datavorous/entrance-exam-dataset huggingface dataset:
In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed with a plant that is rrtt,

Options:
A 75% will be tall with red fruit
B 25% will be tall with red fruit
C 50% will be tall with red fruit
D All the offspring will be tall with red fruit

The correct answer is:
50% will be tall with red fruit

Solution:
The genotype of parents is RRTt and rrtt. Hence, colour of the fruits will be red for all the progeny because one of the parents is homozygous dominant. With respect to plant height, the cross can correspond to a monohybrid test cross, and the result for such a cross will be tall: dwarf :: 1:1. The result of the above cross will be tall plant with red fruit: dwarf plant with red fruit :: 1:1

Topic: Biology, Principles of Inheritance and Variation, NEET
In a plant, tallness is dominant over dwarfness and red flowers are incompletely dominant over white flowers, the hybrid being pink. How many offsprings will be of tall height with pink flowers from a cross involved two plants each of which is hybrid tall and has pink flowers?

Options:
A 416
B 616
C 1016
D 216

The correct answer is:
616

Solution:
Hybrid tall: Tt, pink flowers: Rr. Hence, the cross is between TtRr and TtRr. Among the offsprings, only the genotypes TTRr and TtRr are tall and have pink flowers. The proportion of TTRr is 216, whereas the proportion of TtRr is 416 which amounts to a total of 616.

Topic: Biology, Principles of Inheritance and Variation, NEET
In a P-N junction diode, the current in the reverse-biased state is due to

Options:
A Flow of a minority charge carrier from p-side to n-side
B Flow of a majority charge carrier from n-side to p-side
C Flow of a majority charge carrier from p-side to n-side
D Flow of electrons from n-side to p-side

The correct answer is:
Flow of a minority charge carrier from p-side to n-side

Solution:
Current in reverse biased diode is due to movement of minority charge carrier.

Topic: Physics, Semiconductors, NEET
In a polar covalent bond like HF, which atom attracts the shared electron pair more strongly?

Options:
A Hydrogen (H)
B Fluorine (F)
C Both atoms attract it equally.
D The larger atom attracts it more.

The correct answer is:
Fluorine (F)

Solution:
In a polar covalent bond like HF, the shared electron pair is displaced more towards fluorine, indicating that fluorine attracts it more strongly due to its higher electronegativity.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
In a polygenic trait, what is the effect of each allele?

Options:
A The effect of each allele is independent of the others.
B The effect of each allele is multiplicative.
C The effect of each allele is additive.
D The effect of each allele is not relevant to the trait.

The correct answer is:
The effect of each allele is additive.

Solution:
In a polygenic trait, the effect of each allele is additive.

Topic: Biology, Principles of Inheritance and Variation, NEET
In a pond ecosystem, the shape of a pyramid of number is

Options:
A Linear
B Irregular
C Upright
D Inverted

The correct answer is:
Upright

Solution:
The base of each pyramids represents the producers or the first trophic level while the apex represents tertiary or top level consumers. The pyramid of number for pond ecosystem is always upright. Phytoplanktons are chief producers, though their biomass is less but their number is maximum.

Topic: Biology, Ecosystem, NEET
In a pond of water, a flame is held 2 m above the surface of the water. A fish is at depth of 4 m from the water surface. Refractive index of water is 43. The apparent height of the flame from the eyes of fish is -

Options:
A 5.5 m
B 6 m
C 83Â m
D 203Â m

The correct answer is:
203 m

Solution:
Apparent height of flame above water surface.
h′=Â Î¼h=43Ã2=83m
Therefore, apparent height of the flame from the eye of fish
=d+h′=4+83=203m

Topic: Physics, Ray Optics, NEET
In a population, if individuals with extreme properties die and only individuals with average property live, then the selection operating on this population will be:

Options:
A Stabilizing selection
B Directional selection
C Diversifying selection
D Disruptive selection

The correct answer is:
Stabilizing selection

Solution:
Natural selection can lead to stabilization (in which more individuals acquire mean character value), directional change (more individuals acquire value other than the mean character value) or disruption (more individuals acquire peripheral character value at both ends of the distribution curve).

Topic: Biology, Evolution, NEET
In a population of 100 cats, 36 were white and 64 were black. If the black allele is dominant over white allele, what is the frequency of black allele in this population of cats?

Options:
A 0.64
B 0.4
C 0.6
D 0.48

The correct answer is:
0.4

Solution:
According to Hardy Weinberg's equation, p+q=1, where p is the frequency of the dominant allele and q is the frequency of recessive allele in the population. In the given data, 36 cats are white. They have to be pure homozygous individuals have recessive alleles. Thus q2=36/100 and q=0.6. Thus p=1 â 0.6=0.4

Topic: Biology, Evolution, NEET
In a population of 1000 individuals, 500 individuals have Aa genotype and 500 have AA genotype. What will be the proportion of a and A alleles in their gametes?

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

The correct answer is:
1 : 3

Solution:
Individual with genotype Aa will produce two types of gametes in the ratio 1 : 1 (A : a) and the individual with genotype AA will produce only one type of gamete with A. Thus the proportion of alleles a and A in their gametes is 1 : 3.
Therefore,
allele A = (half of Aa + AA) = 250 + 500 = 750
allele a = half of Aa = 250
thus, a:A = 250:750 = 1:3

Topic: Biology, Evolution, NEET
In a population of an area, natality was equal to mortality for a given time period. However, the population density of the population increased. Which of the following may be the reason for the increase?

Options:
A Number of immigrants = number of emigrants
B Number of immigrants > Number of emigrants
C Number of immigrants < Number of emigrants
D Cannot be predicted

The correct answer is:
Number of immigrants > Number of emigrants

Solution:
Natality and immigration contribute to an increase in population density, whereas mortality and emigration tend to decrease the size.

The density of a population (N) at time t can be expressed after a period of time (t + 1) as:

N(t+1) = Nt + [ (B + I) - (D + E) ]

where B denotes the number of births, I denotes the number of immigrants, D is the number of deaths and E is the number of emigrants.

If B = D, and N(t+1) > Nt, then I > E.

Topic: Biology, Organisms and Populations, NEET
In a population of an area, the difference in the natality rate and mortality rate is zero in a particular year, but the population density has decreased. Which of the following may be the reason for that increase?

Options:
A Number of immigrants > Number of emigrants
B Number of immigrants / Number of emigrants = 0
C Number of immigrants < Number of emigrants
D Number of immigrants = Number of emigrants

The correct answer is:
Number of immigrants < Number of emigrants

Solution:
Natality and immigration contribute to an increase in population density, while mortality and emigration tend to decrease the size.

The density of a population (N) at time t can be expressed after a period of time (t + 1) as:

N(t+1) = Nt + [ (B + I) - (D + E) ]

where B denotesthe number of births,I denotesthe number of immigrants,D isthe number of deaths andE is thenumber of emigrants.

If B=D, and N(t+1)< Nt, then I < E.

Topic: Biology, Organisms and Populations, NEET
In a population, unrestricted reproductive capacity is called as:

Options:
A biotic potential
B fertility
C carrying capacity
D birth rate

The correct answer is:
biotic potential

Solution:
Biotic Potential is defined as the physiological capacity of organisms to produce their offspring under natural and environmentally optimum conditions. Biotic potential is the highest possible vital index of a species; therefore, when the species has its highest birth rate and lowest mortality rate.
Related Theory:-
The sum of total inhibitory environmental factors, both biotic and abiotic, which regulate population size and do not permit unlimited growth of population is called environmental resistance. Because of environmental resistance, the populations are unable to reach full biotic potential.

Topic: Biology, Evolution, NEET, NEET 2002
In a potentiometer arrangement, a cell of EMF 2 V gives a balance point at 40 cm length of the wire. If this cell is replaced by another cell and the balance point shifts to 60 cm, then the EMF of the second cell is

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

The correct answer is:
3 V

Solution:
240=V60
V=3 V

Topic: Physics, Current Electricity, NEET
In a potentiometer arrangement shown in fig. The balancing length for potential difference across X, Y points is found to be 45.5 cm. Then the balancing length for potential difference across Y and Z would be

Options:
A 45.50Â cm
B 56.87Â cm
C 36.40 cm
D none of the above

The correct answer is:
36.40 cm

Solution:
V1V2=R1R2=L1L2
=54=45.5L2
L2=45.5Ã45
L2=36.4 cm

Topic: Physics, Current Electricity, NEET
In a potentiometer circuit a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?

Options:
A 64 cm
B 21.6 cm
C 60 cm
D 62 cm

The correct answer is:
60 cm

Solution:
Given,

E1=1.5 V

l1=36 cm

E2=2.5v

l2=?

AS we know,

E1E2=l1l2

1·52·5=36l2

35=36l2

l2=60 cm

Topic: Physics, Current Electricity, NEET, NEET 2021
In a potentiometer experiment if the voltage across resistance R and R+r are balanced at the length l1 and l2 respectively the value of resistance r will be

Options:
A l1-l2l2R
B l1-l2l1R
C l2-l1l1R
D l2-l1l2R

The correct answer is:
l2-l1l1R

Solution:
VR=kl1
VR+r=kl2
R+rR=l2l1
1+rR=l2l1
rR=l2l1-1
rR=l2-l1l1
r=l2-l1l1R

Topic: Physics, Current Electricity, NEET
In a potentiometer experiment, the balancing length of a cell is 560 cm. When an external resistance of 10Ω is connected in parallel to the cell, the balancing length chages by 60 cm. The internal resistance of a cell is

Options:
A 1.4 Î©
B 1.6 Î©
C 0.12 Î©
D 1.2 Î©

The correct answer is:
1.2 Î©

Solution:
Consider a cell of emf E and balancing length l1
E=kl1
The potential difference is balanced by length l2 .
V=kl2
The internal resistance of the cell is given by
r=E-VVR=EV-1R=l1l2-1R
=560560-60-110=5650-110
=65=1.2 Î©

Topic: Physics, Current Electricity, NEET
In a potentiometer experiment, the null point is obtained at a particular point for a cell on potentiometer wire x cm long. If the length of the potentiometer wire is increased without changing the cell, the balancing length will (Driving source is not changed)

Options:
A increase
B decrease
C not change
D becomes zero

The correct answer is:
increase

Solution:
On increasing the length of the potentiometer wire, the potential gradient will decrease, hence longer balancing length is required.

Topic: Physics, Current Electricity, NEET
In a process, 701 J of heat is absorbed by a system and 394 J of work is done by the system. What is the change in internal energy for the process?

Options:
A ∆U = 612 J
B ∆U = 534 J
C ∆U = 412 J
D ∆U = 307 J

The correct answer is:
∆U = 307 J

Solution:
Correct Option is : (D)
∆U = 307 J

Topic: Chemistry, Thermodynamics (C), NEET
In a prokaryotic cell, mesosomes functions is

Options:
A DNA replication and distribution to daughter cells.
B Formation of cell wall, increase the surface area of
the plasma membrane and enzymatic content.
C Respiration and secretion processes.
D All of these

The correct answer is:
All of these

Solution:
A special membranous structure is a mesosome that is formed by the extensions of the plasma membrane into the cell. These extensions are in the form of vesicles, tubules, and lamellae. They help in cell wall formation, DNA replication, and distribution to daughter cells. They also help in respiration, secretion processes, to increase the surface area of the plasma membrane and enzymatic content.

Topic: Biology, Cell - The Unit of Life, NEET
In a protein molecule various amino acids are linked together by:

Options:
A α -glycosidic bond
B β - glycosidic bond
C Peptide bond
D Dative bond

The correct answer is:
Peptide bond

Solution:
In a protein molecule various amino acids are linked together by the peptide bonds.

The peptide bond formed between the two amino acids is shown below. It is formed by the removal of water molecule.

The reaction for the same is given below.

Topic: Chemistry, Biomolecules, NEET, NEET 2016 (Phase 1)
In a protein molecule various amino acids are linked together by:

Options:
A α -glycosidic bond
B β - glycosidic bond
C Peptide bond
D Dative bond

The correct answer is:
Peptide bond

Solution:

Topic: Chemistry, Biomolecules, NEET
In a pseudo first order reaction in water, the following results were obtained:
Calculate the average rate of reaction between the time interval 30 to 60 seconds.

Options:
A 4.67 × 10–3mol L–1s–1
B 6.69 × 10–3mol L–1s–1
C 8.63 × 10–3mol L–1s–1
D 9.05 × 10–3mol L–1s–1

The correct answer is:
4.67 × 10–3mol L–1s–1

Solution:
Correct Option is : (A)
4.67 × 10–3mol L–1s–1

Topic: Chemistry, Chemical Kinetics, NEET
In a pure silicon ni=1016 m-3 crystal at 300 K, 1021 atoms of phosphorus are added per cubic meter. The new hole concentration will be

Options:
A 1021 per m3
B 1019 per m3
C 1011 per m3
D 105 per m3

The correct answer is:
1011 per m3

Solution:
By using mass action law ni2=nenh
⇒nh=ni2ne=101621021=1011 per m3

Topic: Physics, Semiconductors, NEET
In a radioactive decay process, the negatively charged emitted $\beta$-particles are:

Options:
A the electrons produced as a result of the decay of neutrons inside the nucleus
B the electrons produced as a result of collisions between atoms.
C the electrons orbiting around the nucleus
D the electrons present inside the nucleus.

The correct answer is:
the electrons produced as a result of the decay of neutrons inside the nucleus

Solution:
In $\beta^{-}$-decay a neutron is transformed into a proton and an electron is emitted with the nucleus along with an antineutrino.
$n \rightarrow p+\bar{e}+\bar{v}$ where $\bar{v}=$ antinutrino

Topic: Physics, Nuclear Physics, NEET, NEET 2007
In a radioactive disintegration, the ratio of the initial number of atoms to the number of atoms present at an instant of time equal to its mean life is

Options:
A 1e2
B 1e
C e
D e2

The correct answer is:
e

Solution:
Let the initial number of atoms at time t=0 be N0.
Let N be the number of atoms at any instant t.
Mean life Ï=1Î» , where Î» is disintegration constant.
Given , t= Ï
According to radioactive disintegration law,
N=N0e-Î»t
or N=N0e-Î» Ã 1Î» = N0e
or N0N = e

Topic: Physics, Nuclear Physics, NEET
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is Î», then

Options:
A R1=R2e-λ(t1-t2)
B R1=R2eÎ»(t1-t2)
C R1=R2
D R1=R2 (t2t1)

The correct answer is:
R1=R2e-λ(t1-t2)

Solution:
From radioactive decay law.
-dNdt ∝N or-dNdt=λN
Thus, R=-dNdt
Or R= λN or R= λN0e-λt …(i)
Where R0 =λN0 is the activity of the radioactive materialat time t=0.
At time t1, R1=R0e-λt …(ii)
At time t2, R2=R0e-λt …(iii)
Dividing Eq. (ii) by (iii), we have
R1R2=e-λt1e-λt2=e-λ(t1-t2)
or R1=R2e-λ(t1-t2)

Topic: Physics, Nuclear Physics, NEET
In a radioactive material, the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is λ, then

Options:
A R1=R2
B R1=R2e−λt1−t2
C R1=R2eλt1−t2
D R1=R2t2/t1

The correct answer is:
R1=R2e−λt1−t2

Solution:
According to activity law, R = R0e âÎ»t
â´ R1 = R0e âÎ»t1 and R2 = R0e âÎ»t2
â´ Râ¡ 1 Râ¡ 2 = Râ¡ 0 eâ¡ - Î» t 1 Râ¡ 0 eâ¡ - Î» t 2 = eâ¡ - Î» t 1 eâ¡ Î» t 2 = eâ¡ - Î» t 1 - t 2
or R1=R2e−λt1−t2

Topic: Physics, Nuclear Physics, NEET
In a radioactive material the activity at time $t_1$ is $R_1$ and at a later time $t_2$, it is $R_2$. If the decay constant of the material is $\lambda$, then:

Options:
A \(R_1=R_2\)
B \(R_1=R_2 e^{-\lambda\left(t_1-t_2\right)}\)
C \(R_1=R_2 e^{\lambda\left(t_1-t_2\right)}\)
D \(\mathrm{R}_1=\mathrm{R}_2\left(\mathrm{t}_2 / \mathrm{t}_1\right)\)

The correct answer is:
\(R_1=R_2 e^{-\lambda\left(t_1-t_2\right)}\)

Solution:
$R_1=R_0 e^{-\lambda_4}$ and $R_2=R_0 e^{-\lambda \lambda_2}$
$$
\begin{aligned}
\Rightarrow \quad \frac{R_1}{R,} & =\frac{e^{-\lambda \lambda_1}}{e^{-\lambda \lambda_2}} \\
& =e^{-\lambda\left(t_1-t_2\right)} \\
\Rightarrow \quad R_1 & =R_2 e^{-\lambda\left(t_1-t_2\right)}
\end{aligned}
$$

Topic: Physics, Nuclear Physics, NEET, NEET 2006
In a radioactive series, 92238U changes to 82206Pb through n1α decay process and n2β decay process, then

Options:
A n1=8,Â n2=8
B n1=6,Â n2=6
C n1=8, n2=6
D n1=6,Â n2=8

The correct answer is:
n1=8, n2=6

Solution:
92238U→82206Pb+n1α+n2β
From conservation of mass number:
238=206+4n1
32=4n1
⇒n1=8
From conservation of charge:
92=82+2n1-n2
92=82+28-n2
⇒n2=6

Topic: Physics, Nuclear Physics, NEET
In a random mating population in equilibrium, which of the following brings about a change in gene frequency in a non- directional manner?

Options:
A Migration
B Mutations
C Random drift
D Selection

The correct answer is:
Random drift

Solution:
Gene frequencies are conserved from one generation to the other under certain conditions. We also learnt that under these conditions frequencies of genotypes reach an equilibrium after a single generation of random mating. The conditions include absence of mutations, selection, migration and.random drift. These conditions are never fulfilled. Therefore, in a large panmictic (random mating) population, changes in gene frequencies do occur. This change can either be directional as in the case of mutation, selection or migration, or can be nondirectional as in the cases of random drift. The directional change means a change of gene frequencies progressively from one value to another in either direction. If this change is not checked, the forces may lead to eventual fixation of one allele, all other alleles being eliminated. Similarly, the non-directional change means changes which can not be predicted from one generation to the other. The changes in gene frequencies due to different individual factors will be discussed separately.
Migration refers to the movement of individuals into and out of population. Mutation refers to random and sudden heritable variations or changes arising in the genetic constitution.

Topic: Biology, Evolution, NEET
In a random mating population in equilibrium, which one of the following brings about a change in gene frequency in a non-directional manner ?

Options:
A mutations
B random drift
C selection
D migration

The correct answer is:
random drift

Solution:
In a random mating population in equilibrium, random drift brings about a change in gene frequency in a non-directional manner. Random drift is a non- directional factor.

Topic: Biology, Evolution, NEET, NEET 2003
In a reaction, 2A → Products, the concentration of A decreases from 0.5 mol L–1to 0.4 mol L–1in 10 minutes.What is the rate during this interval?

Options:
A Rate of reaction = Rate of disappearance of A = 0.022 mol litre–1min–1
B Rate of reaction = Rate of disappearance of A = 0.012 mol litre–1min–1
C Rate of reaction = Rate of disappearance of A = 0.005 mol litre–1min–1
D Rate of reaction = Rate of disappearance of A = 0.001 mol litre–1min–1

The correct answer is:
Rate of reaction = Rate of disappearance of A = 0.005 mol litre–1min–1

Solution:
Correct Option is : (C)
Rate of reaction = Rate of disappearance of A = 0.005 mol litre–1min–1

Topic: Chemistry, Chemical Kinetics, NEET
In a reaction, 4 mole of electrons are transformed to 1 mole of HNO3, the possible product formed for the reduction is :

Options:
A 0.5 mole of N2
B 0.5 mole of N2O
C 1 mole of NO3
D 1 mole of NH3

The correct answer is:
0.5 mole of N2O

Solution:
This equation is involved in the reaction 2N5++8e-âN+2
Two moles of HNO3 gives one mole of N2O.
Therefore 0.5 mole of N2O is correct.

Topic: Chemistry, Redox Reactions, NEET
In a reaction A + B2→ AB2Identify the limiting reagent, if any, in the following reaction mixture- 2 mol A + 3 mol B

Options:
A A is the limiting reagent
B B is the limiting reagent
C No limiting reagent for the reaction
D Cannot be calculated without more information

The correct answer is:
A is the limiting reagent

Solution:
Correct Option is : (A)
A is the limiting reagent

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
In a reaction A + B2→ AB2Identify the limiting reagent, if any, in the following reaction mixture- 5 mol A + 2.5 mol B

Options:
A A is the limiting reagent
B B is the limiting reagent
C No limiting reagent for the reaction
D Cannot be calculated without more information

The correct answer is:
B is the limiting reagent

Solution:
Correct Option is : (B)
B is the limiting reagent

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
In a reaction A + B2→ AB2Identify the limiting reagent, if any, in the following reaction mixture- 2.5 mol A + 5 mol B

Options:
A A is the limiting reagent
B B is the limiting reagent
C No limiting reagent for the reaction
D Cannot be calculated without more information

The correct answer is:
B is the limiting reagent

Solution:
Correct Option is : (B)
B is the limiting reagent

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
In a reaction A + B2→ AB2Identify the limiting reagent, if any, in the following reaction mixture- 100 atoms of A + 100 molecules of B

Options:
A A is the limiting reagent
B B is the limiting reagent
C No limiting reagent for the reaction
D Cannot be calculated without more information

The correct answer is:
No limiting reagent for the reaction

Solution:
Correct Option is : (C)
No limiting reagent for the reaction

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
In a reaction A + B2→ AB2Identify the limiting reagent, if any, in the following reaction mixture- 300 atoms of A + 200 molecules of B

Options:
A A is the limiting reagent
B B is the limiting reagent
C No limiting reagent for the reaction
D Cannot be calculated without more information

The correct answer is:
B is the limiting reagent

Solution:
Correct Option is : (B)
B is the limiting reagent

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
In a reaction, $A+B \rightarrow$ Product, rate is doubled when the concentration of $B$ is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants $(A$ and $B$ ) are doubled. Rate law for the reaction can be written as

Options:
A Rate $=k[A][B]^2$
B Rate $=k[A]^2[B]^2$
C Rate $=k[A][B]$
D Rate $=k[A]^2[B]$

The correct answer is:
Rate $=k[A]^2[B]$

Solution:
Let the order of reaction with respect to $A$ and $B$ is $x$ and $y$ respectively. So, the rate law can be given as
$R=k[A]^x[B]^y$
When the concentration of only $B$ is doubled, the rate is doubled, so
$R_1=k[A]^x[2 B]^y=2 R$
If concentrations of both the reactants $A$ and $B$ are doubled, the rate increases by a factor of 8 , so
$\begin{aligned}
R^{\prime \prime}=k[2 A]^x[2 B]^y & =8 R \\
\Rightarrow k 2^x 2^y[A]^x[B]^y & =8 R
\end{aligned}$
From Eq. (i) and (ii), we get
$\begin{array}{rlrl}
& \Rightarrow & \frac{2 R}{R} & =\frac{[A]^x[2 B]^y}{[A]^x[B]^y} \\
& \therefore & =2^y \\
& y & =1
\end{array}$
From Eq. (i) and (iv), we get
$\Rightarrow \frac{8 R}{R}=\frac{2^x 2^y[A]^x[B]^y}{[A]^x[B]^y}$
or $8=2^x 2^y$
Substitution of the value of $y$ gives,
$\begin{aligned}
& 8=2^x 2^1 \\
& 4=2^x
\end{aligned}$
$\begin{aligned}
& & (2)^2 & =(2)^x \\
\therefore & & x & =2
\end{aligned}$
Substitution of the value of $x$ and $y$ in Eq. (i) gives,
$R=k[A]^2[B]$

Topic: Chemistry, Chemical Kinetics, NEET, NEET 2012 (Screening)