Start learning →

CG PET Chemical Kinetics — practice questions

Explore 75 free Chemical Kinetics questions in CG PET Chemistry. Open each question or exercise to read its content, reference answers and available explanation.

Practise Chemical Kinetics with Quill →

Chemical Kinetics questions and exercises with answers

Showing questions 1–30 of 75.

The SI/CGS-style units of the **rate of a chemical reaction** are:Read the answer and worked solution →For the reaction A → B, the rate of reaction can be written as:Read the answer and worked solution →The **rate constant** $k$ in a rate law equals the rate of reaction when:Read the answer and worked solution →The order of a reaction:Read the answer and worked solution →For a zero-order reaction, the units of the rate constant $k$ are:Read the answer and worked solution →For a first-order reaction, the units of the rate constant $k$ are:Read the answer and worked solution →For the same reaction ($2N_2O_5 \to 4NO_2 + O_2$, $d[N_2O_5]/dt = -0.02$), the **rate of formation of $NO_2$** is:Read the answer and worked solution →If rate = $k[A][B]^2$, what are the units of $k$?Read the answer and worked solution →For the reaction A + B → P with $\text{rate} = k[A][B]^2$, rate = $3.6 \times 10^{-2}$ mol dm⁻³ s⁻¹ when [A] = 0.2 M and [B] = 0.1 M. $k$ equals:Read the answer and worked solution →For the reaction R → P, the *instantaneous* rate of reaction is given by:Read the answer and worked solution →For the reaction 2HI(g) → H₂(g) + I₂(g), the rate of reaction is:Read the answer and worked solution →The SI unit of rate of a reaction is:Read the answer and worked solution →The rate law for a reaction must be:Read the answer and worked solution →The units of the rate constant k for a zero-order reaction are:Read the answer and worked solution →The units of the rate constant k for a first-order reaction are:Read the answer and worked solution →A rate constant has units of L mol⁻¹ s⁻¹. The order of the reaction is:Read the answer and worked solution →For a zero-order reaction R → P, the integrated rate equation is:Read the answer and worked solution →For a first-order reaction, the half-life t_(1/2) is:Read the answer and worked solution →All radioactive decays follow which order of kinetics?Read the answer and worked solution →A first-order reaction with rate constant k = 5.5 × 10⁻¹⁴ s⁻¹ has a half-life of approximately:Read the answer and worked solution →For a chemical reaction, with a rise in temperature by 10°C, the rate of reaction typically:Read the answer and worked solution →The Arrhenius equation is:Read the answer and worked solution →On a plot of ln k versus 1/T (Arrhenius plot), what is the slope?Read the answer and worked solution →In the Arrhenius equation, the pre-exponential factor A is also called:Read the answer and worked solution →For a first-order reaction, the time required for 99.9% completion is approximately:Read the answer and worked solution →For a first-order reaction, if the initial concentration of N₂O₅ is 1.24 × 10⁻² mol L⁻¹ and after 60 min it is 0.20 × 10⁻² mol L⁻¹, the rate constant k is approximately:Read the answer and worked solution →For a zero-order reaction, if the initial concentration is doubled, the half-life:Read the answer and worked solution →Time required to decompose SO₂Cl₂ to half of its initial amount is 60 min. Assuming first-order kinetics, the rate constant is:Read the answer and worked solution →Rate of reaction is defined as:Read the answer and worked solution →Rate law: r = k [A]ᵐ [B]ⁿ. Sum m + n is called:Read the answer and worked solution →

Worked practice questions

The SI/CGS-style units of the **rate of a chemical reaction** are:

  1. L mol⁻¹ s⁻¹
  2. mol dm⁻³ s⁻¹
  3. mol L⁻¹
  4. s⁻¹
Show answer and solution

Correct answer: B. mol dm⁻³ s⁻¹

Rate = change in concentration / change in time, hence units are concentration/time = mol dm⁻³ s⁻¹ (or mol L⁻¹ s⁻¹).

Open this question →

For the reaction A → B, the rate of reaction can be written as:

  1. $-d[A]/dt$ only
  2. $+d[B]/dt$ only
  3. $+d[A]/dt = -d[B]/dt$
  4. $-d[A]/dt = +d[B]/dt$
Show answer and solution

Correct answer: D. $-d[A]/dt = +d[B]/dt$

A is consumed → rate $= -d[A]/dt$ (negative because [A] decreases). B is formed → rate $= +d[B]/dt$. By stoichiometry (1:1), both are equal.

Open this question →

The **rate constant** $k$ in a rate law equals the rate of reaction when:

  1. All reactant concentrations are zero
  2. All reactant concentrations are unity
  3. Temperature is zero kelvin
  4. Time is zero
Show answer and solution

Correct answer: B. All reactant concentrations are unity

Putting unit concentrations into rate = $k[A]^x[B]^y$ gives rate = $k$. **So $k$ is the rate at unit concentrations of all reactants.**

Open this question →

How to practise

  1. Choose a Chemical Kinetics question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Chemistry topics

Ideal and Non-Ideal SolutionsIdeal SolutionsNon-Ideal SolutionsReactions in Aqueous SolutionElectrochemistryElectrochemical SeriesCoordination CompoundsSolutions