List of top Chemistry Questions

For the cell Cu(s)|Cu$^{2+}$(aq) (0.1 M)||Ag$^+$(aq) (0.01 M)|Ag(s) the cell potential E$_1$ = 0.3095 V
For the cell Cu(s)|Cu$^{2+}$(aq) (0.01 M)||Ag$^+$(aq) (0.001 M)|Ag(s) the cell potential = ________ $\times 10^{-2}$ V. (Round off to the Nearest Integer).
[Use : $\frac{2.303 RT}{F} = 0.059$]

Given below are two statements :
Statement I : The limiting molar conductivity of KCl (strong electrolyte) is higher compared to that of $CH_3COOH$ (weak electrolyte).
Statement II : Molar conductivity decreases with decrease in concentration of electrolyte.
In the light of the above statements, choose the most appropriate answer from the options given below :

The product obtained from the electrolytic oxidation of acidified sulphate solutions, is :

The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric acid are 280, 860 and 426 S cm² mol⁻¹ respectively. The molar conductivity at infinite dilution of barium sulphate is ________ S cm² mol⁻¹. (Round off to the Nearest Integer).

The magnitude of the change in oxidising power of the MnO₄⁻ / Mn²⁺ couple is $ x \times 10^{-4} $ V, if the H⁺ concentration is decreased from 1 M to $ 10^{-4} $ M at 25 °C. (Assume concentration of MnO₄⁻ and Mn²⁺ to be same on change in H⁺ concentration). The value of $ x $ is __________ .

The resistance of a conductivity cell with cell constant 1.14 cm$^{-1}$, containing 0.001 M KCl at 298 K is 1500 $\Omega$. The molar conductivity of 0.001 M KCl solution at 298 K in S cm$^2$ mol$^{-1}$ is _________. (Integer answer)

The conductivity of a weak acid HA of concentration 0.001 mol L$^{-1}$ is $2.0 \times 10^{-5}$ S cm$^{-1}$. If $\Lambda_m^\circ(HA) = 190$ S cm$^2$ mol$^{-1}$, the ionization constant (K$_a$) of HA is equal to _________ $\times 10^{-6}$. (Round off to the Nearest Integer)

Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2.1 MPa to 1.3 MPa against at constant external pressure 4.3 MPa. The heat transferred in this process is ________ kJ mol⁻¹. (Rounded-off to the nearest integer) [Use R=8.314 J mol⁻¹K⁻¹]

At 298 K, the enthalpy of fusion of a solid (X) is 2.8 kJ $mol^{-1}$ and the enthalpy of vaporisation of the liquid (X) is 98.2 kJ $mol^{-1}$. The enthalpy of sublimation of the substance (X) in kJ $mol^{-1}$ is ________. (in nearest integer)

For the reaction $A_{(g)} \rightleftharpoons B_{(g)}$, the value of the equilibrium constant at 300 K and 1 atm is equal to 100.0. The value of $\Delta_r G^\circ$ for the reaction at 300 K and 1 atm in J mol$^{-1}$ is $-xR$, where $x$ is __________. (Rounded off to the nearest integer) [R=8.31 J mol$^{-1}K^{-1}$ and $\ln 10=2.3$]

Data given for the following reaction is as follows:
FeO(s) + C(graphite) $\rightarrow$ Fe(s) + CO(g)
The minimum temperature in K at which the reaction becomes spontaneous is _________. (Integer answer)

When 400 mL of 0.2 M H$_2$SO$_4$ solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution is ________ $\times 10^{-2}$ K. (Round off to the Nearest Integer).
[Use : H$^+$(aq) + OH$^-$(aq) $\rightarrow$ H$_2$O(l) ; $\Delta_r H$ = -57.1 kJ mol$^{-1}$
Specific heat of H$_2$O = 4.18 J K$^{-1}$ g$^{-1}$
density of H$_2$O = 1.0 g cm$^{-3}$
Assume no change in volume of solution on mixing.]

200 mL of 0.2 M HCl is mixed with 300 mL of 0.1 M NaOH. The molar heat of neutralization of this reaction is $-57.1$ kJ. The increase in temperature in $^\circ C$ of the system on mixing is $x \times 10^{-2}$. The value of $x$ is _________. (Nearest integer)
[ Given : Specific heat of water $= 4.18 \, \text{J g}^{-1} \text{K}^{-1}$
Density of water $= 1.00 \, \text{g cm}^{-3}$ ]
(Assume no volume change on mixing)

The reaction of cyanamide, NH$_2$CN(s), with oxygen was run in a bomb calorimeter and $\Delta U$ was found to be -742.24 kJ mol$^{-1}$. The magnitude of $\Delta H_{298}$ for the reaction NH$_2$CN(s) + 3/2 O$_2$(g) $\rightarrow$ N$_2$(g) + CO$_2$(g) + H$_2$O(l) is _________ kJ.

For water $\Delta_{vap}H=41$ kJ mol$^{-1}$ at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas that occupies a much larger volume than liquid water, the internal energy change during evaporation of water is __________ kJ mol$^{-1}$. (Nearest integer)
[Use: R=8.3 J mol$^{-1}$K$^{-1}$]

For the reaction C₂H₆ → C₂H₄ + H₂ the reaction enthalpy ΔH = _________ kJ mol$^{-1}$. (Round off to the Nearest Integer). [Given : Bond enthalpies in kJ mol$^{-1}$ : C-C : 347, C=C : 611; C-H : 414, H-H : 436]

The incorrect expression among the following is :

For water at 100$^\circ$C and 1 bar,
(Round off to the Nearest Integer)
[Use : R=8.31 J mol$^{-1}$ K$^{-1}$]
[Assume volume of H$\_2$O(l) is much smaller than volume of H$\_2$O(g). Assume H$\_2$O(g) can be treated as an ideal gas]

Assuming ideal behaviour, the magnitude of log K for the following reaction at 25 °C is $ x \times 10^{-1} $. The value of $ x $ is __________ . (Integer answer) $ 3\,\text{HC}\equiv\text{CH (g)} \rightleftharpoons \text{C}_6\text{H}_6 \text{ (l)} $ [Given : $ \Delta_f G^\circ (\text{HC}\equiv\text{CH}) = -2.04 \times 10^5 \,\text{J mol}^{-1} $; $ \Delta_f G^\circ (\text{C}_6\text{H}_6) = -1.24 \times 10^5 \,\text{J mol}^{-1} $; $ R = 8.314 \,\text{J K}^{-1} \text{ mol}^{-1} $]

The Born-Haber cycle for KCl is evaluated with the following data:
$\Delta_f H^\ominus$ for KCl = -436.7 kJ $mol^{-1}$; $\Delta_{sub} H^\ominus$ for K = 89.2 kJ $mol^{-1}$;
$\Delta_{ionization} H^\ominus$ for K = 419.0 kJ $mol^{-1}$; $\Delta_{electron gain} H^\ominus$ for $Cl_{(g)$ = -348.6 kJ $mol^{-1}$;
$\Delta_{bond} H^\ominus$ for $Cl_2$ = 243.0 kJ $mol^{-1}$.
The magnitude of lattice enthalpy of KCl in kJ $mol^{-1}$ is _________. (Nearest integer)}

The bond order and magnetic behaviour of O$_2^-$ ion are, respectively :

$AB_3$ is an interhalogen T-shaped molecule. The number of lone pairs of electrons on A is _________. (Integer answer)

Match List - I with List - II :

Choose the most appropriate answer from the options given below :

The compound/s which will show significant intermolecular H-bonding is/are :

The number of species having non-pyramidal shape among the following is _________.
(A) SO$_3$
(B) NO$_3^-$
(C) PCl$_3$
(D) CO$_3^{2-}$