List of top Questions asked in NEET (UG)

De-Broglie wavelength of an electron orbiting in the $n = 2$ state of hydrogen atom is close to (Given Bohr radius = 0.052 nm):

A photon and an electron (mass $m$) have the same energy $E$. The ratio $ \frac{\lambda_{\text{photon}}}{\lambda_{\text{electron}}} $ of their de Broglie wavelengths is: ($c$ is the speed of light)

Consider the diameter of a spherical object being measured with the help of a Vernier Callipers. Suppose its 10 Vernier Scale Divisions (V.S.D.) are equal to its 9 Main Scale Divisions (M.S.D.). The least count in the M.S. is 0.1 cm and the zero of V.S. is at -0.1 cm when the jaws of Vernier callipers are closed. If the main scale reading for the diameter is $M = 5$ cm and the number of coinciding vernier division is 8, the measured diameter after zero error correction, is:

A 2 amp current is flowing through two different small circular copper coils having radii ratio 1:2. The ratio of their respective magnetic moments will be:

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at $22.5^\circ$ from the polarization axis of one of the polaroids ($I_0$ is the intensity of polarised light after passing through the first polaroid):

Which of the following are paramagnetic?
A. [NiCl$_4$]$^{2-}$
B. Ni(CO)$_4$
C. [Ni(CN)$_4$]$^{2-}$
D. [Ni(H$_2$O)$_6$]$^{2+}$
E. Ni(PPh$_3$)$_4$
Choose the correct answer from the options given below:

Consider the following compounds: K$_2$O$_2$, H$_2$O$_2$, and H$_2$SO$_4$
The oxidation states of the underlined elements in them are, respectively:

C(s) + 2H$_2$(g) $\rightarrow$ CH$_4$(g); $\Delta H = -74.8 \, \text{kJ mol}^{-1}$
Which of the following diagrams gives an accurate representation of the above reaction?

5 moles of liquid X and 10 moles of liquid Y make a solution having a vapor pressure of 70 torr. The vapor pressures of pure X and Y are 63 torr and 78 torr, respectively. Which of the following is true regarding the described solution?

Which among the following electronic configurations belong to main group elements?
A. [Ne]3s$^1$
B. [Ar]3d$^3$4s$^2$
C. [Kr]4d$^5$3s$^2$5p$^5$
D. [Ar]3d$^10$4s$^1$
E. [Rn]5f$^7$6d$^2$7s$^2$
Choose the correct answer from the options given below:

If the rate constant of a reaction is 0.03 s$^{-1}$, how much time does it take for a 7.2 mol L$^{-1}$ concentration of the reactant to get reduced to 0.9 mol L$^{-1}$?
(Given: log 2 = 0.301)

Match List I with List II:

Choose the correct answer from the options given below:

The correct order of the wavelength of light absorbed by the following complexes is:
A. $[ \text{Co(NH}_3\text{)}_6]^{3+}$
B. $[ \text{Co(CN)}_6]^{3-}$
C. $[ \text{Cu(H}_2\text{O)}_4]^{2+}$
D. $[ \text{Ti(H}_2\text{O)}_6]^{3+}$
Choose the correct answer from the options given below:

The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes n = 2 $\rightarrow$ n = 3 and n = 4 $\rightarrow$ n = 6 transitions, respectively, is:

Match List I with List II:

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Higher yield of NO in the reaction
N$_2$ (g) + O$_2$ (g) $\rightarrow$ 2NO (g)
can be obtained at [$\Delta H$ of the reaction = +180.7 kJ mol$^{-1}$]

Which of the following aqueous solutions will exhibit the highest boiling point?

If the half-life ($t_{1/2}$) for a first-order reaction is 1 minute, then the time required for 99.9% completion of the reaction is closest to:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): I$^-$ undergoes SN$_2$ reaction faster than Cl$^-$.
Reason (R): Iodine is a better leaving group because of its large size.
In the light of the above statements, choose the correct answer from the options given below:

Energy and radius of first Bohr orbit of He$^+$ and Li$^2+$ are:
Given: $ R_H = 2.18 \times 10^{-18} \, \text{J}, a_0 = 52.9 \, \text{pm} $

Match List I with List II:
$Wacker oxidation & & II. PdCl\textsubscript{2} C. Wilkinson catalys$
Choose the correct answer from the options given below:

The standard heat of formation, in kcal/mol, of $Ba^{2+}$ is:
Given: Standard heat of formation of SO₄²⁻(aq) = -216 kcal/mol, standard heat of crystallization of BaSO₄(s) = -4.5 kcal/mol, standard heat of formation of BaSO₄(s) = -349 kcal/mol.

Match List I with List II:

Choose the correct answer from the options given below:

Dalton’s Atomic Theory could not explain which of the following?

Phosphoric acid ionizes in three steps with their ionization constant values $ K_1 $, $ K_2 $, and $ K_3 $, respectively, while $ K $ is the overall ionization constant.
Which of the following statements are true?