Question

2.) use the following lab scenario to answer the questions below: a student wants to investigate if temperature affects how quickly sugar will dissolve in water. the student is going to do three trials at the following temperatures: 10 °c, 45 °c, and 100 °c. for each trial, the student is going to use 200 ml of water poured into the same 400 ml beaker. the student is going to add 25 g of sugar for each trial. in a fourth trial, the student will use normal water straight from the tap. the student will do each trial separately and record the time that it takes for the sugar to completely dissolve. a.) what is the independent variable? b.) what is the dependent variable? c.) formulate a hypothesis (if... then...): d.) what is the control group? e.) what are the experimental groups? f.) what variables are constants?

Explanation:

a. The independent variable is what the experimenter changes. Here, the student changes the temperature of the water.
b. The dependent variable is what is measured as a result of the change in the independent variable. The time for sugar to dissolve is being measured.
c. A hypothesis is an educated - guess. A possible one is based on the idea that higher temperatures speed up dissolving.
d. The control group is the group that serves as a standard for comparison. In this case, it's the trial with normal tap - water temperature.
e. The experimental groups are the ones where the independent variable is manipulated. Here, they are the trials at 10°C, 45°C, and 100°C.
f. Constants are variables that are kept the same throughout the experiment. The amount of water, amount of sugar, and the beaker are kept the same.

Answer:

a. Temperature of the water
b. Time it takes for the sugar to completely dissolve
c. If the temperature of the water is increased, then the time it takes for the sugar to dissolve will decrease.
d. The trial with normal tap - water temperature
e. The trials at 10°C, 45°C, and 100°C
f. Amount of water (200 mL), amount of sugar (25 g), and the 400 mL beaker