JEE Main Chemical Equilibrium — practice questions
117 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice JEE Main Chemical Equilibrium in the app →For the homogeneous gas-phase reaction $A_{(g)} + B_{(g)} \rightleftharpoons C_{(g)} + D_{(g)}$ at equilibriumLe Chatelier's principle says that if a system at equilibrium is disturbed, the system will shift in the direcFor the synthesis of ammonia $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$, increasing the pressure on the syAt a certain temperature, the equilibrium constant $K_c$ for $A \rightleftharpoons B$ is $4$. If the initial cFor the reaction $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$, the relationship between $K_p$ and $K_c$ is:At $25°C$, the ionic product of water $K_w = [H^+][OH^-] = 10^{-14}$. What is the pH of pure water at $25°C$?Rutherford's alpha-particle scattering experiment led to the conclusion that the atom:According to Bohr's postulate, the angular momentum of an electron in the $n$-th allowed orbit of a hydrogen-lThe radius of the $n$-th Bohr orbit of a hydrogen-like atom of atomic number $Z$ varies as:The total energy of an electron in the $n$-th orbit of a hydrogen atom is given by $E_n = -13.6/n^2\,\text{eV}The minimum energy required to remove an electron from the ground state of a hydrogen atom is:The kinetic energy of an electron in the $n$-th Bohr orbit of a hydrogen atom is related to its total energy $The Rydberg formula for the wavelength of radiation emitted when an electron in a hydrogen atom jumps from levWhich spectral series of hydrogen lies entirely in the ultraviolet region?The hydrogen spectral lines that lie in the visible region of the electromagnetic spectrum belong to the:The major shortcoming of the Rutherford atomic model was that it could not explain:For a hydrogen-like ion of atomic number $Z$, the ground-state energy is:An electron in a hydrogen atom undergoes a transition from $n = 3$ to $n = 2$. The energy of the emitted photoFor the reaction aA + bB ⇌ cC + dD at equilibrium, the equilibrium constant Kc is:For an exothermic reaction at equilibrium, increasing temperature will shift the equilibrium:Le Chatelier's principle states that a system at equilibrium responds to a stress by:For the reaction N2 + 3H2 ⇌ 2NH3, increasing pressure favours:Equilibrium constant of a reaction is INDEPENDENT of:Relation between Kp and Kc for a gas reaction with Δn_gas = change in moles of gas:For an endothermic reaction, increasing T shifts equilibrium:For dissociation of weak acid HA in water: HA ⇌ H+ + A-. Equilibrium constant is called:pH of a 0.01 M HCl solution:pOH of a solution with pH = 8.5 (at 25°C):Solubility product Ksp of AgCl is 1.6 × 10⁻¹⁰. Its solubility in pure water (mol/L):For a buffer solution containing weak acid HA and its salt NaA, the pH is approximately:At equilibrium for an exothermic reaction, increasing pressure (for gas reaction with Δn < 0):At 500 K, Kc for N2 + 3H2 ⇌ 2NH3 is 60 (in mol⁻² L²). Kp at 500 K (R = 0.0821):For weak acid HA with Ka = 10⁻⁵, [H+] in 0.1 M solution is approximately:Buffer capacity is maximum when:A weak base BOH has Kb = 1.8 × 10⁻⁵. pH of 0.1 M solution is approximately:Solubility of CaF2 in water (Ksp = 4.0 × 10⁻¹¹):For the reaction PCl5(g) ⇌ PCl3(g) + Cl2(g), if initial pressure of PCl5 is P0 and degree of dissociation is αFor the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), at equilibrium increasing pressure:If K = 1 for a reaction, the standard free energy change ΔG°:At 298 K, water has Kw = 10⁻¹⁴. Concentration of H+ in pure water:At equilibrium, the ratio of forward to reverse reaction rates:In a saturated solution of AgCl, [Ag+] = 1.26 × 10⁻⁵. If KNO3 is added (no common ion), solubility of AgCl:For the reaction H2(g) + I2(g) ⇌ 2HI(g) with Kc = 50 at 800 K, if [H2] = [I2] = 0.01 M initially, equilibrium Degree of dissociation α of weak acid HA (Ka = 1.8 × 10⁻⁵) in 0.01 M solution:According to VSEPR theory, the shape of a molecule is determined byThe hybridisation of carbon in methane (CH₄) isWhich molecule is non-polar despite having polar bonds?The bond order of the oxygen molecule O₂ (by molecular orbital theory) isA coordinate (dative) bond differs from a normal covalent bond in thatWhich species has sp hybridisation on the central atom?As bond order increases, bond lengthAn ionic bond forms byThe shape of NH₃ is pyramidal rather than planar becauseWhich has the highest dipole moment?Among the following, which is paramagnetic?Formal charge on an atom = Per NCERT §6.1, equilibrium in a physical or chemical process is best described as which kind?Per NCERT §6.1.5, equilibrium can only be attained under which condition?Per NCERT §6.3 eqn 6.4, for the reaction aA + bB ⇌ cC + dD, the equilibrium constant Kc is expressed as which?Per NCERT §6.3 eqn 6.8, if Kc is the equilibrium constant of a forward reaction, the equilibrium constant of tPer NCERT §6.3, if a balanced chemical equation is MULTIPLIED throughout by n, the new equilibrium constant eqPer NCERT §6.4.1 eqn 6.15, the relationship between Kp and Kc for a gaseous reaction is which?Per NCERT §6.4.1, for the reaction H₂(g) + I₂(g) ⇌ 2 HI(g), the relation between Kp and Kc is which?Per NCERT §6.4.1, for N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g), the relation between Kp and Kc is which?Per NCERT Problem 6.1, given [N₂] = 1.5×10⁻² M, [H₂] = 3.0×10⁻² M, [NH₃] = 1.2×10⁻² M at 500 K, what is Kc forPer NCERT §6.5, for the heterogeneous equilibrium CaCO₃(s) ⇌ CaO(s) + CO₂(g), the equilibrium constant Kp equaPer NCERT §6.5, why do pure solids and pure liquids NOT appear in the expression for the equilibrium constant?Per NCERT §6.4.1, the units of Kp for N₂O₄(g) ⇌ 2 NO₂(g) (when partial pressures are in bar) are which?Per NCERT §6.6.2, if the reaction quotient Q is LESS than the equilibrium constant K, the reaction proceeds inPer NCERT eqn 6.22, the relation between standard Gibbs energy change ΔG° and equilibrium constant K is which?Per NCERT §6.7, if ΔG° is negative for a reaction, the value of equilibrium constant K satisfies which?Per NCERT §6.6.1, if Kc > 10³, what does this magnitude indicate about the reaction at equilibrium?Per NCERT §6.8, Le Chatelier's principle states that a stress on a system at equilibrium causes the system to Per NCERT §6.8.2, for the equilibrium CO(g) + 3 H₂(g) ⇌ CH₄(g) + H₂O(g), an INCREASE in pressure (decrease in Per NCERT §6.8.3, adding an INERT gas (e.g. argon) at CONSTANT VOLUME to a gaseous equilibrium has what effectPer NCERT §6.8.4, for an EXOTHERMIC reaction, what is the effect of raising the temperature on the equilibriumPer NCERT §6.8.5, what is the effect of adding a CATALYST on the position of equilibrium and on K?Per NCERT §6.8.5 + Table 6.5, for N₂ + 3H₂ ⇌ 2NH₃ (ΔH < 0), the Haber process operates at moderately high tempPer NCERT Problem 6.10, given ΔG° = 13.8 kJ/mol at 298 K for glucose phosphorylation, the value of Kc is closePer NCERT Problem 6.5, given Kc = 3.75×10⁻⁶ at 1069 K for 2 NOCl(g) ⇌ 2 NO(g) + Cl₂(g), the value of Kp is cloPer NCERT §6.10.1, in the ARRHENIUS concept, an acid is defined as a substance which does which on dissolving Per NCERT §6.10.2, in the BRØNSTED-LOWRY concept, an acid is defined as which kind of species?Per NCERT §6.10.3, in the LEWIS concept (G.N. Lewis, 1923), a base is defined as which kind of species?Per NCERT §6.10.2, what is the conjugate base of the Brønsted acid HSO₄⁻?Per NCERT §6.10.2 + Problem 6.13, what is the conjugate acid of the Brønsted base NH₃?Per NCERT §6.10.2, the conjugate base of a STRONG acid is necessarily which kind of base?Per NCERT §6.11.1 eqn 6.28, the ionic product of water Kw = [H⁺][OH⁻] at 298 K has which value?Per NCERT §6.11.1, Kw varies with which physical variable, since it is itself an equilibrium constant?Per NCERT §6.11.2, the pH of a solution is defined as which expression?Per NCERT eqn 6.29, at 298 K, what is the value of pH + pOH for any aqueous solution?Per NCERT §6.11.2, the pH of a 10⁻² M HCl solution (strong acid, fully dissociated) is closest to which value?Per NCERT §6.11.2, the pH of a 10⁻⁴ M NaOH solution (strong base, fully dissociated) is closest to which valuePer NCERT §6.12.5 (common-ion effect), addition of CH₃COONa to a solution of CH₃COOH does what to the degree oPer NCERT §6.13 (Henderson-Hasselbalch, eqn 6.40-6.41), the pH of an acidic buffer is given by which expressioPer NCERT §6.13, when [salt] = [acid] in a buffer, the pH of the buffer equals which quantity?Per NCERT §6.13, a buffer made from acetic acid and sodium acetate (pKa ≈ 4.76) at equimolar concentrations giPer NCERT §6.13, a buffer made from ammonia and ammonium chloride (pKb ≈ 4.75; conjugate-acid pKa ≈ 9.25) at ePer NCERT §6.13, on DILUTING a buffer solution, what happens to the buffer pH (to first approximation)?Per NCERT §6.14, for a sparingly soluble salt MX(s) ⇌ M⁺(aq) + X⁻(aq) with molar solubility S, the SOLUBILITY Per NCERT §6.14, for a salt M₂X(s) ⇌ 2 M⁺(aq) + X²⁻(aq) of molar solubility S, the SOLUBILITY PRODUCT Ksp equaPer NCERT §6.14, for a salt A₂X₃(s) ⇌ 2 A³⁺(aq) + 3 X²⁻(aq) of molar solubility S, the SOLUBILITY PRODUCT Ksp Per NCERT §6.14, comparing the ionic product Qsp with Ksp, PRECIPITATION of the salt occurs under which conditPer NCERT §6.14, the SOLUBILITY of a sparingly soluble salt in the presence of a COMMON ION (e.g. AgCl in NaClPer NCERT §6.14 (definition), what is the molar SOLUBILITY S of barium sulphate at 298 K, given Ksp(BaSO₄) = 1For the reaction $N_2 + 3H_2 \rightleftharpoons 2NH_3$, the equilibrium constant is:Increasing pressure on the equilibrium $N_2 + 3H_2 \rightleftharpoons 2NH_3$ shifts it:The pH of a solution with $[H^+] = 10^{-3}$ M is:A buffer is made by mixing $0.1$ M acetic acid ($pK_a = 4.74$) with $0.1$ M sodium acetate. The pH is:For the reaction 2A + B ⇌ 3C + D, the equilibrium constant Kc is:In the synthesis of ammonia (N2 + 3H2 ⇌ 2NH3 + heat), increasing the TEMPERATURE will:In an exothermic reaction, as temperature INCREASES, the equilibrium constant Kc:According to the Bronsted-Lowry theory, an acid is:A solution with pH = 4 is:A BUFFER solution is best described as:A solution of NH4Cl (ammonium chloride) in water is:If the solubility of AgCl is s mol/L in pure water, then its Ksp is:Adding NaCl (sodium chloride) to a saturated AgCl solution will: