control: set amount of salt, set amount of water
Independent variable: temp of water
dependent variable: time to disolve
check my thinking.
A chemistry student is conducting an experiment to determine if table salt will dissolve faster in hot water or room temperature water. He will use a set measurement of salt placed in 100mL of room temperature water and compare the results to the same amount of salt placed in 100mL of hot water to determine which dissolved at a faster rate.
Independent variable: temp of water
dependent variable: time to disolve
check my thinking.
The controlled variables in this investigation include:
1. Amount of salt: A set measurement of salt is used in both conditions (100mL of room temperature water and 100mL of hot water).
2. Type of salt: The same type of table salt is used in both conditions.
3. Volume of water: The volume of water used for both conditions is kept constant at 100mL.
4. Time: The researcher will measure the rate of dissolution at the same time intervals for both conditions.
5. Stirring method: The same stirring method is applied in both conditions to ensure consistency.
By controlling these variables, the researcher can isolate the effect of temperature on the rate of salt dissolution.