List of top Chemistry Questions

In the lewis dot structure for \(NO^{-}_{2}\), total number of valence electrons around nitrogen is .......

The number of halobenzenes from the following that can be prepared by Sandmeyer's reaction is .......

9.3 g of pure aniline is treated with bromine water at room temperature to give a white precipitate of the product 'P'. The mass of product 'P' obtained is 26.4 g. The percentage yield is ......... %.

The heat of combustion of solid benzoic acid at constant volume is \(-321.30 \, \text{kJ}\) at \(27^\circ \text{C}\). The heat of combustion at constant pressure is \((-321.30 - xR)\, \text{kJ}\). The value of \(x\) is:

An artificial cell is made by encapsulating \(0.2 \, \text{M}\) glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a \(0.05 \, \text{M}\) solution of NaCl at 300 K is ______ \( \times 10^{-1} \, \text{bar} \). (Nearest Integer)
Given: \(R = 0.083 \, \text{L bar mol}^{-1} \text{K}^{-1}\)
Assume complete dissociation of NaCl.

During Kinetic study of reaction 2A + B \(\mapsto \) C + D, the following results were obtained:

	A[M]	B[M]	initial rate of formation of D
I	0.1	0.1	6.0 × 10-3
II	0.3	0.2	7.2 × 10-2
III	0.3	0.4	2.88 × 10-1
IV	0.4	0.1	2.40 × 10-2

Based on above data, overall order of the reaction is ..........

Consider the given chemical reaction sequence :

Total sum of oxygen atoms in Product A and Product B are .........

The spin-only magnetic moment value of the ion among \( \text{Ti}^{2+}, \text{V}^{2+}, \text{Co}^{3+}, \text{and} \, \text{Cr}^{2+} \), that acts as a strong oxidizing agent in aqueous solution is:\(\dots\) BM (Nearest integer).
Given atomic numbers: Ti: 22, V: 23, Cr: 24, Co: 27

In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame, resulted in green colour salt bead. The spin-only magnetic moment value of the salt is ............. BM (Nearest integer)
[Given atomic number of Cu = 29, Ni = 28,Mn = 25, Fe = 26]

\(C_{11}H_{18}O_{12}\)The value of the Rydberg constant (\(R_H\)) is \(2.18 \times 10^{-18} \, \text{J}\). The velocity of an electron having mass \(9.1 \times 10^{-31} \, \text{kg}\) in Bohr's first orbit of the hydrogen atom is:\(\dots \times 10^5 \, \text{ms}^{-1}\) (nearest integer).

Which of the following gives a positive test with ninhydrin ?

Given below are two statements:
Statement I: Bromination of phenol in a solvent with low polarity such as CHCl\(_3\) or CS\(_2\) requires a Lewis acid catalyst.
Statement II: The Lewis acid catalyst polarizes the bromine to generate \( \text{Br}^+ \).
In light of the above statements, choose the correct answer from the options given below:

Ail organic compound has 42.1% carbon, 6.4% hydrogen and remainder is oxygen. If its molecular weight is 342, then its molecular formula is :

The metal that shows highest and maximum number of oxidation state is:

The number of neutrons present in the more abundant isotope of boron is 'x'. Amorphous boron upon heating with air forms a product, in which the oxidation state of boron is 'y'. The value of x + y is ...

molar ionic conductivities of a divalent cation and anion are \(57 \, \text{S cm}^2 \text{mol}^{-1}\) and \(73 \, \text{S cm}^2 \text{mol}^{-1}\), respectively. The molar conductivity of the solution of an electrolyte with the above cation and anion will be:

Identify 'A' in the following reaction :

Which one of the following complexes will exhibit the least paramagnetic behaviour ? [Atomic number, Cr = 24, Mn = 25, Fe = 26, Co = 27]

The reaction at cathode in the cells commonly used in clocks involves.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Cis form of alkene is found to be more polar than the trans form
Reason (R): Dipole moment of trans isomer of 2-butene is zero. In the light of the above statements.
Choose the correct answer from the options given below :

The correct order of ligands arranged in increasing field strength.

Given below are two statements :
Statement I: Nitration of benzene involves the following step –

Statement II: Use of Lewis base promotes the electrophilic substitution of benzene. In the light of the above statements.
Choose the most appropriate answer from the options given below :

Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always –57 kJ mol^–1
Reason (R): Enthalpy of neutralisation is the amount of heat liberated when one mole of H⁺ ions furnished by acid combine with one mole of ^–OH ions furnished by base to form one mole of water. In the light of the above statements.
Choose the correct answer from the options given below.

Identify compound (Z) in the following reaction sequence.

Number of σ and π bonds present in ethylene molecule is respectively :