In the following data table of an experiment carried out at 4° C (39.2° F) over 4 hours, which of the following options represents the dependent variable?
Solution in bag
Solution outside bag
Bag mass change (g)
water
water
-0.2
20% sucrose
water
+2.4
40% sucrose
water
+4.3
60% sucrose
water
+5.8
A.
Duration
B.
Temperature
C.
Sucrose concentrations
D.
Bag mass change
The Correct Answer and Explanation is:
The correct answer is D. Bag mass change.
Explanation:
In an experiment, the dependent variable is the variable that is measured or observed in response to changes in other variables. It is the outcome that researchers are interested in understanding and is dependent on the manipulation of independent variables.
In the given experiment, the data table shows different solutions with varying sucrose concentrations and the corresponding change in bag mass over 4 hours at 4°C. Here’s how each option relates to the dependent variable:
- Duration: This refers to the length of time the experiment is conducted. In this case, the duration is constant at 4 hours for all experiments. Therefore, duration is not the dependent variable because it does not change; instead, it is a controlled condition.
- Temperature: The temperature is specified as 4°C (39.2°F) and remains constant throughout the experiment. Like duration, temperature is a controlled variable and does not change during the experiment, so it is not the dependent variable.
- Sucrose concentrations: This is the independent variable. The experiment tests solutions with different sucrose concentrations to see how they affect the outcome. The sucrose concentration is manipulated to observe its effect on the dependent variable, so it is not the dependent variable itself.
- Bag mass change: This is the dependent variable. The table shows how the mass of the bag changes for solutions with different sucrose concentrations. The change in bag mass is measured and observed in response to the varying sucrose concentrations, which is the main outcome of interest in this experiment.
In summary, the bag mass change is the outcome that depends on the sucrose concentration. As the concentration of sucrose in the solution changes, the bag mass change is recorded, demonstrating how the dependent variable (bag mass change) responds to variations in the independent variable (sucrose concentration). Therefore, the bag mass change is the dependent variable in this experiment.