List of top Chemistry Questions

Match List-I with List-II:

Total number of molecules/species from the following which will be paramagnetic is ________________________. \[ O_2, O_2^+, O_2^-, NO, NO_2, CO, K_2[NiCl_4], [Co(NH_3)_6]Cl_3, K_2[Ni(CN)_4] \]

Consider the following data: - Heat of formation of \( CO_2(g) \) = -393.5 kJ mol\(^{-1}\) - Heat of formation of \( H_2O(l) \) = -286.0 kJ mol\(^{-1}\) - Heat of combustion of benzene = -3267.0 kJ mol\(^{-1}\) The heat of formation of benzene is ________________________ kJ mol\(^{-1}\) (Nearest integer).

The spin-only magnetic moment (\(\mu\)) value (B.M.) of the compound with the strongest oxidising power among \(Mn_2O_3\), \(TiO\), and \(VO\) is ________________________ B.M. (Nearest integer).

The total number of compounds from below when treated with hot KMnO4 giving benzoic acid is:

The major product of the following reaction is:

An ideal gas undergoes a cyclic transformation starting from point A and coming back to the same point by tracing the path A→B→C→D→A as shown in the three cases below.

Choose the correct option regarding \(\Delta U\):

Match List - I with List - II.

Choose the correct answer from the options given below:

Identify the inorganic sulphides that are yellow in colour: (A) \( ({NH}_4)_2{S} \)
(B) \( {PbS} \)
(C) \( {CuS} \)
(D) \( {As}_2{S}_3 \)
(E) \( {As}_2{S}_5 \)
Choose the correct answer from the options given below:

Given below are two statements: Statement (I): According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement (II): Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers. In the light of the above statements, choose the correct answer from the options given below:

For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth? Where \( N \) - Number of Bacteria at any time, \( N_0 \) - Initial number of Bacteria.

Identify product [A], [B], and [C] in the following reaction sequence.

Consider the following reaction occurring in the blast furnace. \[ {Fe}_3{O}_4(s) + 4{CO}(g) \rightarrow 3{Fe}(l) + 4{CO}_2(g) \] ‘x’ kg of iron is produced when \(2.32 \times 10^3\) kg \(Fe_3O_4\) and \(2.8 \times 10^2 \) kg CO are brought together in the furnace.
The value of ‘x’ is __________ (nearest integer).

X g of benzoic acid on reaction with aqueous \(NaHCO_3\) release \(CO_2\) that occupied 11.2 L volume at STP. X is ________ g.

Standard entropies of \(X_2\), \(Y_2\) and \(XY_5\) are 70, 50, and 110 J \(K^{-1}\) mol\(^{-1}\) respectively. The temperature in Kelvin at which the reaction \[ \frac{1}{2} X_2 + \frac{5}{2} Y_2 \rightarrow XY_5 \quad \Delta H = -35 \, {kJ mol}^{-1} \] will be at equilibrium is (nearest integer):

37.8 g \( N_2O_5 \) was taken in a 1 L reaction vessel and allowed to undergo the following reaction at 500 K: \[ 2N_2O_5(g) \rightarrow 2N_2O_4(g) + O_2(g) \]
The total pressure at equilibrium was found to be 18.65 bar. Then, \( K_p \) is: Given: \[ R = 0.082 \, \text{bar L mol}^{-1} \, \text{K}^{-1} \]

Given below are two statements:
Statement I: The conversion proceeds well in a less polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{HO}^-} {CH}_3{CH}_2{CH}_2{CH}_2{OH} + {Cl}^- \] Statement II: The conversion proceeds well in a more polar medium. \[ {CH}_3{CH}_2{CH}_2{CH}_2{Cl} \xrightarrow{{R}_3{N}} {CH}_3{CH}_2{CH}_2{CH}_2{NH}_2 + {Cl}^- \] In the light of the above statements, choose the correct answer from the options given below:

Which of the following statement is true with respect to H\(_2\)O, NH\(_3\) and CH\(_4\)?
(A) The central atoms of all the molecules are sp\(^3\) hybridized.
(B) The H–O–H, H–N–H and H–C–H angles in the above molecules are 104.5°, 107.5° and 109.5° respectively.
(C) The increasing order of dipole moment is CH\(_4\)<NH\(_3\)<H\(_2\)O.
(D) Both H\(_2\)O and NH\(_3\) are Lewis acids and CH\(_4\) is a Lewis base.
(E) A solution of NH\(_3\) in H\(_2\)O is basic. In this solution NH\(_3\) and H\(_2\)O act as Lowry-Bronsted acid and base respectively.

Consider the given plots of vapor pressure (VP) vs temperature (T/K). Which amongst the following options is the correct graphical representation showing \( \Delta T_f \) depression in the freezing point of solvent in a solution?

Aman has been asked to synthesise the molecule:

Using an aldol condensation reaction. He found a few cyclic alkenes in his laboratory.
He thought of performing ozonolysis reaction on the alkene to
produce a dicarbonyl compound followed by aldol reaction to prepare "x".
Predict the suitable alkene that can lead to the formation of "x".

The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of

Preparation of potassium permanganate from MnO\(_2\) involves a two-step process in which the 1^st step is a reaction with KOH and KNO\(_3\) to produce:

The carbohydrates “Ribose” present in DNA is
A. A pentose sugar
B. Present in pyranose form
C. In “D” configuration
D. A reducing sugar, when free
E. In \( \alpha \)-anomeric form

Given below are two statements I and II.
Statement I: Dumas method is used for estimation of "Nitrogen" in an organic compound.
Statement II: Dumas method involves the formation of ammonium sulfate by heating the organic compound with concentrated H\(_2\)SO\(_4\). In the light of the above statements, choose the correct answer from the options given below:

Ksp for \( \text{Cr(OH)}_3 \) is \( 1.6 \times 10^{-30} \). What is the molar solubility of this salt in water?