Question

model 2 – results of alka-seltzer® experiment

	trial 1	trial 2	trial 3	trial 4	trial 5
volume of vinegar (ml)	100.0	100.0	100.0	100.0	100.0
room pressure (kpa)	84	84	84	84	84
initial temp (°c) vinegar solution	23.5	23.5	23.5	23.5	23.5
final temp. (°c) final mixture	22.6	21.5	20.4	19.2	18.1

1. which trial in the model 2 data table corresponds to the reaction illustrated in model 1?

1. consider the five trials that produced the data in model 2.

a. what variable was purposefully changed in the experiment?
b. what variable changed as a result of changing the variable listed in part a?

1. what variable(s) shown in the model 2 data table remained constant among all the trials?

Explanation:

Question 5

Step1: Analyze Model 1 (implied, likely reaction with Alka - Seltzer and vinegar, more tablets mean more reaction).

In Model 2, as the number of Alka - Seltzer tablets increases (from Trial 1:1, Trial 2:2, ..., Trial 5:5), the final temperature changes (decreases more? Wait, no, looking at final temp: Trial 1:22.6, Trial 2:21.5, Trial 3:20.4, Trial 4:19.2, Trial 5:18.1. So more tablets, more reaction (maybe exothermic/endothermic? But the key is that in Model 1, if it's about the reaction with varying tablets, Trial 5 has 5 tablets, which would have the most reaction. But the question is which trial in Model 2 corresponds to Model 1's reaction. Assuming Model 1 has a reaction with a certain number of tablets, but from the data, as the number of tablets increases, the final temperature decreases (more reaction, maybe endothermic). But maybe Model 1 has the maximum number of tablets? Wait, the table for Model 2: Number of Alka - Seltzer Tablets: Trial 1:1, Trial 2:2, Trial 3:3, Trial 4:4, Trial 5:5. So if Model 1's reaction is with 5 tablets (most), then Trial 5. But maybe I misread. Wait, the question is "Which trial in the Model 2 data table corresponds to the reaction illustrated in Model 1?". Since we don't have Model 1, but from the trend, as tablets increase, reaction extent increases. If Model 1 has the maximum reaction (most tablets), then Trial 5 (5 tablets) would correspond. But maybe the other way. Wait, maybe Model 1 has 1 tablet? No, usually more tablets mean more reaction. Alternatively, maybe the final temperature: if Model 1 has a certain final temp, but since we can only go by Model 2's data, and the number of tablets is the independent variable. So if Model 1's reaction is with, say, 5 tablets, then Trial 5. But maybe the answer is Trial 5? Wait, no, maybe I made a mistake. Wait, let's re - examine. The number of tablets: Trial 1:1, Trial 2:2, Trial 3:3, Trial 4:4, Trial 5:5. Volume of vinegar is constant (100 mL), room pressure constant (84 kPa), initial temp constant (23.5 °C). Final temp decreases as tablets increase. So if Model 1's reaction is with the most tablets (5), then Trial 5. But maybe the question is reversed. Alternatively, maybe Model 1 has 1 tablet, then Trial 1. But without Model 1, but from the data, the only variable changing is the number of tablets. So if Model 1 is a reaction with a specific number, but since we have to choose, maybe the answer is Trial 5? Wait, no, maybe I'm overcomplicating. Let's assume that Model 1's reaction is with 5 tablets (the maximum in Model 2), so Trial 5.

Step2: Confirm the correspondence.

Since the number of tablets is the manipulated variable, and as it increases, the final temperature (dependent variable) changes. So the trial with the number of tablets corresponding to Model 1's reaction. If Model 1 has 5 tablets, then Trial 5.

Step1: Identify the manipulated variable.

In an experiment, the variable that is purposefully changed is the independent variable. Looking at the Model 2 data table, the columns are: Number of Alka - Seltzer Tablets, Volume of Vinegar, Room Pressure, Initial Temp, Final Temp. The values for Volume of Vinegar (100.0 mL), Room Pressure (84 kPa), Initial Temp (23.5 °C) are constant across all trials. The number of Alka - Seltzer Tablets changes (1, 2, 3, 4, 5) across the trials.

Step2: Conclude the purposefully changed variable.

So the variable that was purposefully changed (independent variable) is the number of Alka - Seltzer tablets.

Step1: Identify the dependent variable.

The dependent variable is the variable that changes as a result of changing the independent variable (from part a, which is the number of Alka - Seltzer tablets). Looking at the data, the volume of vinegar, room pressure, and initial temperature are constant. The final temperature of the mixture changes (22.6, 21.5, 20.4, 19.2, 18.1 °C) as the number of tablets changes.

Step2: Conclude the changed variable.

So the variable that changed as a result of changing the number of Alka - Seltzer tablets is the final temperature of the mixture.

Answer:

Trial 5

Question 6a