List of top Chemistry Questions asked in NEET (UG)

Among the given compounds I-III, the correct order of bond dissociation energy of the C-H bond marked with is:
Which one of the following reactions does NOT belong to “Lassaigne's test”?
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:

Predict the major product $ P $ in the following sequence of reactions:
(i) HBr, benzoyl peroxide 
(ii) KCN 
(iii) Na(Hg), $C_{2}H_{5}OH$

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.

If the molar conductivity ($\Lambda_m$) of a 0.050 mol $L^{–1}$ solution of a monobasic weak acid is 90 S $cm^{2} mol^{–1}$, its extent (degree) of dissociation will be:
[Assume: $\Lambda^0$ = 349.6 S $cm^{2} mol^{–1}$ and $\Lambda^0_{\text{acid}}$ = 50.4 S$ cm^{2} mol^{–1}$]

The major product of the following reaction is:
$Ph-C(=O)-CH_2CH_2-CN$
(i) $CH_{3}MgBr (excess) (ii) H_{+}H_{2}O$

Identify the suitable reagent for the following conversion: $Ph-C(=O)-OCH_3$ $\longrightarrow$ $Ph-CHO$

For the reaction A(g) $\rightleftharpoons$ 2B(g), the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500, at 1000 K.
[Given: R = 0.0831 atm $mol^{–1} K^{–1}$]
$K_p$ for the reaction at 1000 K is:

Given below are two statements:
Statement I: Ferromagnetism is considered as an extreme form of paramagnetism.
Statement II: The number of unpaired electrons in a $Cr^{2+}$ ion (Z = 24) is the same as that of a $Nd^{3+}$ ion (Z = 60).
In the light of the above statements, 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:
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)
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:
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?
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?
Which one of the following compounds does not decolorize bromine water?
Given below are two statements:
Statement I: A hypothetical diatomic molecule with bond order zero is quite stable.
Statement II: As bond order increases, the bond length increases.
In the light of the above statements, choose the most appropriate answer from the options given below:
Dalton’s Atomic Theory could not explain which of the following?
Out of the following complex compounds, which of the compound will be having the minimum conductance in solution?

Among the following, choose the ones with an equal number of atoms.

  1. 212 g of Na2CO3 (s) [molar mass = 106 g]
  2. 248 g of NaNO3 (s) [molar mass = 62 g]
  3. 240 g of NaOH (s) [molar mass = 40 g]
  4. 12 g of H2 (g) [molar mass = 2 g]
  5. 220 g of CO2 (g) [molar mass = 44 g]

Choose the correct answer from the options given below:

Which one of the following compounds can exist as cis-trans isomers?

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:

Given below are two statements:
Statement I: Benzendiazonium salt is prepared by the reaction of aniline with nitrous acid at 273-278 K. It decomposes easily in the dry state.
Statement II: Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzendiazonium salt with KI.
In the light of the above statements, choose the most appropriate answer from the options given below:
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: