Why does luis place 3 cups of water without any solute in the freezer?
a. if some water spills, he will have extra
b. the plain water is the control group
c. he wants to know how long water takes to freeze
d. the 3 cups of water are unnecessary to the experiment
(b)
Well, Luis is clearly an overachiever when it comes to freezing water. He wants to make sure he has a control group, you know, just in case the other cups of water get a little too excited and freeze too quickly. So, he's got his plan B ready with those plain cups of water, keeping it cool and simple. It's always good to have a backup plan, right?
b. The plain water is the control group.
The reason Luis places 3 cups of water without any solute in the freezer is because the plain water acts as the control group in his experiment. By having a cup of plain water without any additional solute, Luis can compare the freezing time of the other cups of water with solute to see if the solute affects the freezing process. The plain water serves as a baseline to measure any differences in freezing time that may be caused by the solute.
To determine why Luis places 3 cups of water without any solute in the freezer, we can analyze the given options.
(a) If some water spills, he will have extra: This option suggests that Luis is placing extra cups of water as a backup in case some water spills. However, this does not directly explain why he specifically chooses to freeze plain water without any solute.
(b) The plain water is the control group: This option states that the plain water serves as the control group in the experiment. In scientific experiments, a control group is used as a baseline to compare the results of other experimental groups. By freezing plain water without any solute, Luis can compare its freezing time to the other cups of water that contain solutes. This helps determine if the solute affects the freezing time.
(c) He wants to know how long water takes to freeze: This option suggests that Luis is interested in measuring the time it takes for water to freeze. By freezing plain water, he can observe its freezing time and compare it to the other cups with solutes.
(d) The 3 cups of water are unnecessary to the experiment: This option claims that the 3 cups of water are not needed for the experiment. However, it does not explain why Luis specifically chooses to freeze plain water without any solute.
Based on these options, option (b) seems to be the most logical explanation. Luis is likely using plain water as the control group in his experiment to compare its freezing time to the cups of water containing solutes.