Answer :
To determine which of the three substances [tex]\( X, Y, \)[/tex] and [tex]\( Z \)[/tex] is a catalyst for the reaction [tex]\( A + B \rightarrow C \)[/tex], where the formation of product [tex]\( C \)[/tex] is evidenced by bubble formation, follow these experimental steps:
### Step-by-Step Experimental Design
#### Step 1: Control Experiment (Without Catalyst)
1. Prepare Reactants: Measure 10 mL of substance [tex]\( A \)[/tex] and 10 mL of substance [tex]\( B \)[/tex].
2. Mix Reactants: Combine the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] in a clean reaction vessel.
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form, indicating the formation of product [tex]\( C \)[/tex]. From the information provided, this time should be 20 seconds.
4. Note Down Results: This will serve as the baseline reaction time for the uncatalyzed reaction.
#### Step 2: Experiment with Substance [tex]\( X \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount (e.g., a few drops or a small, consistent amount) of substance [tex]\( X \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( X \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
#### Step 3: Experiment with Substance [tex]\( Y \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount of substance [tex]\( Y \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( Y \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
#### Step 4: Experiment with Substance [tex]\( Z \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount of substance [tex]\( Z \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( Z \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
### Analyzing the Results
- Catalyst Identification: A catalyst will decrease the reaction time compared to the control experiment (20 seconds). Identify which of the substances, [tex]\( X, Y, \)[/tex] or [tex]\( Z \)[/tex], results in a shorter reaction time indicating faster bubble formation.
- Validity: Conduct multiple trials for each substance to ensure consistency and accuracy of results.
- Negative Control: Ensure there are no other variables affecting the reaction by repeating the control experiment without catalysts between tests to validate consistent baseline measurements.
By carefully following these steps, you will be able to confirm which substance acts as a catalyst in the reaction [tex]\( A + B \rightarrow C \)[/tex].
### Step-by-Step Experimental Design
#### Step 1: Control Experiment (Without Catalyst)
1. Prepare Reactants: Measure 10 mL of substance [tex]\( A \)[/tex] and 10 mL of substance [tex]\( B \)[/tex].
2. Mix Reactants: Combine the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] in a clean reaction vessel.
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form, indicating the formation of product [tex]\( C \)[/tex]. From the information provided, this time should be 20 seconds.
4. Note Down Results: This will serve as the baseline reaction time for the uncatalyzed reaction.
#### Step 2: Experiment with Substance [tex]\( X \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount (e.g., a few drops or a small, consistent amount) of substance [tex]\( X \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( X \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
#### Step 3: Experiment with Substance [tex]\( Y \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount of substance [tex]\( Y \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( Y \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
#### Step 4: Experiment with Substance [tex]\( Z \)[/tex]
1. Prepare Reactants and Catalysts: Measure 10 mL of [tex]\( A \)[/tex], 10 mL of [tex]\( B \)[/tex], and an appropriate amount of substance [tex]\( Z \)[/tex].
2. Mix Reactants with Catalyst: Add the 10 mL of [tex]\( A \)[/tex] and 10 mL of [tex]\( B \)[/tex] to the reaction vessel, then add [tex]\( Z \)[/tex].
3. Record Reaction Time: Observe the reaction and record the time it takes for bubbles to form.
4. Compare Results: Compare the reaction time with the control experiment's reaction time of 20 seconds.
### Analyzing the Results
- Catalyst Identification: A catalyst will decrease the reaction time compared to the control experiment (20 seconds). Identify which of the substances, [tex]\( X, Y, \)[/tex] or [tex]\( Z \)[/tex], results in a shorter reaction time indicating faster bubble formation.
- Validity: Conduct multiple trials for each substance to ensure consistency and accuracy of results.
- Negative Control: Ensure there are no other variables affecting the reaction by repeating the control experiment without catalysts between tests to validate consistent baseline measurements.
By carefully following these steps, you will be able to confirm which substance acts as a catalyst in the reaction [tex]\( A + B \rightarrow C \)[/tex].
