Chemical Kinetics

Q1.The units of rate constant for a zero order reaction are:

• As⁻¹
• Bmol L⁻¹ s⁻¹
• Cmol⁻¹ L s⁻¹
• Dmol⁻² L² s⁻¹

Q2.Show that time required for 99.9% completion of a first order reaction is 10 times the half-life. The ratio t(99.9%)/t₁/₂ equals:

• A5
• B7
• C10
• D3

Q3.For the reaction 2N₂O₅(g) → 4NO₂(g) + O₂(g), the initial concentration of N₂O₅ is 2.33 mol L⁻¹. After 184 minutes it becomes 2.08 mol L⁻¹. The average rate in mol L⁻¹ min⁻¹ is:

• A6.79 × 10⁻⁴
• B1.36 × 10⁻³
• C2.72 × 10⁻³
• D3.39 × 10⁻⁴

Q4.The decomposition of NH₃ on platinum surface at high pressure follows:

• AFirst order kinetics
• BSecond order kinetics
• CZero order kinetics
• DHalf order kinetics

Q5.The instantaneous rate of a reaction at time t is determined graphically by:

• AArea under the concentration-time curve
• BSlope of the secant to the concentration-time curve
• CSlope of the tangent to the concentration-time curve at time t
• DIntercept of the concentration-time curve