathrm{H}_2 \mathrm{O}$ and $\mathrm{C}_4 \mathrm{H}_9 \mathrm{OH}$ do not form ideal solution because there is hydrogen bonding between $\mathrm{H}_2 \mathrm{O}$ and $\mathrm{C}_4 \mathrm{H}_9 \mathrm{OH}$.

Topic: Chemistry, Solutions, JEE Main
Which pair of elements with the given atomic numbers is expected to have similar properties?

Options:
A
40,72

B
20,36

C
10,28

D
11,12

The correct answer is:
40,72

Solution:
$\mathrm{Zr}(40), \mathrm{Hf}(72)$ have similar properties as they belong to same group and have same valence shell electronic configuration.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main
Which pair of elements with the given atomic numbers is expected to have similar properties?

Options:
A
40,72

B
20,36

C
10,28

D
11,12

The correct answer is:
40,72

Solution:
$\mathrm{Zr}(40), \mathrm{Hf}(72)$ have similar properties as they belong to same group and have same valence shell electronic configuration.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2012 (19 May Online)
Which pair of gases is mainly responsible for greenhouse effect?

Options:
A Ozone and Ammonia
B Oxygen and Nitrogen
C Nitrogen and Sulphur dioxide
D Carbon dioxide and Methane

The correct answer is:
Carbon dioxide and Methane

Solution:
According to the UNFCCC/Kyoto Protocol, currently there are six green house gases, they are carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride, and nitrogen triflouride.

Topic: Biology, Environmental Issues, NEET
Which pair of oxides is acidic in nature?

Options:
A B2O3, CaO
B N2O, BaO
C CaO, SiO2
D B2O3, SiO2

The correct answer is:
B2O3, SiO2

Solution:
An oxide that combines with water to give an acid is termed as an acidic oxide. The oxide that gives a base in water is known as a basic oxide. An amphoteric solution is a substance that can chemically react as either acid or base.

B2O3 and SiO2 both are oxides of non-metal and hence are acidic in nature.

CaO,BaO=Basic NatureB2O3,SiO2=Acidic NatureN2O=Neutral oxide

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2021 (26 Feb Shift 2)
Which pair of oxyacids of phosphorus contains ' $\mathrm{P}-\mathrm{H}$ ' bonds?

Options:
A $\mathrm{H}_3 \mathrm{PO}_4, \mathrm{H}_3 \mathrm{PO}_3$
B $\mathrm{H}_3 \mathrm{PO}_5, \mathrm{H}_4 \mathrm{P}_2 \mathrm{O}_7$
C $\mathrm{H}_3 \mathrm{PO}_3, \mathrm{H}_3 \mathrm{PO}_2$
D $\mathrm{H}_3 \mathrm{PO}_2, \mathrm{HPO}_3$

The correct answer is:
$\mathrm{H}_3 \mathrm{PO}_3, \mathrm{H}_3 \mathrm{PO}_2$

Solution:

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main
Which pair of points lie on the same side of $3 x-8 y-7=0$

Options:
A $(0,-1)$ and $(0,0)$
B $(4,-3)$ and $(0,1)$
C $(-3,-4)$ and $(1,2)$
D $(-1,-1)$ and $(3,7)$

The correct answer is:
$(-1,-1)$ and $(3,7)$

Solution:
$\begin{aligned}
& L_{(-1,-1)}=3(-1)-8(-1)-7 \lt 0 \\
& L_{(3,7)}=3 \times 3-8 \times 7-7 \lt 0
\end{aligned}$
Hence $(-1,-1)$ and $(3,7)$ lie on the same side of line.

Topic: Mathematics, Straight Lines, JEE Main
Which pair of the following chlorides do not impart colour to the flame?

Options:
A BeCl2 and SrCl2
B BeCl2 and MgCl2
C CaCl2 and BaCl2
D MgCl2 and CaCl2

The correct answer is:
BeCl2 and MgCl2

Solution:
Among the alkaline earth metals, the size of beryllium and magnesium metals is very small. Therefore, the electrons in these metals are bounded more strongly and are not excited by the energy of flame to higher energy states. Hence, these metals or their salts do not impart any colour to the flame.

Topic: Chemistry, s Block Elements, JEE Main
Which pair will show common ion effect

Options:
A $\mathrm{BaCl}_2+\mathrm{Ba}\left(\mathrm{NO}_3\right)_2$
B $\mathrm{NaCl}+\mathrm{HCl}$
C $\mathrm{NH}_4 \mathrm{OH}+\mathrm{NH}_4 \mathrm{Cl}$
D $\mathrm{AgCN}+\mathrm{KCN}$

The correct answer is:
$\mathrm{NH}_4 \mathrm{OH}+\mathrm{NH}_4 \mathrm{Cl}$

Solution:

Topic: Chemistry, Ionic Equilibrium, JEE Main
Which pairs of compounds in the following are position isomers?

Options:
A Isobutyl carbinol and s-butyl alcohol
B Isobutyl alcohol and t-butyl alcohol
C Neopentyl alcohol and isopentyl alcohol
D Vinyl alcohol and ethylene glycol

The correct answer is:
Isobutyl alcohol and t-butyl alcohol

Solution:

Topic: Chemistry, General Organic Chemistry, JEE Main
Which part of human brain is concerned with the regulation of body temperature ?

Options:
A Hypothalamus
B Medulla Oblongata
C Cerebellum
D Cerebrum

The correct answer is:
Hypothalamus

Solution:
No Solution Available

Topic: Biology, Neural Control and Coordination, NEET, NEET 2009 (Mains)