List of top Chemistry Questions

Given below are two statements:
Statement (I): The 4f and 5f-series of elements are placed separately in the Periodic table to preserve the principle of classification.
Statement (II): s-block elements can be found in pure form in nature.
In the light of the above statements, choose the most appropriate answer from the options given below:

Among the following, total number of meta directing functional groups is (Integer based) \(−OCH_3​, −NO_2​, −CN, −CH_3​, −NHCOCH_3​, −COR, −OH, −COOH, −Cl\).

$\text{Two reactions are given below:}$ \[ 2\text{Fe}_{(s)} + \frac{3}{2}\text{O}_{2(g)} \rightarrow \text{Fe}_2\text{O}_{3(s)}, \Delta H^\circ = -822 \, \text{kJ/mol} \] \[ \text{C}_{(s)} + \frac{1}{2}\text{O}_{2(g)} \rightarrow \text{CO}_{(g)}, \Delta H^\circ = -110 \, \text{kJ/mol} \] $\text{Then enthalpy change for the following reaction}$ \[ 3\text{C}_{(s)} + \text{Fe}_2\text{O}_{3(s)} \rightarrow 2\text{Fe}_{(s)} + 3\text{CO}_{(g)} \]

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Melting point of Boron (2453 K) is unusually high in group 13 elements.
Reason (R): Solid Boron has a very strong crystalline lattice. 
In the light of the above statements, choose the most appropriate answer from the options given below:

Which of the following has highly acidic hydrogen?

The mass of silver (Molar mass of Ag : 108 gmol^–1 ) displaced by a quantity of electricity which displaces 5600 mL of O₂ at S.T.P. will be _____ g.

Sum of bond order of CO and NO⁺ is _____.

Given below are two statements:
Statement (I): Aqueous solution of ammonium carbonate is basic.
Statement (II): Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on \( K_a \) and \( K_b \) value of acid and the base forming it.
In the light of the above statements, choose the most appropriate answer from the options given below:

A solution of two miscible liquids showing negative deviation from Raoult's law will have:

NaCl reacts with conc. \( H_2SO_4 \) and \( K_2Cr_2O_7 \) to give reddish fumes (B), which react with NaOH to give yellow solution (C). (B) and (C) respectively are:

3-Methylhex-2-ene on reaction with HBr in presence of peroxide forms an addition product (A). The number of possible stereoisomers for 'A' is ______.

Among the given organic compounds, the total number of aromatic compounds is

If three moles of an ideal gas at 300 K expand isothermally from 30 dm³ to 45 dm³ against a constant opposing pressure of 80 kPa, then the amount of heat transferred is ______ J.

The correct statement regarding nucleophilic substitution reaction in a chiral alkyl halide is:

Yellow compound of lead chromate gets dissolved on treatment with hot NaOH solution. The product of lead formed is a:

Consider the following complex ions:
P = \([FeF_6]^{3-}\) 
Q = \([V(H_2O)_6]^{2+}\) 
R = \([Fe(H_2O)_6]^{2+}\) 
The correct order of the complex ions, according to their spin-only magnetic moment values (in B.M.) is:

Number of spectral lines obtained in He⁺ spectra, when an electron makes transition from fifth excited state to first excited state will be __________.

The total number of correct statements, regarding the nucleic acids is_________.
A. RNA is regarded as the reserve of genetic information.
B. DNA molecule self-duplicates during cell division.
C. DNA synthesizes proteins in the cell.
D. The message for the synthesis of particular proteins is present in DNA.
E. Identical DNA strands are transferred to daughter cells.

Mass of methane required to produce 22 g of CO₂​ after complete combustion is ______ g.
(Given Molar mass in g mol⁻¹: C=12.0, H=1.0, O=16.0).

The half-life of radio isotopic bromine - 82 is 36 hours. The fraction which remains after one day is ___________ ×10^–2.
(Given antilog 0.2006 = 1.587)

Which of the following statements are correct about Zn, Cd and Hg?
A. They exhibit high enthalpy of atomization as the d-subshell is full.
B. Zn and Cd do not show variable oxidation state while Hg shows +I and +II.
C. Compounds of Zn, Cd and Hg are paramagnetic in nature.
D. Zn, Cd and Hg are called soft metals.
Choose the most appropriate from the options given below:

Alkaline oxidative fusion of \(MnO_2\) gives “A” which on electrolytic oxidation in alkaline solution produces B. A and B respectively are:

Anomalous behaviour of oxygen is due to its

Which one of the following will show geometrical isomerism?