Free Chemical Equilibrium MCQs with Answers
625 Chemical Equilibrium MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Reversible reactions reach dynamic equilibrium when forward and reverse rates become equal, and Le Chatelier's principle predicts the effect of changing concentration, pressure or temperature. The chapter also covers solubility product, the common ion effect, buffer action and the conditions used in Haber's process, with equilibrium shifts distinguished from changes in the equilibrium constant.
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625 questions · page 4 of 32
- A. Yellow
- B. Light Yellow
- C. Brown
- D. Blue
Explanation: Silver iodide is a yellow precipitate because Ag+ reacts with I− to form the sparingly soluble compound AgI, which has a characteristic…
Correct answer: Yellow- A. Yellow
- B. Green
- C. Blue
- D. White
Explanation: Silver chloride forms a white curdy precipitate because Ag+ combines with Cl− to produce insoluble AgCl.
Correct answer: White- A. Alkali metals
- B. Aldehydes
- C. Halides
- D. Ketones
Explanation: Silver nitrate detects halide ions because Ag+ forms insoluble precipitates with Cl−, Br− and I−, allowing their presence and amount to be…
Correct answer: Halides- A. Hg, Pb
- B. Zn, Mn
- C. As, CD
- D. Cd , Pb
Explanation: Passing H2S precipitates both Hg2+ and Pb2+ as dark sulfides, so this pair is not readily distinguished by the colour of the initial H2S…
Correct answer: Hg, Pb- A. CuS
- B. CdS
- C. PbS
- D. AgCl
Explanation: AgCl is insoluble in nitric acid because its ionic lattice is not sufficiently broken by HNO3, whereas sulfides such as CdS and PbS…
Correct answer: AgCl- A. BaSO4
- B. SrSO4
- C. CaSO4
- D. MgSO4
Explanation: The solubility of alkaline-earth sulfates generally increases up the group, so MgSO4 is much more soluble in water than CaSO4, SrSO4 and…
Correct answer: MgSO4- A. saturated solution
- B. solubility
- C. unsaturated solution
- D. super saturated solution
Explanation: The concentration of solute present when a solution is in equilibrium with undissolved solid at a fixed temperature is its solubility.
Correct answer: solubility- A. KCIO4
- B. Na2SO4. 10H2O
- C. K2Cr2O7
- D. PbCl2
Explanation: Na2SO4·10H2O shows a discontinuity in its solubility curve because the decahydrate changes to another solid form at a transition…
Correct answer: Na2SO4. 10H2O- A. continuous and falling solubility curve
- B. discontinuous and falling solubility curve
- C. continuous and rising solubility curve
- D. discontinuous and rising solubility curve
Explanation: The solubility of KClO3 increases continuously as temperature rises because no solid-state transition interrupts the curve, and the…
Correct answer: continuous and rising solubility curve- A. Ka
- B. Kb
- C. Kc
- D. Ksp
Explanation: The solubility of a sparingly soluble ionic salt is determined from its solubility product, Ksp, using the ion concentrations in the…
Correct answer: Ksp- A. common ion effect
- B. solubility product
- C. dissociation constant
- D. dissociation constant for an acid
Explanation: For a sparingly soluble salt at equilibrium, the product of the molar concentrations of its ions, each raised to its stoichiometric power…
Correct answer: solubility product- A. NaCI
- B. Na2SO4
- C. Na2CO3
- D. FeCl3
Explanation: Na2CO3 gives CO3^2− ions, which react with water to produce OH− ions, making the solution basic.
Correct answer: Na2CO3- A. 2.0 x 10^-10 mol dm-3
- B. 1.414 x 10^-5 mol dm-3
- C. 1.0 x 10^-10 mol dm-3
- D. 1.0 x 10^-5 mol dm-3
Explanation: For AgCl(s) ⇌ Ag+ + Cl-, if the solubility is s mol dm-3, then [Ag+] = [Cl-] = s and Ksp = s2.
Correct answer: 1.414 x 10^-5 mol dm-3- A. dilute and concentrated
- B. dilute and saturated
- C. saturated and unsaturated
- D. saturated and super saturated
Explanation: A solution may be both dilute and saturated when the solute has low solubility: it contains only a small amount of solute, yet that amount…
Correct answer: dilute and concentrated- A. Increase the temperature
- B. Use a catalyst
- C. Adding more nitrogen gas
- D. Increase the pressure
Explanation: According to Le Chatelier's Principle, increasing the temperature will shift the equilibrium of the exothermic Haber process to the left…
Correct answer: Increase the temperature- A. BF3
- B. H+
- C. AlCl3
- D. H2O
Explanation: All the given options, BF3, H+, AlCl3, and H₂O, can act as Lewis acids since they can accept electron pairs.
Correct answer: H2O- A. Acetic acid & sodium acetate
- B. Acetic acid & ammonia
- C. Acetic acid and its ammonium acetate
- D. Ammonia & ammonium acetate
Explanation: .Acetic acid acts a good buffer with its salt because it is a weak acid.Acetic acid and sodium acetate form a buffer solution due to their…
Correct answer: Acetic acid & sodium acetate- A. pH = pKa + log [salt]/[acid].
- B. pH = pKa-log [acid]/[salt].
- C. pH = pKa - log [salt]/[acid].
- D. Pka =pH-log[salt]/[acid].
Explanation: The only incorrect form is:pH=pKa−log[salt]/[acid]
Correct answer: pH = pKa - log [salt]/[acid].- A. CH3COOH + CH3COONa
- B. H2CO3 + NaHCO3
- C. HCl + NaCl
- D. H3PO4 + Na2HPO4
Explanation: An acidic buffer solution is prepared by mixing weak acid and salt of it with a strong base.
Correct answer: HCl + NaCl- A. Reaction Mixture
- B. Reactants
- C. Equilibrium Mixture
- D. Products
Explanation: Le Chatelier's Principle describes how an equilibrium system responds to changes in temperature, pressure, or concentration.
Correct answer: Equilibrium Mixture