datavorous/entrance-exam-dataset huggingface dataset:
When metal X is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl to form compound (C). The compound (A) when heated strongly gives (D), which is used to extract metal. Identify (X), (A), (B), (C), and (D). Write suitable equations to support their identities.

Options:
A X = Zinc (Zn), A = Zinc Hydroxide (Zn(OH)₂), B = Sodium Zincate (Na₂ZnO₂), C = Zinc Chloride (ZnCl₂), D = Zinc Oxide (ZnO)
B X = Aluminium (Al), A = Aluminium Hydroxide (Al(OH)₃), B = Sodium Aluminate (NaAlO₂), C = Aluminium Chloride (AlCl₃), D = Alumina (Al₂O₃)
C X = Calcium (Ca), A = Calcium Hydroxide (Ca(OH)₂), B = Sodium Calciumate (Na₂CaO₂), C = Calcium Chloride (CaCl₂), D = Calcium Oxide (CaO)
D X = Iron (Fe), A = Iron Hydroxide (Fe(OH)₃), B = Sodium Ironate (Na₂FeO₂), C = Iron Chloride (FeCl₃), D = Iron Oxide (Fe₂O₃)

The correct answer is:
X = Aluminium (Al), A = Aluminium Hydroxide (Al(OH)₃), B = Sodium Aluminate (NaAlO₂), C = Aluminium Chloride (AlCl₃), D = Alumina (Al₂O₃)

Solution:
Correct Option is : (B)
X = Aluminium (Al), A = Aluminium Hydroxide (Al(OH)₃), B = Sodium Aluminate (NaAlO₂), C = Aluminium Chloride (AlCl₃), D = Alumina (Al₂O₃)

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When might repeated crystallization become necessary for the purification of compounds?

Options:
A When the compound has a low solubility in the solvent
B When the compound is highly soluble in one solvent and very little soluble in another solvent
C When the compound has a high melting point
D When the compound is in a gaseous state

The correct answer is:
When the compound is highly soluble in one solvent and very little soluble in another solvent

Solution:
Repeated crystallization may become necessary for the purification of compounds when the compound is highly soluble in one solvent and very little soluble in another solvent.

Topic: Chemistry, General Organic Chemistry, NEET
When moist, how does sulphur dioxide behave?

Options:
A As a strong acid
B As a powerful oxidizing agent
C As a reducing agent
D As a catalyst

The correct answer is:
As a reducing agent

Solution:
As a reducing agent

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When molten Zn is cooled to solid state, it assumes HCP structure. Then the number of nearest neighbours of Zn atoms will be

Options:
A 4
B 6
C 8
D 12

The correct answer is:
12

Solution:
Coordination number with HCP type crystal is 12.

Topic: Chemistry, Solid State, NEET
When monochromatic radiation of intensity I falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2I, the number of emitted electrons and their maximum kinetic energy are respectively

Options:
A N and 2T
B 2N and T
C 2N and 2T
D N and T

The correct answer is:
2N and T

Solution:
The number of photoelectrons ejected is directly proportional to the intensity of incident light. Maximum kinetic energy is independent of intensity of incident light but depends upon the frequency of light. Hence, option 2N and T is correct.

Topic: Physics, Dual Nature of Matter, NEET
When NaNO3 is heated in a closed, oxygen is liberated and NaNO2 is is left behind. At equilibrium

Options:
A addition of NaNO2 favours forward reverse reaction
B addition of NaNO2 favours forward reaction
C increasing temperature favours forward reaction
D decreasing pressure favours reverse reaction

The correct answer is:
increasing temperature favours forward reaction

Solution:
NaNO3(s)⇌NaNO2(s)+12O2(g);ΔH=+ve
Also Kp=(PO2)1/2 and thus, addition of NaNO3 or NaNO2 has no effect.

Topic: Chemistry, Chemical Equilibrium, NEET
When NaCl is added to the reaction mixture of an oil and caustic soda, the soap is thrown out because

Options:
A NaCl is an ionic compound
B soap is insoluble in the presence of chloride ions
C the solubility product of NaCl decreases in the presence of soap
D the solubility product of the soap is exceeded due to the increased concentration of Na+ ions

The correct answer is:
the solubility product of the soap is exceeded due to the increased concentration of Na+ ions

Solution:
When NaCl is added to the reaction mixture of an oil and caustic soda, the soap is thrown out because the solubility product of the soap is exceeded due to the increased concentration of Na+ ions.

Topic: Chemistry, Ionic Equilibrium, NEET
When NaCl is doped with 10-5 mol% SrCl2 then what is the number of cationic vacancies per mole of NaCl?

Options:
A 2×10-7NA
B 10-7NA
C 10-5NA
D 10-6NA

The correct answer is:
10-7NA

Solution:
Each molecule of SrCl2 develops a cation vacancy hence number of cation vacancy per mole NaCl
Total number of molecules =n×NA
=10-5100×NA
Where NA=6.023×1023
Total cationic vacancies = total molecules × vacancies created by 1 molecule
=10-5100×NA×1
=10-7NA

Topic: Chemistry, Solid State, NEET
When NaCl is heated with sulphuric acid in the presence of MnO 2 a greenish-yellow gas is liberated. The gas is

Options:
A Cl 2
B NH 3
C N 2
D H2

The correct answer is:
Cl 2

Solution:
Yellowish-green gas of chlorine is evolved when the sodium chloride is heated with concentrated H 2 SO 4 in presence of MnO 2 .
NaCl+ H 2 SO 4 → NaHSO 4 +HCl
MnO 2 +4HCl→ MnCl 2 +2 H 2 O+ Cl 2

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When naming a complex cation, what is the central metal named as?

Options:
A Using the Latin name
B Using a common element name
C Using a chemical symbol
D Using the anionic ligand's name

The correct answer is:
Using a common element name

Solution:
In a complex cation, the central metal is named using a common element name.

Topic: Chemistry, Coordination Compounds, NEET
When NaOH pallets are left-open in air, they acquire a fluid layer around each pallet because

Options:
A They start melting
B They absorb moisture from air
C They absorb CO2 from air
D They react with air to form a liquid compound

The correct answer is:
They absorb moisture from air

Solution:
When NaOH pallets are left-open in air, they acquire a fluid layer around each pallet because they absorb moisture from air due to deliquescent nature of NaOH.

Topic: Chemistry, s Block Elements, NEET
When neutral or faintly alkaline $\mathrm{KMnO}_4$ is treated with potassium iodide, iodide ion is converted into ' $\mathrm{X}$ '. ' $\mathrm{X}$ ' is

Options:
A $\mathrm{I}_2$
B $\mathrm{IO}_4^{-}$
C $\mathrm{IO}_3^{-}$
D $\mathrm{IO}^{-}$

The correct answer is:
$\mathrm{IO}_3^{-}$

Solution:
When neutral or faintly alkaline $\mathrm{KMnO}_4$ is treated with potassium iodide, $\mathrm{KMnO}_4$ is converted into $\mathrm{MnO}_2$ while iodide $\left(\mathrm{I}^{-}\right)$ion is converted inot $\mathrm{IO}_3^{-}$(iodate). The reaction takes place as follows:

Topic: Chemistry, d and f Block Elements, NEET, NEET 2019 (Odisha)
When n-heptane is passed over Al 2 O 3 + Cr 2 O 3 catalyst at 773K the product formed is?

Options:
A Benzene
B Toluene
C Polyheptane
D Cycloheptane

The correct answer is:
Toluene

Solution:

Topic: Chemistry, Hydrocarbons, NEET
When nitrogen dioxide is dissolve in water, the product obtained is

Options:
A Does not dissolve in water
B Dissolves to form 6 acid and gives off oxygen
C Dissolves forming nitric acid
D Dissolves to form a mixture of nitrous and nitric acids

The correct answer is:
Dissolves to form a mixture of nitrous and nitric acids

Solution:
Nitrogen dioxide is dissolve in water to form a mixture of nitrous and nitric acids
2NO2+H2O→HNO3+HNO2

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When one 2s and three 2p-orbitals of carbon hybridise, what type of hybrid orbitals are formed?

Options:
A sp orbitals
B sp2 orbitals
C sp3 orbitals
D sp4 orbitals

The correct answer is:
sp3 orbitals

Solution:
When one 2s and three 2p-orbitals of carbon hybridise, there is the formation of four new sp3 hybrid orbitals.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
When one $\mathrm{CO}_2$ molecule is fixed as one molecule of triose phosphate, which of the following photochemically made, high energy chemical intermediates are used in the reduction phase?

Options:
A 1 ATP +1 NADPH
B 1 ATP +2 NADPH
C $2 \mathrm{ATP}+1 \mathrm{NADPH}$
D 2 ATP +2 NADPH

The correct answer is:
1 ATP +1 NADPH

Solution:
During $\mathrm{C}_3$ cycle (calvin cycle) 3 phases continue, namely carboxylation, Reduction \& regeneration. During reduction or fixation phase, each $\mathrm{CO}_2$ molecule require one mole of ATP and one mole of NADPH.

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2022 (Phase 2)
When one end of the capillary is dipped in water, the height of the water column is h. The upward force of 105 dyne due to surface tension is balanced by the force due to the weight of the water column. The inner circumference of the capillary is
(Surface tension of water =7Ã10-2 N m-1)

Options:
A 1.5 cm
B 2 cm
C 2.5 cm
D 3 cm

The correct answer is:
1.5 cm

Solution:
F=105 dyne=105Ã10-5 N,T=7Ã10-2Nm-1
2ÏrT=F
2Ïr=FT=105Ã10-57Ã10-2
=15Ã10-3m
=1.5Ã10-2m
=1.5 cm

Topic: Physics, Mechanical Properties of Fluids, NEET
When one mole of sulphuric acid react with one mole of zinc dust in a bomb calorimeter, then ΔU and w correspond to

Options:
A ΔU<0, w=0
B ΔU>0, w=0
C ΔU=0, w<0
D ΔU<0, w>0

The correct answer is:
ΔU<0, w=0

Solution:
Bomb calorimeter is commonly used to find the heat of combustion of organic substances which consists of a sealed combustion chamber, called a bomb. If a process is run in a sealed container then no expansion or compression is allowed, so w=0 and ΔU=q .
ΔU<0,w=0

Topic: Chemistry, Thermodynamics (C), NEET
When one molecule of glucose undergoes oxidation in glycolysis, it produces

Options:
A 2 molecules of pyruvic acid
B 1 molecule of pyruvic acid
C 2 molecules of CO2
D 2 molecules of O2

The correct answer is:
2 molecules of pyruvic acid

Solution:
Glucose is a six carbon compound and it undergoes oxidation in glycolysis to form two molecules of six carbon compound called pyruvic acid. Glycolysis occurs in cytoplasm and the most common pathways is EMP pathway.

Topic: Biology, Respiration in Plants, NEET
When one of the following is likely to give a precipitate with AgNO3 soltuion?

Options:
A (CH3)3CCl
B CHCl3
C CH2=CH—Cl
D CCl4

The correct answer is:
(CH3)3CCl

Solution:
As 3° butyl chloride gives most stable carbocation, so the reaction is possible. In rest all very unstable carbocations are formed so the reaction is not possible.

Topic: Chemistry, General Organic Chemistry, NEET
When only the first division is followed by cytokinesis, the development of endosperm is called

Options:
A cellular
B ruminate
C helobial
D nuclear

The correct answer is:
helobial

Solution:
In the helobial type of endosperm development, the endosperm is intermediate between cellular and nuclear types. A helobial endosperm is one in which the first mitotic division is followed by cytokinesis, delimiting two cells. Later, the nucleus of one cell continues with a nuclear type of development and the other cell divides in a cellular fashion.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
When orthoboric acid is heated strongly, it gives

Options:
A B2O3
B H2B4O7
C HBO2
D B

The correct answer is:
B2O3

Solution:
When orthoboric acid is heated strongly, it gives B2O3
H3BO3→HeatHBO2→HeatB2O3

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
When ovules are borne on the central axis and septa are absent as in Dianthus and prime rose the placentation is

Options:
A Axile
B Parietal
C Free central
D Basal.

The correct answer is:
Free central

Solution:
The arrangement of ovules within the ovary on the placenta is called placentation. When the placenta is present in the center and the ovary is unilocular the placentation is called free central.

Topic: Biology, Morphology of Flowering Plants, NEET
When P2O5 is heated with water, it gives

Options:
A Hypophosphorus acid
B Hypophosphoric acid
C Orthophosphoric acid
D Orthophosphorus acid

The correct answer is:
Orthophosphoric acid

Solution:
It is anhydride of orthophosphoric acid, hence on heating with water it gives P2O5+3H2O → 2H3PO4 orthophosphoric acid.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When PbO2 reacts with concentrated HNO3 , the gas evolved is

Options:
A NO2
B O2
C N2
D N2O

The correct answer is:
O2

Solution:
Here O2 is released as follows
2PbO2+4HNO3→2Pb(NO3)2+2H2O+O2↑

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
When p calories of heat is given to a body, it absorbs q calories. Then the absorption power of body will be

Options:
A pq
B qp
C p2q2
D q2p2

The correct answer is:
qp

Solution:
Absorption power =Heat absorbedTotal heat given=qp

Topic: Physics, Thermal Properties of Matter, NEET
When p-n junction diode is forward biased, then

Options:
A the depletion region is reduced and barrier height is increased
B the depletion region is widened and barrier height is reduced
C both the depletion region and barrier height are reduced
D both the depletion region and barrier height are increased

The correct answer is:
both the depletion region and barrier height are reduced

Solution:
When p-n junction diode is forward biased, both the depletion region and barrier height are reduced.

Topic: Physics, Semiconductors, NEET
When passed through heated iron tube, propyne polymerizes to give

Options:
A benzene
B 1,3,5-trimethylbenzene
C toluene
D hexamethylbenzene

The correct answer is:
1,3,5-trimethylbenzene

Solution:
Propyne when passed through heated tube polymerizes to give 1,3, 5-trimethylbenzene (mesitylene)

Topic: Chemistry, Hydrocarbons, NEET
When phenol is heated with phthalic anhydride and H2SO4, it produces

Options:
A Phenol red
B Methyl orange
C Salicylic acid
D Phenolphthalein

The correct answer is:
Phenolphthalein

Solution:
In the presence of conc. H2SO4, two molecules of phenol condense with phthalic anhydride to form phenolphthalein

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
When phenol is treated with bromine water, what product is formed?

Options:
A 2,4,6-tribromophenol
B 2,4-dibromophenol
C Mono Bromophenols
D 4-bromophenol

The correct answer is:
2,4,6-tribromophenol

Solution:
Phenol forms 2,4,6-tribromophenol when treated with bromine water.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
When phenol is treated with bromine water, white precipitate is obtained. Give the IUPAC name of the compound formed.

Options:
A 1,4,6-Tribromophenol
B 2,4,5-Tribromophenol
C 1,2,3-Tribromophenol
D 2,4,6-Tribromophenol

The correct answer is:
2,4,6-Tribromophenol

Solution:
Correct Option is : (D)
2,4,6-Tribromophenol

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
When phenol is treated with $\mathrm{CHCl}_3$ and $\mathrm{NaOH}$, the product formed is:

Options:
A benzaldehyde
B salicylaldehyde
C salicylic acid
D benzoic acid

The correct answer is:
salicylaldehyde

Solution:
When phenol is treated with $\mathrm{CHCl}_3$ and $\mathrm{NaOH}$ the product formed is salicylaldehyde, this reaction is known as Reimer-Tiemann reaction.
In this reaction chloroform first reacts with sodium hydroxide toproduce dichlorocarbene which is the intermediate of this reaction.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET, NEET 2002
When photons of energy hv are incident on the surface of photosensitive material of work function hv0 , then

Options:
A the kinetic energy of all emitted electrons is hv0
B the kinetic energy of all emitted electrons is hv-v0
C the kinetic energy of all fastest electrons is hv-v0
D the kinetic energy of all emitted electrons is hv

The correct answer is:
the kinetic energy of all fastest electrons is hv-v0

Solution:
12mvmax2=hv-hv0
12mvmax2=hv-v0
This is Einstein's equation of photoelectric effect.

Topic: Physics, Dual Nature of Matter, NEET
When photons of energy hv are incident on the surface of photosensitive material of work function hv0, then

Options:
A the kinetic energy of all emitted electrons is hv0
B the kinetic energy of all emitted electrons is hv-v0
C the kinetic energy of all fastest emitted electrons is hv-v0
D the kinetic energy of all emitted electrons is hv

The correct answer is:
the kinetic energy of all fastest emitted electrons is hv-v0

Solution:
12mvmax2=hv-hv0
=hv-v0
This is Einstein's equation of photoelectric effect.

Topic: Physics, Dual Nature of Matter, NEET
When photons of energy $h v$ fall on an aluminium plate (of work function $E_0$ ), photoelectrons of maximum kinetic energy $K$ are ejected. If the frequency of radiation is doubled, the maximum kinetic energy of the ejected photoelectrons will be:

Options:
A $K+h v$
B $K+E_0$
C $2 K$
D $K$

The correct answer is:
$K+h v$

Solution:
According to given situation
$\begin{aligned} & h v & =E_0+K \\ \text { and } & 2 h v & =E_0+k^{\prime} \\ \Rightarrow & k^{\prime} & =k+h v\end{aligned}$

Topic: Physics, Dual Nature of Matter, NEET, NEET 2006
when plaster of Paris comes in contact with water it sets into a hard mass. The composition of the hard mass is

Options:
A CaSO4.H2O
B CaSO4.Ca(OH)2
C CaSO4.2H2O
D CaSO4.2Ca(OH)2

The correct answer is:
CaSO4.2H2O

Solution:
If we mix plaster of Paris (CaSO4.12H2O) with water a hard substance will be formed, gypsum.Plaster of Paris is a slightly soluble solid which reacts exothermically with water to produce gypsum (CaSO4.2H2O) .
2CaSO 4 ⋅ 1 2 H 2 O Plaster of Paris  +  3H 2 O→ 2CaSO 4 ⋅ 2H 2 O Gypsum Hard mass

Topic: Chemistry, s Block Elements, NEET
When pollen grains of a flower pollinate the stigma of another flower of the same plant, it is called:

Options:
A Dichogamy
B Herkogamy
C Geitonogamy
D Autogamy

The correct answer is:
Geitonogamy

Solution:
Geitonogamy is the transfer for pollen grains from anthers of one flower to another flower of either the same plant. It is ecogically a cross pollination but genetically self-pollination.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
When pollen grains of a flower pollinate the stigma of another flower of the same plant, it is called

Options:
A Dichogamy
B Herkogamy
C Geitnogamy
D Autogamy

The correct answer is:
Geitnogamy

Solution:
Geitonogamy is the transfer for pollen grains from anthers of one flower to another flower of either the same plant or genetically similar plant or between two clones.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
When potassium superoxide is dissolved in water, the products obtained are

Options:
A KOH and H2O2
B KOH, H2O2 and O2
C KOH and O2
D KOH, H2O2 and O3

The correct answer is:
KOH, H2O2 and O2

Solution:
When potassium superoxide is dissolved in water, KOH, H2O2 and O2 are formed
2KO2+2H2O→2KOH+H2O2+O2

Topic: Chemistry, s Block Elements, NEET
When pressure is not constant during compression and changes in a series of finite steps, how is the total work done on the gas calculated?

Options:
A By multiplying the final pressure by the change in volume
B By taking the integral of pressure with respect to volume
C By summing the work done at each step over all the steps
D By using the ideal gas law

The correct answer is:
By summing the work done at each step over all the steps

Solution:
When pressure changes in a series of finite steps during compression, the total work done on the gas is calculated by summing the work done at each step over all the steps.

Topic: Chemistry, Thermodynamics (C), NEET
When propionic acid is subjected to reduction with hydroiodic acid and Red phosphorus, the product formed is

Options:
A Butane
B Propane
C Ethane
D None of these

The correct answer is:
Propane

Solution:
CH3-CH2-COOH+6HIâRed PCH3-CH2-CH3Propane+2H2O+3I2

Topic: Chemistry, Carboxylic Acid Derivatives, NEET
When propyne is treated with aqueous H 2 S O 4 in presence of HgS O 4, the major product is â

Options:
A Propanal
B Propyl Hydrogen Sulphate
C Acetone
D Propanol

The correct answer is:
Acetone

Solution:
Alkynes undergo Markownikoffs addition of water in presence of H 2 S O 4 / HgS O 4 :

Topic: Chemistry, Hydrocarbons, NEET
When Q amount of heat is supplied to an ideal monoatomic gas, the gas performs Q2 amount of work on its surrounding, then

Options:
A 2R
B 1.5R
C 3R
D 2.5R

The correct answer is:
3R

Solution:
Q=∆U+W

Q=ΔU+Q2

⇒ΔU=Q2

⇒ ∆U=32nRΔT=Q2

C=Qn∆T

⇒C=3R

Topic: Physics, Thermodynamics, NEET
When radiation is incident on a photoelectron emitter, the stopping potential is found to be 9 V. If e/m for the electron is 1.8Ã1011 C kg-1, the maximum velocity of ejected electrons is

Options:
A 6Ã105 m s-1
B 8Ã105 m s-1
C 106 m s-1
D 1.8Ã106 m s-1

The correct answer is:
1.8Ã106 m s-1

Solution:
eV=12mv2
or v=2eVm=2Ã(1.8Ã1011)Ã9=1.8Ã106 m s-1

Topic: Physics, Dual Nature of Matter, NEET
When reacts with KOH in the presence of water (through SNâ2 reaction mechanism), then the stereochemistry of product so formed will be -

Options:
A R
B S
C Mixture of R and S
D Partial S + racemic mixture

The correct answer is:
S

Solution:
In SN2 inversion takes place.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
When resources are limited, populations exhibit logistic growth. In logistic growth, population expansion decreases as resources become scarce, levelling off when the carrying capacity of the environment is reached, resulting in a __________ curve.

Options:
A S-shaped.
B J-shaped.
C Straight line.
D Circular.

The correct answer is:
S-shaped.

Solution:
Logistic growth: No population of any species in nature has at its disposal unlimited resources to permit exponential growth. This leads to competition between individuals for limited resources. Eventually, the ‘fittest’ individual will survive and reproduce. In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. This limit of nature is called carrying capacity (K) for that species in that habitat. A population growing in a habitat with limited resources show initially a lag phase, followed by phases of acceleration and deceleration and finally an asymptote when the population density reaches the carrying capacity. A plot of N in relation to time (t) results in a sigmoid curve.

Topic: Biology, Organisms and Populations, NEET
When resources in the habitat are un-limited?

Options:
A Population grows in an exponential or geometric fashion
B Impact of natality and mortality becomes zero
C Biotic potential will be minimum
D Population always shows Verhulst pearl-logistic growth

The correct answer is:
Population grows in an exponential or geometric fashion

Solution:
Resources (food and space) availability is obviously essential for the unimpeded growth of a population. Ideally, when resources in the habitat are unlimited, each species has the ability to realize fully its innate potential to grow in number. Then the population grows in an exponential or geometric fashion.

Topic: Biology, Organisms and Populations, NEET
When RNA is hydrolysed, there is no relationship among the quantities of different bases obtained. What does this fact suggest about the structure of RNA?

Options:
A RNA has a highly repetitive structure.
B RNA has a single-stranded structure.
C RNA contains all four bases in equal proportions.
D RNA is a complex base

The correct answer is:
RNA has a single-stranded structure.

Solution:
Correct Option is : (B)
RNA has a single-stranded structure.

Topic: Chemistry, Biomolecules, NEET
When SO2 gas is passed into aqueous Na2CO3, the product(s) formed is (are)

Options:
A NaHSO4
B Na2SO4
C NaHSO3
D Na2SO3 and NaHSO3

The correct answer is:
Na2SO3 and NaHSO3

Solution:
2SO2(g)+Na2CO3(aq)+H2O(l)→2NaHSO3(aq)+CO2(g)→Na2CO3(aq)Na2SO3(aq)+H2O(l)+CO2(g)
Thus, both products NaHSO3 and Na2SO3 are formed when SO2 gas is passed through aqueous Na2CO3 solution.

Topic: Chemistry, s Block Elements, NEET
When SO2 is passed through an aqueous solution of I2 , it becomes colourless. This is due to

Options:
A bleaching reaction of SO2
B formation of HIO 2
C combination of SO2 and I2
D formation of HNO3

The correct answer is:
combination of SO2 and I2

Solution:
When SO2 is passed through an aqueous solution of I2 , it becomes colourless. This is due to combination of SO2 and I2 as follows
SO2+2H2O+I2→H2SO4+2HI

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET