List of top Chemistry Questions

One mole of \( PCl_5(g) \) was heated in a 1L closed flask at 500 K. At equilibrium, 0.1 mole of \( Cl_2(g) \) was formed. What is its \( K_p \) (in atm)? (Given R = 0.082 L atm mol\(^{-1} \) K\(^{-1} \))

At 300 K, the total pressure of the following system is 2 atm, at equilibrium: \[ \text{A}_2(g) \rightleftharpoons 2\text{A}(g) \] The atoms of A occupy 20% volume at STP. The \(K_c\) of the system is approximately (Given: R = 0.082 L atm mol\(^{-1}\) K\(^{-1}\), STP volume of 1 mole of a gas = 22.7 L)

Calculate the mole fraction of solute, if the vapour pressure of pure benzene at certain temperature is 640 mmHg and vapour pressure of solution of a solute in benzene is 600 mmHg.

Which one of the following is correct?

In \( A_3B \) crystal structure, A atoms occupied all octahedral as well as all tetrahedral voids and B atoms are at FCC centres. What is the formula of compound \( A_3B \)?

Which of the following molecules is not aromatic?

Which one of the following has the highest molar conductivity?

For an adiabatic change in a system, the condition which is applicable is

If the standard enthalpy of sublimation \( (\Delta_{sub}H^\circ) \) of solid \( CO_2 \), naphthalene, Li and Na are 25.2, 73.0, 162, 108 kJ mol\(^{-1} \) respectively, the order of sublimation of these substances with temperature is

Which one of the following options is correct for \[ q = -ve, \, w = +ve \{ (where \(q\) and \(w\) are heat and work respectively)} \]

Identify the correct statements from the following
(A) The compressibility factor (Z) for an ideal gas is 1
(B) Uranium isotopes (\( ^{235}U \) and \( ^{238}U \)) are separated by converting them into \( UF_6 \) vapours
(C) Decrease in temperature increases the kinetic energy of gas molecules

Which of the following reaction is not feasible?

When 3 moles of gas A is mixed with 1 mole of gas B at room temperature and 1 atm pressure, the entropy of mixing is
(Given log 3=0.4771,
log 4 = 0.6020)

Calculate the number of moles of carbon mono oxide in the following reaction
CH₃CH₂CHO \(\stackrel{hv}{→}\) CH₃CH₃ + CO
If the light irradiated has λ= 3020 A°, the quantum yield of reaction 0.54 and the light energy absorbed is 15000 erg in a given time.

Which of the following is more reliable?

The examples of chain silicate and sheet silicate respectively are

The conductivity of a solution containing 2.08 g of anhydrous barium chloride in 200 mL solution is $6 \times 10^{-3} \, \text{ohm}^{-1} \, \text{cm}^{-1}$. The molar conductivity of the solution (in $\text{ohm}^{-1} \, \text{cm}^{2} \, \text{mol}^{-1}$) is $x \times 10^{2}$. The value of $x$ is (Atomic mass of Ba = 137, Cl = 35.5)