List of top Chemistry Questions

In a colloidal solution, both the dispersed phase and dispersion medium are in liquid phase. What is the type of colloid?
In a first order reaction, the concentration of the reactant is reduced to 1/8 of the initial concentration in 75 minutes. The \(t_{1/2}\) of the reaction (in minutes) is (\(\log 2 = 0.30, \log 3 = 0.47, \log 4 = 0.60\))
Which of the following is used as froth stabilizer in froth floatation process?
The equation which represents Freundlich adsorption isotherm is (x = amount of gas, m = mass of solid)
White phosphorus on heating with concentrated NaOH solution in an inert atmosphere of CO\(_2\) gives a salt 'X' and gas 'Y'. The oxidation state of central atom in X and Y is respectively
The resistance of a conductivity cell filled with 0.1 M KCl solution is \(100 \, \Omega\). If the resistance of the same cell when filled with 0.02 M KCl solution is \(520 \, \Omega\), the molar conductivity of 0.02 M solution (in S cm\(^2\) mol\(^{-1}\)) is (Given: conductivity of 0.1 M KCl solution = \(1.29 \, \text{S m}^{-1}\))
1.95 g of non-volatile and non-electrolyte solute dissolved in 100 g of benzene lowered the freezing point of it by 0.64 K. The molar mass of the solute (in g mol\(^{-1}\)) (\(K_f(\text{C}_6\text{H}_6) = 5.12 \, \text{K kg mol}^{-1}\)) is
At 298 K, 0.714 moles of liquid A is dissolved in 5.555 moles of liquid B. The vapour pressure of the resultant solution is 475 torr. The vapour pressure of pure liquid A at the same temperature is 280.7 torr. What is the vapour pressure of pure liquid B in torr?
What are X, Y, Z in the following reaction sequence? But-2-ene \( \xrightarrow{X} \) Ethanoic acid \( \xrightarrow{Y} \) Ethanoyl chloride \( \xrightarrow{\text{Benzene, Anhy. AlCl}_3} \) Z
Which method is used to purify liquids having very high boiling points and liquids which decompose at or below their boiling point?
Among the following compounds, which one is not responsible for the depletion of ozone layer?
An element (atomic weight = 250 u) crystallises in a simple cubic lattice. If the density of the unit cell is \( 7.2 \, \text{g cm}^{-3} \), what is the radius (in \( \text{\AA} \)) of the atom of the element? (\(N = 6.02 \times 10^{23} \, \text{mol}^{-1}\))
Consider the following Statement-I : \( \text{Al}_2\text{O}_3 \) is amphoteric in nature. Statement-II : \( \text{Tl}_2\text{O}_3 \) is more basic than \( \text{Ga}_2\text{O}_3 \). The correct answer is
4 mL of 'X volume' \( \text{H}_2\text{O}_2 \) on heating gives 80 mL of oxygen at STP. The value of X is
Identify the incorrect order against the stated property.
Compound 'X' is prepared commercially by the electrolysis of brine solution. Which of the following is not the use of 'X'?
At \(25 ^\circ\text{C}\), \(K_a\) of formic acid is \(1.8 \times 10^{-4}\). What is the \(K_b\) of \( \text{HCOO}^- \)?
At T(K), the following gaseous equilibrium is established. W + X \( \rightleftharpoons \) Y + Z The initial concentration of W is two times to the initial concentration of X. The system is heated to T(K) to establish the equilibrium. At equilibrium the concentration of Y is four times to the concentration of X. What is the value of \(K_c\)?
One mole of \( \text{C}_2\text{H}_5\text{OH(l)} \) was completely burnt in oxygen to form \( \text{CO}_2\text{(g)} \) and \( \text{H}_2\text{O(l)} \). The standard enthalpy of formation (\( \Delta_f H^\ominus \)) of \( \text{C}_2\text{H}_5\text{OH(l)} \), \( \text{CO}_2\text{(g)} \) and \( \text{H}_2\text{O(l)} \) is x, y, z kJ mol\(^{-1}\) respectively. What is \( \Delta_r H^\ominus \) (in kJ mol\(^{-1}\)) for this reaction?
For one mole of an ideal gas an isochore is obtained. The slope of the isochore is \(0.082 \, \text{atm K}^{-1}\). What will be its pressure (in atm) when the temperature is 12.2 K? (R = \(0.082 \, \text{L atm mol}^{-1} \text{ K}^{-1}\)).
Consider the following reaction A(g) + 3B(g) \( \longrightarrow \) 2C(g); \( \Delta H^\ominus = -24 \) kJ. At \(25 \, ^\circ\text{C}\) if \( \Delta G^\ominus \) of the reaction is -9 kJ, the standard entropy change (in JK\(^{-1}\)) of the same reaction at same temperature is
Consider the following A) 0.0025 B) 500.0 C) 2.0034 Number of significant figures in A, B and C respectively, are
The pair of molecules / ions with the same bond order value is
How many of the following molecules have two lone pairs of electrons on central atom? SF\(_6\), BF\(_3\), ClF\(_3\), PCl\(_5\), BrF\(_5\), XeF\(_4\), H\(_2\)O, SF\(_4\)
The correct order of the non-metallic character among the elements B, C, N, F and Si is