Question detail

When investigating the effect of temperature on reaction rate, which variable should be controlled?

Try the question, check the answer, then read the explanation to understand the curriculum point.

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At a glance

MCQ

Type

practice

Style

Topic

A-level practical endorsement and required practical activities

Question

A. All of the above
B. Concentration of reactants
C. Type of reaction
D. Volume of reactants

Answer

All of the above

Explanation

The correct option is All of the above. All of the above is the best answer because it directly supports the AQA A-Level Chemistry objective to required practical 3: investigate how rate changes with temperature. This reasoning is anchored to A-level required practical activities in A-level practical endorsement and required practical activities, and it separates required practical from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.

Common mistake

Temperature and Rate of Reaction

Students often incorrectly assume that increasing temperature will always double the rate of reaction without considering the specific reaction conditions.

To accurately determine how rate changes with temperature, use the Arrhenius equation: k = Ae^(-Ea/RT). Substitute the activation energy (Ea), the universal gas constant (R), and the temperature (T in Kelvin) to find the rate constant (k). For example, if Ea = 50 kJ/mol, R = 8.314 J/(mol·K), and T = 298 K, then: 1. Convert Ea to J: 50 kJ/mol = 50000 J/mol. 2. Substitute: k = Ae^(-50000/(8.314*298)). 3. Calculate: k = Ae^(-20.12). 4. The final answer will give the rate constant k in appropriate units, showing how the rate of reaction changes with temperature. Keep the correction anchored to A-level required practical activities and the objective: Required practical 3: investigate how rate changes with temperature.

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