datavorous/entrance-exam-dataset huggingface dataset:
The percentage of all gymnosperm species facing extinction is

Options:
A 12
B 23
C 32
D 31

The correct answer is:
31

Solution:
More than 15,500 species worldwide are facing the threat of extinction. Presently, 12 percent of all bird species, 23 percent of all mammal species, 32 percent of all amphibian species, and 31 percent of all gymnosperm species in the world face the threat of extinction.

Topic: Biology, Biodiversity and its Conservation, NEET
The percentage of C, H and N in an organic compound are 40%, 13.3% and 46.7% respectively then empirical formula is

Options:
A C3H13N3
B CH2N
C CH4N
D CH6N

The correct answer is:
CH4N

Solution:
Element	%	Atomic mass	Relative number of atoms	Simplest ratio of atoms	Element

1.	C	40	12	4012=3.33	3.333.3=1

2.	H	13.3	1	13.31=13.3	13.33.3=4

3.	N	46.7	14	46.714=3.3	3.33.3=1

Therefore, empirical formula is CH4N .

Topic: Chemistry, General Organic Chemistry, NEET
The percentage of $\mathrm{C}, \mathrm{H}$ and $\mathrm{N}$ in an organic compound are $40 \%, 13.3 \%$ and $46.7 \%$, respectively, then the empirical formula is:

Options:
A $\mathrm{C}_3 \mathrm{H}_{13} \mathrm{~N}_3$
B $\mathrm{CH}_2 \mathrm{~N}$
C $\mathrm{CH}_4 \mathrm{~N}$
D $\mathrm{CH}_6 \mathrm{~N}$

The correct answer is:
$\mathrm{CH}_4 \mathrm{~N}$

Solution:
Hence, empirical formula of compound is $\mathrm{CH}_4 \mathrm{~N}$.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET, NEET 2002
The percentage of juxtamedullary nephrons in kidneys is ____.

Options:
A 15%.
B 45%.
C 65%.
D 85%.

The correct answer is:
15%.

Solution:
Juxtamedullary nephrons form about 15% of total nephrons. Their glomeruli are found in the inner margin of the cortex. They control the plasma volume when water supply is short.

Topic: Biology, Excretory Products and their Elimination, NEET
The percentage of lanthanides and iron, respectively, in Misch metal are

Options:
A 50, 50
B 75, 25
C 90, 10
D 95, 5

The correct answer is:
95, 5

Solution:
Misch metal (from German: Misch metall – "mixed metal") is an alloy of rare earth elements. It is also called cerium misch metal, rare earth misch metal or misch metal. A typical composition includes approximately 50% cerium and 25% lanthanum, with small amounts of neodymium and praseodymium.

In misch metal alloy, the percentage of lanthanides iron are 95 and 5 respectively.

Topic: Chemistry, d and f Block Elements, NEET
The percentage of Mg2+ ions in a solution can be tested by adding a solution of

Options:
A NH3
B Na2HPO4
C Na2SO4
D NH4Cl

The correct answer is:
Na2HPO4

Solution:
The percentage of Mg2+ ions in a solution can be tested by adding a solution of Na2HPO4 as follows
Mg2++Na2HPO4+NH4OH+5H2OâMg(NH4)PO4White ppt..6H2Oâ+2Na+

Topic: Chemistry, s Block Elements, NEET
The percentage of nucleic acids present in a cell is

Options:
A 1%
B 5 -7 %
C 2-3 %
D 70-90 %

The correct answer is:
5 -7 %

Solution:
In the cell, water is around 70-90 % . This is followed by proteins 10-15% . Then nucleic acids 5-7% , carbohydrates 3%, lipids 2% and ions around 1%.

Topic: Chemistry, Biomolecules, NEET
The percentage of p-character in the orbitals forming P – P bonds in P4 is

Options:
A 25
B 50
C 33
D 75

The correct answer is:
75

Solution:
P is sp3 hybridised in P4 So p character is 75% in it.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
The percentage of pyridine C5H5N that forms pyridinium ion C5H5N+H in a 0.10 M aqueous pyridine solution Kb for C5H5N=1.7×10-9 is

Options:
A 0.0060%
B 0.013%
C 0.77%
D 1.6%

The correct answer is:
0.013%

Solution:
C5H5N+H2O⇌C5H5N⊕H+OH⊖t=0Ct=eqC1-αCαCα
∴Kb=Cα21-α≈Cα2
∴α=KbC=1.7×10-90.1
= 1.3 × 1 0 - 4
∴% α=1.3×10-4×100=0.013%

Topic: Chemistry, Ionic Equilibrium, NEET, NEET 2016 (Phase 2)
The percentage of Se in peroxides enzyme is 0.5% by mass (atomic mass of Se = 78.4 amu). Then, the minimum molecular mass of enzyme which contains not more than one Se atom is

Options:
A 1.568×104amu
B 1.568×107 amu
C 1.568×103 amu
D 1.568×106 amu

The correct answer is:
1.568×104amu

Solution:
As 0.5 g Se is present in 100 g enzyme
So 78.4 g Se will be present in =1000.5×78.4 w g enzyme
=15680 amu
=1.568×104 amu.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The percentage proportion of homozygous parents in the F2 generation of a monohybrid cross is ______ the percentage proportion of homozygous parents in the F2 generation of a dihybrid cross

Options:
A is same as
B is greater than
C is lesser than
D may be same or greater but never lesser than

The correct answer is:
is greater than

Solution:
In a monohybrid cross, there are two homozygous parents out of total four offsprings. Thus their proportion is 50%. In a dihybrid cross, there are two homozygous parents out of total sixteen offsprings. Thus their proportion is 12.5%

Topic: Biology, Principles of Inheritance and Variation, NEET
The pericardial fluid is a protective fluid found between the two layers of the

Options:
A endocardium
B pericardium
C myocardium
D epicardium

The correct answer is:
pericardium

Solution:
The pericardium is a double-walled structure .About 20â30 ml in volume, this serous fluid acts as a lubricant and minimizes friction between the epicardium and parietal layer as the heart.

Topic: Biology, Body Fluids and Circulation, NEET
The pericardial fluid is present in the

Options:
A Double walled membranous bag
B Double walled cartilaginous cavity
C Double walled coelomic cavity
D Single walled membranous bag

The correct answer is:
Double walled membranous bag

Solution:
The heart is enclosed in a fibrous sac termed the pericardium. The pericardium and its fluid lubricate the moving surfaces of the heart.

Topic: Biology, Body Fluids and Circulation, NEET
The perigynous condition of ovary is present in flowers of:

Options:
A Cucumber
B Cotton
C Guava
D Peach

The correct answer is:
Peach

Solution:
If the gynoecium is situated in the center and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called as perigynous. The ovary here is said to be half inferior as in plum, rose and peach.

Topic: Biology, Morphology of Flowering Plants, NEET
The perigynous flower is observed in:

Options:
A Rose
B Plum
C Pea
D Both (a) and (b)

The correct answer is:
Both (a) and (b)

Solution:
Flowers with half inferior ovary are known as a perigynous flower or If gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous. The ovary here is said to be half inferior, e.g., plum, rose, peach.

Topic: Biology, Morphology of Flowering Plants, NEET
The perigynous ovary will be seen in

Options:
A Peach
B Cucumber
C Cotton
D Guava

The correct answer is:
Peach

Solution:
The flower of the angiosperm plant can be categorized depending on the arrangement of the whorls around the gynoecium.
Epigynous flowers have the ovary is in the inferior position as the thalamus surrounds the ovary and may even fuse with it. The other whorls develop over the thalamus. This arrangement is shown by guava, cucumber and ray florets of sunflower.
If the ovary position is above the thalamus, that is superior to other whorls, the arrangement is called hypogynous. Mustard, brinjal develop such flowers.
When the gynoecium and other whorls are arranged almost at same level, the flower is called perigynous and ovary position is considered half inferior. Peach plant has such type of flower arrangement

Topic: Biology, Morphology of Flowering Plants, NEET
The period from birth to the natural death of an organism represent its

Options:
A Life span
B Life cycle
C Natality
D Mortality

The correct answer is:
Life span

Solution:
Each and every organism can live only for a certain period of time. The period from birth to the natural death of an organism represents its life span. Natality refers to the number of births during a given period in the population that are added to the initial density. Mortality refers to the number of deaths in the population during a given period. The life cycle is the series of changes in the life of an organism including reproduction.

Topic: Biology, Reproduction in Organisms, NEET
The period number and group number of Tantalum (Z = 73) are respectively

Options:
A 5, 7
B 6, 13
C 6, 5
D None of these

The correct answer is:
6, 5

Solution:
The period number and group number of Tantalum (Z = 73) are respectively VI and 5
Electronic configuration of Tantalum → (Xe)4f14,5d3,6s2

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
The period of a simple pendulum inside a stationary lift is T. The lift accelerates upwards with an acceleration of g3. The time period of pendulum will be

Options:
A 2 T
B T2
C 32T
D T3

The correct answer is:
32T

Solution:
When lift accelerates upwards, then effective acceleration on the pendulum
geff=g+g3=4g3
â´ Time period T′=2Ïlgeff=2Ïl4g/3
=32.2Ïlg
=Â 32Â T

Topic: Physics, Oscillations, NEET
The period of a simple pendulum inside a stationary lift is T. The lift accelerates upwards with an acceleration of g/3. The time period of pendulum will be

Options:
A 2 T
B T2
C 32T
D T3

The correct answer is:
32T

Solution:
When lift accelerates upwards, then effective acceleration on the pendulum
geff=g+g3=4g3
â´ Time period T′=2Ïlgeff=2Ïl4g/3
=32.2Ïlg
=Â 32Â T

Topic: Physics, Oscillations, NEET
The period of oscillation of a mass $M$ suspended from a spring of negligible mass is $\mathrm{T}$. If along with it another mass $M$ is also suspended, the period of oscillation will now be

Options:
A $\mathrm{T}$
B $\mathrm{T} / \sqrt{2}$
C $2 \mathrm{~T}$
D $\sqrt{2} \mathrm{~T}$

The correct answer is:
$\sqrt{2} \mathrm{~T}$

Solution:
Time period of spring pendulum, $T=2 \pi \sqrt{\frac{M}{k}}$. If now mass in doubled $\mathrm{T}^{\prime}=2 \pi \sqrt{\frac{2 \mathrm{M}}{\mathrm{k}}}=\sqrt{2} \mathrm{~T}$

Topic: Physics, Oscillations, NEET, NEET 2010 (Screening)
The period of oscillation of a simple pendulum of length L suspended from the roof of a vehicle which moves without friction down an inclined plane of inclination Î± is given by

Options:
A 2πLgcos⁡α
B 2πLgsin⁡α
C 2πLg
D 2πLgtan⁡α

The correct answer is:
2πLgcos⁡α

Solution:
When vehicle is accelerated Fpseudo will act on pendulum which will balance the force along the incline.
FP=mgsinâ¡Î±
Therefore, geff=gcosâ¡Î±.
â´ T=2ÏLgcosâ¡Î±

Topic: Physics, Oscillations, NEET
The period of oscillations of a magnet is 2 s. If it is magnetized such that the pole strength becomes 4 times, then its period will be

Options:
A 4 s
B 1 s
C 2 s
D 12 s

The correct answer is:
1 s

Solution:
When pole strength becomes 4 times, magnetic moment M becomes four times.
As T∝1M
Therefore, T becomes 14=12 times.
∴T=22=1 s

Topic: Physics, Magnetic Properties of Matter, NEET
The period of revolution of an electron in the ground state of a hydrogen atom is T. The period of revolution of the electron in the first excited state is

Options:
A 2 T
B 4Â T
C 6Â T
D 8 T

The correct answer is:
8 T

Solution:
T=2πrv
r∝n2
v∝1n
∴T∝n3
T2T1=2313=8

Topic: Physics, Atomic Physics, NEET
The period of viability in seeds vary from species to species. Which of the following plants has seeds with the highest recorded period of viability?

Options:
A Orobanche uniflora
B Striga asiatica
C Phoenix dactylifera
D Lupinus arcticus

The correct answer is:
Lupinus arcticus

Solution:
There are several records of very old yet viable seeds. The oldest is that of a lupine, Lupinus arcticus, excavated from Arctic Tundra. The seed germinated and flowered after an estimated record of 10,000 years of dormancy. A recent record of 2000-year-old viable seed is of the date palm, Phoenix dactylifera, discovered during the archeological excavation at King Herod’s palace near the Dead Sea.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
The peripheral nervous system is divided into two divisions called A and B. A relays impulses from the CNS to skeletal muscles while the B transmits impulses from the CNS to the involuntary organs and smooth muscles of the body. B is further classified into C and D neural system.

Options:
A

A	B	C	D

Autonomic neural system	Somatic neural system	Sympathetic	Parasympathetic

B

A	B	C	D

Sympathetic	Parasympathetic	Autonomic neural system	Somatic neural system

C

A	B	C	D

Somatic neural system	Autonomic neural system	Sympathetic	Parasympathetic

D

A	B	C	D

Somatic neural system	Sympathetic	Autonomic neural system	Parasympathetic

The correct answer is:

A	B	C	D

Somatic neural system	Autonomic neural system	Sympathetic	Parasympathetic

Solution:
The PNS is divided into two divisions called somatic neural system and autonomic neural system. The somatic neural system relays impulses from the CNS to skeletal muscles while the autonomic neural system transmits impulses from the CNS to the involuntary organs and smooth muscles of the body. The autonomic neural system is further classified into the sympathetic neural system and parasympathetic neural system.

Topic: Biology, Neural Control and Coordination, NEET
The permissible use of amniocentesis is for

Options:
A detecting genetic abnormality in the foetus
B detecting deficiency diseases in foetus
C detecting gender of the foetus
D both a and b

The correct answer is:
detecting genetic abnormality in the foetus

Solution:
Amniocentesis is a procedure in which a hypodermic needle is inserted in the pregnant abdomen and amniotic fluid is withdrawn. This amniotic fluid contains many fetal cells. The fetal cells can be examined for any chromosomal defects. Thus amniocentesis is a prenatal diagnostic test. It recommended to couples if there is any family history of chromosomal disease.

Topic: Biology, Reproductive Health, NEET
The permissible use of the technique amniocentesis is for

Options:
A detecting sex of the unborn foetus
B artificial insemination
C transfer of embryo into the uterus of a surrogate mother
D detecting any genetic abnormality

The correct answer is:
detecting any genetic abnormality

Solution:
Amniocentesis is a technique for the diagnosis of congenital abnormalities before birth. By karyotypic studies of somatic cells, abnormalities due to changes in chromosome number like Down's syndrome, Turner's syndrome, Klinefelter's syndrome, etc, can be determined.
It can be used as a pre-natal diagnostic technique. These days, amniocentesis is being misused also. Mothers even get their normal foetus aborted if it is a female.

Topic: Biology, Reproductive Health, NEET, NEET 2010 (Screening)
The permissible use of the technique amniocentesis is for

Options:
A Detecting sex of the unborn foetus
B Artificial insemination
C Transfer of embryo into the uterus of a surrogate mother
D Detecting any genetic abnormality.

The correct answer is:
Detecting any genetic abnormality.

Solution:
Amniocentesis is the withdrawal of a sample of the fluid (amniotic fluid) surrounding a foetus in the uterus by piercing the amniotic sac through the abdominal fluid contains cells from the foetus, cell cultures enable chromosome patterns to be studied so that prenatal diagnosis of chromosomal abnormalities can be made. Certain metabolic errors and other abnormalities, such as spina bifida, can also be diagnosed prenatally from analysis of the cells or of the fluid.
As this technique also helps in the detection of the sex of the unborn foetus, it has been banned in order to legally check increasing female foeticides.

Topic: Biology, Reproductive Health, NEET
The person who uses drugs intravenously are much more likely to acquire serious infection like

Options:
A AIDS
B Hepatitis-B
C cancer
D both a and b

The correct answer is:
both a and b

Solution:
AIDS (Acquired Immune Deficiency Syndrome) and Hepatitis-B are considered very serious infections. These are non-curable viral infections. AIDS is caused by HIV, while hepatitis is by the Hepatitis virus. These viral infections spread through sexual contact with multiple sex partners and exchange of needles, as blood is also one of the mode of transmission. These are viral infections that spread through contaminated needles too.

Topic: Biology, Human Health and Diseases, NEET
The petioles that are green and synthesise food is observed in

Options:
A Asparagus
B Euphorbia
C Australian Acacia
D Opuntia

The correct answer is:
Australian Acacia

Solution:
In some plants such as Australian acacia, the leaves
are small and short-lived. The petioles in these plants expand, become green and synthesise food. This leaf modification is known as phyllode, in which lamina is absent and petiole becomes flattened and perform the function of food synthesis.

Topic: Biology, Morphology of Flowering Plants, NEET
The $\mathrm{pH}$ of $0.01 \mathrm{M} \mathrm{NaOH}(a q)$ solution will be

Options:
A 7.01
B 2
C 12
D 9

The correct answer is:
12

Solution:
$\mathrm{NaOH}$ is a strong base, thus
$$
\begin{aligned}
{\left[\mathrm{OH}^{-}\right] } & =0.0 \mathrm{M}=10^{-2} \mathrm{M} \\
\mathrm{pOH} & =-\log \left[\mathrm{OH}^{-}\right]=-\log \left(10^{-2}\right)=2
\end{aligned}
$$
We know that, $\mathrm{pH}+\mathrm{pOH}=14$
$\therefore \quad \mathrm{pH}=14-2=12$
Thus, option (3) is correct.

Topic: Chemistry, Ionic Equilibrium, NEET, NEET 2019 (Odisha)
The pH of 0.1 M solution of the following salts increases in the order

Options:
A KCl<NH4Cl<NaCN<HCl
B HCl<NH4Cl<KCl<NaCN
C NaCN<NH4Cl<KCl<HCl
D HCl<KCl<NaCN<NH4Cl

The correct answer is:
HCl<NH4Cl<KCl<NaCN

Solution:
HCl: Strong acid (low pH)
NH4Cl : Salt of weak base + strong acid → it gives acidic solution. (pH less than 7)
KCl: Salt of strong base + strong base → it gives neutral solution with pH = 7.
NaCN: Salt of strong base + weak acid → it gives basic solution with pH > 7.
Thus the increasing order of pH is
HCl<NH4Cl<KCl<NaCN

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of 0.1M monobasic acid is 4.50. Calculate the concentration of species H⁺.

Options:
A [H⁺] = 3.16 × 10⁻⁴ M
B [H⁺] = 3.16 × 10⁻⁵ M
C [H⁺] = 3.16 × 10⁻³ M
D [H⁺] = 3.16 × 10⁻⁶ M

The correct answer is:
[H⁺] = 3.16 × 10⁻⁵ M

Solution:
Correct Option is : (B)
[H⁺] = 3.16 × 10⁻⁵ M

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of 0.1M solution of cyanic acid (HCNO) is 2.34. Calculate the ionization constant of the acid and its degree of ionization in the solution.

Options:
A Ka = 2.0 × 10-4, α = 0.045
B Ka = 1.5 × 10-3, α = 0.015
C Ka = 1.2 × 10-3, α = 0.016
D Ka = 1.3 × 10-4, α = 0.018

The correct answer is:
Ka = 2.0 × 10-4, α = 0.045

Solution:
Correct Option is : (A)
Ka = 2.0 × 10-4, α = 0.045

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of 0.004M hydrazine solution is 9.7. Calculate its pKb.

Options:
A pKb = 5.3
B pKb = 5.7
C pKb = 6.0
D pKb = 6.3

The correct answer is:
pKb = 6.0

Solution:
Correct Option is : (C)
pKb = 6.0

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of 0.5 M aqueous solution of HF Ka=2×10-4 is

Options:
A 2
B 4
C 6
D 10

The correct answer is:
2

Solution:
Ka=CÎ±2
2Ã104=0.5ÃÎ±2
Î±=2Ã10-2
â´ H+=CÎ±=0.5Ã2Ã10-2=10-2
pH=2

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of 0.005M codeine (C18H21NO3) solution is 9.95. Calculate its ionization constant and pKb.

Options:
A Kb = 0.0158 × 10-4, pKb = 5.80
B Kb = 2.51 × 10-5, pKb = 4.60
C Kb = 5.01 × 10-6, pKb = 4.30
D Kb = 6.01 × 10-6, pKb = 4.80

The correct answer is:
Kb = 0.0158 × 10-4, pKb = 5.80

Solution:
Correct Option is : (A)
Kb = 0.0158 × 10-4, pKb = 5.80

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of a sample of vinegar is 3.76. Calculate the concentration of hydrogen ion in it.

Options:
A 2.6 × 10-4M
B 1.7 × 10-4M
C 4.2 × 10-4M
D 6.4 × 10-4M

The correct answer is:
1.7 × 10-4M

Solution:
Correct Option is : (B)
1.7 × 10-4M

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of a solution obtained by mixing equal volume of solutions having pH = 3 and pH = 4.
[log 5.5 = 0.74]

Options:
A 3.42
B 3.6
C 4.0
D 3.26

The correct answer is:
3.26

Solution:
At pH =3,[H+]=10-3M
At pH =4,[H+]=10-4M
When in equal volume of the two solutions are mixed, the [H+]
=10-3+10-42=10-3[1+0.1]2=1.12×10-3
[H+]=5.5×10-4
-log[H+]=-log(5.5)-log10-4
pH =-0.74+4=3.26

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of a solution prepared by mixing 2.0 ml of HCl solution of pH 3.0 and 3.0 ml of NaOH of pH 10.0 is

Options:
A 3.5
B 2.5
C 6.5
D 5.5

The correct answer is:
3.5

Solution:
Given, for HCl, pH=3
[H+]=10-3=M1
V1=2ml
For NaOH, pH=10,[H+]=10-10=M2
V2=3ml
M1V1-M2V2=MR(V1+V2)
10-3×2-10-10×3=MR(2+3)
2×10-3=5×MR
MR=4×10-4=[H+]
pH=log(4×10-4)=4-0.6020=3.39≈3.5

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of a solution which is three times as acidic as pure water is

Options:
A 6.7
B 3.5
C 7.0
D 6.523

The correct answer is:
6.523

Solution:
In H2O,[H3O+]=1×10-7M
So [H3O+]soln.=3×10-7M
pH=-log[H3O+]
or pH=-log(3×10-7)
=-0.477-(-7)=6.523

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of a solution which is twice as acidic as pure water is (Given: log 2 = 0.3)

Options:
A 7.0
B 3.5
C 6.7
D 14.0

The correct answer is:
6.7

Solution:
In H2O,[H3O+]=1×10-7M
So [H3O+]soln.=2×10-7M
pH=-log[H3O+]
or pH=-log(2×10-7)
=-0.3010-(-7)=6.7

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of aqueous solution of magnesium hydroxide is 9.0. If Ksp of magnesium hydroxide is 1.0× 10 −11   M 3 , then the concentration of magnesium ions in the solution is

Options:
A 10 −7  M
B 10 −2  M
C 0.1 M
D 10 −6  M

The correct answer is:
0.1 M

Solution:
pH=9
So [H+]=10-9molL-1
or [OH-]=10-5molL-1
Ksp[Mg(OH)2]=[Mg2+][OH-]2
So Mg 2+ = 1× 10 −11 ( 10 −5 ) 2 = 10 −1 =0.1 M

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of human urine is approximately

Options:
A 6.5
B 7
C 6
D 7.5

The correct answer is:
6

Solution:
The pH of human urine is approximately 6.

Topic: Biology, Excretory Products and their Elimination, NEET
The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.

Options:
A [H+] = 1.58 × 10-7, 1.00 × 10-5, 6.31 × 10-5, 6.31 × 10-3, 1.58 × 10-8
B [H+] = 1.58 × 10-8, 1.00 × 10-5, 6.31 × 10-6, 6.31 × 10-2, 1.58 × 10-9
C [H+] = 1.58 × 10-6, 1.00 × 10-4, 6.31 × 10-4, 6.31 × 10-2, 1.58 × 10-7
D [H+] = 1.58 × 10-8, 1.00 × 10-4, 6.31 × 10-6, 6.31 × 10-3, 1.58 × 10-9

The correct answer is:
[H+] = 1.58 × 10-7, 1.00 × 10-5, 6.31 × 10-5, 6.31 × 10-3, 1.58 × 10-8

Solution:
Correct Option is : (A)
[H+] = 1.58 × 10-7, 1.00 × 10-5, 6.31 × 10-5, 6.31 × 10-3, 1.58 × 10-8

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of resultant solution of 20 mL of 0.1 M CH 3 COOH and 20 mL of 0.1 M CH 3 COONa is

Options:
A pKa1
B pKa2
C pKa1+pKa22
D 2

The correct answer is:
pKa2

Solution:
CH 3 COOH = CH 3 COONa
The resultant solution will be a buffer solution.
So pH=pKa2+logCH3-COOHCH3-COONa …(ii)
From (i) and (ii)
pH=pKa2 .

Topic: Chemistry, Ionic Equilibrium, NEET
The pH of the digestive juices within the human small intestine is between 7.5 and 8.5. This environment is slightly

Options:
A Basic
B Acidic
C Neutral
D None of these

The correct answer is:
Basic

Solution:
pH refers to the relative concentration of H+ ions in a solution. Low pH values indicate high levels of H+ ions (acids) and high pH values indicate low H+ ions concentrations, which is basic.

Topic: Biology, Digestion and Absorption, NEET
The pH of the solution containing 50 mL each of 0.10 M sodium acetate and 0.01 M acetic acid is
[Given pKa of CH3COOH=4.57]

Options:
A 3.57
B 4.57
C 2.57
D 5.57

The correct answer is:
5.57

Solution:
The given solution is an acidic buffer solution.

According to the Henderson equation for acidic buffer,

pH=pKa+log10saltacid

Given that,

pKa=4.57 salt=sodium acetate=0.1MAcid=Acetic acid=0.01M

Hence, the

pH=4.57+log0.10.01=4.57+1=5.57

Topic: Chemistry, Ionic Equilibrium, NEET, NEET 2022 (Phase 1)
The pH of which salt solution is independent of its concentration
(1) (CH3COO)C5H5NH
(2) NaH2PO4
(3) Na2HPO4
(4) NH4CN

Options:
A 1, 2, 3, 4
B 1, 4
C 2, 3
D 1, 2, 3

The correct answer is:
1, 2, 3, 4

Solution:
pH of amphoteric salts and weak acid weak base salt is independent of its concentration as they act like buffer.

Topic: Chemistry, Ionic Equilibrium, NEET