JEE Chemistry - MCQ Practice Questions

A reaction mechanism consists of: Step 1 (slow): A + B → C; Step 2 (fast): C + D → E. The overall reaction is A + B + D → E. What is the rate law?

For the equilibrium: H₂(g) + I₂(g) ⇌ 2HI(g), Kc = 50 at 400°C. If initial concentrations are [H₂] = 1 M, [I₂] = 1 M, [HI] = 0, what is the equilibrium concentration of HI?

What is the coefficient of x in the van 't Hoff equation: d(ln Kp)/dT = ΔH°/RT²?

The standard entropy change (ΔS°) for a reaction is -150 J/mol·K and ΔH° = -200 kJ/mol. Below what temperature will this reaction be spontaneous?

For a galvanic cell: Cu²⁺ + 2e⁻ → Cu (E° = 0.34 V) and Zn²⁺ + 2e⁻ → Zn (E° = -0.76 V). What is the standard cell potential (E°cell)?

Using Nernst equation at 25°C, if E°cell = 1.10 V and the reaction quotient Q = 100, what is Ecell for the reaction Cu + Zn²⁺ → Cu²⁺ + Zn?

What is the charge (in Coulombs) required to deposit 1 mole of Al from Al³⁺?

Which electrode reaction occurs at the anode in a galvanic cell?

For a weak acid HA with Ka = 1.8 × 10⁻⁵, what is the pH of a 0.1 M solution?

A buffer is prepared by mixing 100 mL of 0.2 M acetic acid with 100 mL of 0.2 M sodium acetate. What is the pH? (Ka of acetic acid = 1.8 × 10⁻⁵)

The solubility product (Ksp) of CaCO₃ is 3.3 × 10⁻⁹. What is the solubility of CaCO₃ in water?

A solution has [H⁺] = 1 × 10⁻⁷ M and [OH⁻] = 1 × 10⁻⁷ M at 25°C. Which statement is true?

For an endothermic reaction with ΔH = +150 kJ/mol and ΔS = +200 J/mol·K, above what temperature does the reaction become spontaneous?

A complex ion [Fe(CN)₆]³⁻ has a coordination number of 6. What is the oxidation state of Fe?

At 298 K, if ΔG° = -46.5 kJ/mol for a reaction, what is the equilibrium constant K? (R = 8.314 J/mol·K)

For the reaction: 2A(g) ⇌ B(g), Kp = 0.5 atm at 500 K. If initial pressure of A is 2 atm, what is equilibrium pressure of B?

The standard reduction potential for Zn²⁺/Zn is -0.76 V and for Cu²⁺/Cu is +0.34 V. Calculate E°cell for Zn-Cu galvanic cell.

Which factor does NOT affect the rate of a chemical reaction?

For a first-order reaction with half-life of 10 minutes, what percentage of reactant remains after 30 minutes?

The rate constant for a reaction increases by factor of 8 when temperature increases from 27°C to 47°C. Calculate activation energy (R = 8.314 J/mol·K).