List of top Chemistry Questions

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): SN$_2$ reaction of C$_6$H$_5$CH$_2$Br occurs more readily than the SN$_2$ reaction of CH$_3$CH$_2$Br.
Reason (R): The partially bonded unhybridized p-orbital that develops in the trigonal bipyramidal transition state is stabilized by conjugation with the phenyl ring.
In the light of the above statements, choose the most appropriate answer from the options given below:

Number of compounds from the following which cannot undergo Friedel-Crafts reactions is :____
toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, m-nitroaniline, m-dinitrobenzene

In the given TLC, the distance of spot \( A \) and \( B \) are 5 cm and 7 cm, from the bottom of the TLC plate, respectively. The \( R_f \) value of \( B \) is \( x \times 10^{-1} \) times more than \( A \). The value of \( x \) is _________ .

Number of moles of \(H^+\) required by \(1\) mole \(MnO_4^-\) to oxidize oxalate ion to \(CO_2\) is ____ .

In the given molecule,

the number of chiral centers is _______.

The data provided in the table were obtained from the following reaction, carried out at 273 𝐾.
𝐴 + 𝐵 → 𝐶 

Initial concentration of [𝐴] 𝑚𝑜𝑙 $𝐿 ^{−1}$	Initial concentration of [𝐵] 𝑚𝑜𝑙$𝐿 ^{−1}$	Initial rate of formation of [𝐶] 𝑚𝑜𝑙 $𝐿^{−1} 𝑠 ^{−1}$
0.2	0.2	0.3
0.4	0.2	0.6
0.4	0.4	2.4

The order of the reaction with respect to 𝐴 is _________.

Which of the following technique(s) can be used to determine the three - dimensional structure of an organic compound?

The boiling points of Iodomethane, Dibromomethane, Bromomethane, Chloromethane follow the order

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will -

Identify correct statements from below:
A. The chromate ion is square planar. 
B. Dichromates are generally prepared from chromates. 
C. The green manganate ion is diamagnetic. 
D. Dark green coloured \(K_2​MnO_4\)​ disproportionates in a neutral or acidic medium to give permanganate. 
E. With increasing oxidation number of transition metal, ionic character of the oxides decreases. 
Choose the correct answer from the options given below:

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning

A pair of isoelectronic species having a bond order of one is:

A metalloid is:

From the diagram

\( \Delta H \) for the reaction C → A is:

Identify the wrong relation for real gases:

For which one of the following mixtures is composition uniform throughout?

The transition element (≈5%) present with lanthanoid metal in Misch metal is:

Identify the incorrect statement from the following:

Which of the following statements related to lanthanoids is incorrect?

The correct decreasing order of boiling points of hydrogen halides is:

Select the correct statement:

For the coagulation of positively charged hydrated ferric-oxide sol, the flocculating power of the ions is in the order:

$NO_2$ gas is :