List of top Chemistry Questions

3 moles of an ideal gas expands isothermally against a constant pressure of 2 Pascal from 20 L to 60 L. The amount of work involved is

An aqueous solution of CuSO4 solution is electrolyzed for 193 s with a current of 2.5 amp. Given that the atomic mass of Cu is 63.5 and $ F = 96500 $ coulombs, the amount of copper deposited at the anode is

Gold crystallizes in a face-centered cubic lattice with unit cell length of 4.07 Å. Relative atomic mass of gold is 197.0. The density of gold will be

For which of the following is the adsorption theory applicable?

3 moles of an ideal gas expands isothermally against a constant pressure of 2 Pascal from 20 L to 60 L. The amount of work involved is

A colloidal solution is subjected to an electric field. The colloidal particles move toward the anode. In the coagulation of this solution using NaCl, BaCl2, and AlCl3 separately, which one is the correct order of coagulation power?

An aqueous solution of NaOH was made and its molar mass from the measurement of osmotic pressure at 27°C was found to be 25 g mol$^{-1$.}
Calculate the percentage dissociation of NaOH in this solution.

Can sodium ethoxide and t-butyl chloride be used for the preparation of t-butyl ethyl ether? Give suitable explanation. Justify your answer by suggesting the appropriate starting material required for preparation of t-butyl ethyl ether.

Write IUPAC names of the following coordination compounds:
$[ \text{CoCl}_2(\text{en})_2]\text{SO}_4 $
(ii) $ \text{K}_3[\text{Fe}(\text{C}_2\text{O}_4)_3] $
(ii) Didentate ligand and Ambidentate ligand

Reactant ‘A’ underwent a decomposition reaction. The concentration of ‘A’ was measured periodically and recorded in the table given below:

Based on the above data, predict the order of the reaction and write the expression for the rate law.

The Lineweaver-Burk plot for an enzyme obeying the Michaelis-Menten mechanism is given below.

The slope of the line is $0.36 \times 10^2$ s, and the y-intercept is $1.20$ mol$^{-1}$ L s. The value of the Michaelis constant ($K_M$) is ________ $ \times 10^{-3} $ mol L$^{-1}$ (in integer). [Note: $v$ is the initial rate, and $[S]_0$ is the substrate concentration]

The expressions for the vapour pressure of solid ($ p_1 $) and vapour pressure of liquid ($ p_2 $) phases of a pure substance, respectively, are \[ \ln p_1 = \frac{-2000}{T} + 5 \quad {and} \quad \ln p_2 = \frac{-4000}{T} + 10 \] The triple point temperature of this substance is __________ K (in integer).

The ratio of the fundamental vibrational frequencies $ \left( \nu_{^{13}C^{16}O} / \nu_{^{12}C^{16}O} \right) $ of two diatomic molecules $ ^{13}C^{16}O $ and $ ^{12}C^{16}O $, considering their force constants to be the same, is ___________ (rounded off to two decimal places).

The specific rotation of enantiomerically pure (S)-2-butanol is $ +14^\circ $. The specific rotation of the enantiomeric mixture of 2-butanol obtained from an asymmetric reduction of 2-butanone is found to be $ +7^\circ $. The percentage of (R)-2-butanol present in the reaction mixture is ____________ (in integer).}

Partial hydrolysis of a pentapeptide yields all possible tripeptides and dipeptides. The dipeptides that are obtained upon hydrolysis are given below: Val-Ala Gln-His Phe-Val Ala-Gln
The total number of tripeptides obtained that contain ‘Ala’ as one of the amino acids is __________

Xe and F₂ in 1:1 molar ratio when mixed in a closed flask and kept in sunlight for a day, gave white crystals of a compound Q. Two equivalents of Q on reaction with one equivalent of AsF₅ gave an ionic compound X⁺Y^– with the cation having two Xe atoms. The total number of lone pairs present on the cation X⁺ is ___________ (in integer).

The reaction between H$_2$ (g) and I$_2$ (g) was carried out in a sealed isothermal chamber. The rate law for the reaction was found to be: \[ \text{Rate} = k[\text{H}_2][\text{I}_2] \] If 1 mole of H$_2$ (g) was added to the reaction chamber and the temperature was kept constant, then predict the change in rate of the reaction and the rate constant.

The standard potentials ($ E^\circ $) for the Fe$^{3+}$/Fe and Fe$^{3+}$/Fe$^{2+}$ couples are -0.04 V and +0.76 V, respectively.
Given: Faraday constant = 96500 C mol$^{-1}$
The value for $ E^\circ $ (Fe$^{2+}$/Fe) in V is ............... (rounded off to two decimal places)

Energy of the transition from $ n_h = 4 $ to $ n_l = 2 $ for hydrogen atom is $ E \times 10^3 $ cm$^{-1}$.
Given: Rydberg constant for hydrogen: $ 1.097 \times 10^7 \, {m}^{-1} $
Value of E is ............... (rounded off to two decimal places)

A non-volatile solute has a molecular weight of 180 g mol$^{-1}$. Assume that the solute does not associate or dissociate in water, and the boiling-point constant (ebullioscopic constant) of water is 0.51 K kg mol$^{-1}$.
The amount (in g) of solute added to 500 g of water to elevate the boiling point by 0.153 K is ............... (answer in integer)

Consider the two $ pK_a $ values of valine as 2.32 and 9.62. The isoelectric point (pI) of this amino acid is ....... (rounded off to two decimal places)

The mean energy of a molecule having two available energy states at $ \epsilon = 0 $ J and $ \epsilon = 4.14 \times 10^{-21} $ J at 300 K is ___________ $ \times 10^{-21} $ J (rounded off to two decimal places). [Given: Boltzmann constant $ k_B = 1.38 \times 10^{-23} $ J K$^{-1}$]

For the cell reaction, \[ Hg_2Cl_2 (s) + H_2 (1 \, {atm}) \rightarrow 2Hg (l) + 2H^+ (a=1) + 2Cl^- (a=1) \] The standard cell potential is $ \mathcal{E}^0 = 0.2676 $ V, and $ \left(\frac{\partial \mathcal{E}^0}{\partial T}\right)_P = -3.19 \times 10^{-4} $ V K$^{-1}$. The standard enthalpy change of the reaction ($ \Delta_r H^0 $) at 298 K is $ -x $ kJ mol$^{-1}$. The value of $ x $ is ___________ (rounded off to two decimal places). [Given: Faraday constant $ F = 96500 $ C mol$^{-1}$]

Consider a Carnot engine with a hot source kept at 500 K. From the hot source, 100 J of energy (heat) is withdrawn at 500 K. The cold sink is kept at 300 K. The efficiency of the Carnot engine is ___________ (rounded off to one decimal place).

The kinetic energies of an electron ($e$) and a proton ($p$) are $E$ and $3E$, respectively. Given that the mass of a proton is 1836 times that of an electron, the ratio of their de Broglie wavelengths ($\lambda_e / \lambda_p$) is ___________ (rounded off to two decimal places).