Soru

Students conducted two experiments to study the decomposition of hydrogen peroxide ($H_2O_2$) into water and oxygen gas ($O_2$) in the presence of a yeast catalyst suspension.

Experiment 1
A test tube was filled with $10\text{ mL}$ of $3\%$ $H_2O_2$ solution. A yeast suspension with a concentration of $1.0\text{ g/L}$ was prepared. The students added $1\text{ mL}$ of the yeast suspension to the test tube at a temperature of $25^\circ\text{C}$ and measured the volume of $O_2$ gas produced over $5\text{ minutes}$. This procedure was repeated at temperatures of $35^\circ\text{C}$, $45^\circ\text{C}$, and $55^\circ\text{C}$.

Experiment 2
Using the same apparatus at a constant temperature of $35^\circ\text{C}$, the students added $1\text{ mL}$ of yeast suspensions of varying concentrations ($0.5\text{ g/L}$, $1.0\text{ g/L}$, $1.5\text{ g/L}$, and $2.0\text{ g/L}$) to separate test tubes, each containing $10\text{ mL}$ of $3\%$ $H_2O_2$ solution. The volume of $O_2$ gas produced was measured over $5\text{ minutes}$.

Based on the experimental designs described, is the statement that the concentration of the yeast suspension served as the independent variable in Experiment 1 and as a controlled variable in Experiment 2 true or false?