Question

1. a student conducts an experiment to determine whether adding salt causes water to boil more quickly. the student plans to heat two pots of water and measure how long they take to boil. one pot has salt in it and the other does not. the pot of water with salt added is the experimental group. the pot of water without salt is the control group. for the boiling saltwater experiment described, list three things that would make the control group ineffective. (1 point)

Explanation:

In an experiment, the control group should be identical to the experimental group except for the variable being tested (in this case, salt). If the control group is different in other ways, it can't effectively show the effect of the variable. For example, if the pots are different sizes, the heat source is different, or the initial water volumes are different, these factors could influence boiling time instead of (or in addition to) the salt.

Answer:

1. Using a different - sized pot for the control group.
2. Having a different heat source (e.g., a weaker burner) for the control group.
3. Starting with a different volume of water in the control group.