List of top Chemistry Questions

Arrange the following resultant mixtures in increasing order of their pH values}
A. \(10 \text{ mL } 0.2 \text{ M Ca(OH)}_2 + 25 \text{ mL } 0.1 \text{ M HCl}\)
B. \(10 \text{ mL } 0.01 \text{ M H}_2\text{SO}_4 + 10 \text{ mL } 0.01 \text{ M Ca(OH)}_2\)
C. \(10 \text{ mL } 0.1 \text{ M H}_2\text{SO}_4 + 10 \text{ mL } 0.1 \text{ M KOH}\)

\(M_3A_2\) is a sparingly soluble salt of molar mass \(y \text{ g mol}^{-1}\) and solubility \(x \text{ g L}^{-1}\). The ratio of the molar concentration of the anion (\(A^{3-}\)) to the solubility product (\(K_{sp}\)) of the salt is:

Identify the correct statements from the following :}
A. Heisenberg uncertainty principle is applicable to electrons.
B. The size of \(2p_x\) orbital is less than the size of \(3p_x\) orbital.
C. The energy of \(2s\) orbital of H atom is equal to the energy of \(2s\) orbital of Li.
D. The electronic configuration of Cr is \([Ar] 3d^5 4s^1\)

Arrange the following atomic orbitals of multi electron atoms in order of increasing energy.
A. \(n=3, l=2, m=+1\)
B. \(n=4, l=0, m=0\)
C. \(n=6, l=1, m=0\)
D. \(n=5, l=1, m=+1\)
E. \(n=2, l=1, m=+1\)

How many grams of residue is obtained by heating \(2.76 \text{ g}\) of silver carbonate? (Given : Molar mass of C, O and Ag are 12, 16 and \(108 \text{ g mol}^{-1}\) respectively)

The correct statements among the following are:
A. Mo(VI) and W(VI) are less stable than Cr(VI).
B. Ce⁴⁺ and Tb⁴⁺ are oxidant while Eu²⁺ and Yb²⁺ are reductant.
C. Cm and Am have seven unpaired electrons.
D. Actinoid contraction is greater from element to element than lanthanoid contraction.
Choose the correct answer:

Statement I: The covalency of oxygen is generally two but it can exceed up to four. The oxidation state of oxygen in SO₂ is -2 and in OF₂ it is +2.
Statement II: The anomalous behaviour of oxygen when compared to the other elements of group 16 is due to its small size and high electronegativity.
In the light of the above statements, choose the correct answer:

A monoatomic anion (A⁻) has 45 neutrons and 36 electrons. Atomic mass, group in the periodic table and physical state at room temperature of the element (A) respectively are

Consider the first order reaction R → P. The fraction of molecules decomposed in the given first order reaction can be expressed as

In order to oxidise a mixture of 1 mole each of FeC₂O₄, Fe₂(C₂O₄)₃, FeSO₄ and Fe₂(SO₄)₃ in acidic medium, the number of moles of KMnO₄ required is

At T(K), the equilibrium constant of \(A_2(g) + B_2(g) \rightleftharpoons C(g)\) is \(2.7 \times 10^{-5}\). What is the equilibrium constant for \(\frac{1}{3} A_2(g) + \frac{1}{3} B_2(g) \rightleftharpoons \frac{1}{3} C(g)\) at the same temperature?

Statement I: For an ideal gas, heat capacity at constant volume is always greater than the heat capacity at constant pressure.
Statement II: In a constant volume process, no work is produced and all the heat withdrawn goes into the chaotic motion and is reflected by a temperature increase of the ideal gas.
In the light of the above statements, choose the correct answer:

Which of the following is correct set of 4 quantum numbers of 19th electron in Chromium (Atomic number = 24) in accordance with Aufbau principle?

What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

The number of molecules present in $2.8\,g$ of nitrogen is

The common name of 2-Butanone is

Which among the following pairs are not having same number of total electrons?

The half life period of a radioactive element is $150$ days. After $600$ days $1\,g$ of the element will be reduced to

Consider the following reaction sequence in which \(J, K, L\) and \(M\) are the major products.

Given:
Atomic mass (in amu): H : \(1\), C : \(12\), N : \(14\), O : \(16\), S : \(32\), Br : \(80\), Ba : \(137\)

In sulphur estimation by Carius method, the amount of \(\text{BaSO}_4\) formed from \(3.79\,\text{g}\) of \(M\) is _____ g.

Consider the following reaction sequence in which \(J, K, L\) and \(M\) are the major products.

Given:
Atomic mass (in amu): H : \(1\), C : \(12\), N : \(14\), O : \(16\), S : \(32\), Br : \(80\), Ba : \(137\)

The volume of \(1\,\text{M}\) aqueous \(\text{H}_2\text{SO}_4\) required to completely neutralize the ammonia evolved from \(5.72\,\text{g}\) of \(L\) in Kjeldahl’s method of nitrogen estimation is _____ mL.

Two volatile liquids A and B form an ideal solution. Consider a 5 molal solution of B in A inside a closed container having a total vapour pressure of 100 mm Hg at 300 K. The vapour pressure of pure A at 300 K is 105 mm Hg. Assume that A and B behave as ideal gases in the vapour phase.
Given: The gas constant \(R = 0.08 \,\text{L atm K}^{-1}\text{ mol}^{-1}\)
Molar mass of A is \(50 \,\text{g mol}^{-1}\)
Molar mass of B is \(57 \,\text{g mol}^{-1}\)
Density of liquid B at \(300\,\text{K}\) is \(0.5 \,\text{g mL}^{-1}\)
\(1\,\text{atm} = 760\,\text{mm Hg}\)
The mole fraction of B in vapour phase which is in equilibrium with this solution is _______.

Two volatile liquids A and B form an ideal solution. Consider a 5 molal solution of B in A inside a closed container having a total vapour pressure of 100 mm Hg at 300 K. The vapour pressure of pure A at 300 K is 105 mm Hg. Assume that A and B behave as ideal gases in the vapour phase.
Given: The gas constant \(R = 0.08 \,\text{L atm K}^{-1}\text{ mol}^{-1}\)
Molar mass of A is \(50 \,\text{g mol}^{-1}\)
Molar mass of B is \(57 \,\text{g mol}^{-1}\)
Density of liquid B at \(300\,\text{K}\) is \(0.5 \,\text{g mL}^{-1}\)
\(1\,\text{atm} = 760\,\text{mm Hg}\)

At 300 K, the ratio of the molar volume of pure B in vapour phase to its molar volume in liquid phase is _______.

In the following reaction sequence, major products X and Y are acyclic monomers.
\(\text{CH}_3\text{I} \xrightarrow{\text{1. KCN}}{\text{2. H}_3\text{O}^+, \Delta}{\text{3. Red P, Br}_2}{\text{4. NH}_3\text{ (excess) \text{X} \)
\(\text{Caprolactam} \xrightarrow{\text{H}_3\text{O}^+, \Delta} \text{Y} \)
500 mol of X completely reacts with 500 mol of Y to give 1 mol of a single biodegradable acyclic copolymer Z as the only product. The amount of Z formed in grams is _______.
Given: Atomic mass (in amu): H : 1, C : 12, N : 14, O : 16, Br : 80}

Consider that the coordinating atoms of the ligands in cis-[Co(NH$_3$)$_4$Cl$_2$]Cl and mer-[Co(NH$_3$)$_3$Cl$_3$] octahedral complexes are at the vertices of an octahedron. The sum of total number of the triangular faces in both the complexes having one N atom and two Cl atoms at their corners is _______.

In a solvent S, a compound B is partially dissociated into C and D as given below:
B \(\rightleftharpoons\) 2C + 2D
B, C and D are non-volatile in nature. The molar mass of B is 10 times the molar mass of S. The standard boiling point and the standard enthalpy of vaporization of S are 400 K and 10R J mol\(^{-1}\), respectively (R is the gas constant in J K\(^{-1}\) mol\(^{-1}\)). A solution of B in S with an initial concentration of B as 0.25% (mass/mass) has a boiling point of 408 K at 1 bar pressure. In this solution, the mole percent of B that has been dissociated is _______.