Question
0 2 Some factors affect the rates of chemical reactions. 0 2 1 A student investigated the drochlorichanging the particle size of calcium carbonate on the rate of reaction with hydrochloric and Figure 3 shows the apparatus. Figure 3 Describe a method the student could use to produce ce valid results. [6 marks]
Answer
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Milo
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Answer
To produce valid results, the student should:1. Measure a fixed mass of calcium carbonate for each particle size.2. Measure a fixed volume of hydrochloric acid with the same concentration for each trial.3. Add hydrochloric acid to a conical flask.4. Add calcium carbonate to the flask and start the stopwatch immediately.5. Record the time taken for the reaction to complete.6. Repeat the experiment for each particle size and conduct multiple trials.7. Compare the reaction times to determine the effect of particle size on the reaction rate.8. Keep all other variables constant.
Explanation
## Step 1: Identify the variables involved in the experiment. The independent variable is the particle size of calcium carbonate, and the dependent variable is the rate of reaction with hydrochloric acid.## Step 2: Gather the necessary materials: calcium carbonate in different particle sizes (e.g., large chunks, small granules, and powder), hydrochloric acid, a stopwatch, a balance, a measuring cylinder, and a conical flask.## Step 3: Measure a fixed mass of calcium carbonate for each particle size using the balance. Ensure the mass is the same for each trial to maintain consistency.## Step 4: Measure a fixed volume of hydrochloric acid using the measuring cylinder. The concentration of hydrochloric acid should be the same for each trial to ensure a fair test.## Step 5: Add the hydrochloric acid to the conical flask.## Step 6: Add the calcium carbonate to the conical flask and immediately start the stopwatch.## Step 7: Observe and record the time taken for the reaction to complete. This can be determined by the cessation of gas bubbles or the complete dissolution of calcium carbonate.## Step 8: Repeat the experiment for each particle size of calcium carbonate to ensure reliability. Conduct multiple trials for each particle size to obtain average results.## Step 9: Compare the reaction times for different particle sizes to determine the effect of particle size on the rate of reaction.## Step 10: Ensure all other variables, such as temperature and concentration of hydrochloric acid, are kept constant throughout the experiment to produce valid results.#