ACT (Enhanced)ScienceMedium
A student is designing an experiment to investigate how the concentration of a salt solution affects the boiling point of water. They plan to prepare solutions with 0%, 5%, 10%, and 15% salt by mass. To ensure the reliability of their results, what is the most appropriate action the student should take?
- AVary the volume of water used for each solution.
- BUse different brands of salt for each concentration.
- CConduct multiple trials for each concentration.
- DOnly measure the boiling point once for each solution.
Show answer & explanationAnswer & explanation
Correct answer: C. Conduct multiple trials for each concentration.
Conducting multiple trials for each concentration allows the student to check for consistency in their measurements. If the results are similar across trials, it increases confidence in the reliability of the experiment. This helps identify and reduce the impact of random errors.
Why the other options are wrong
- A. Varying the volume of water would introduce another uncontrolled variable, potentially affecting the boiling point and making the results less reliable.
- B. Using different brands of salt would introduce another variable, compromising the experiment's control and making it harder to attribute changes to concentration alone.
- D. Measuring only once significantly reduces reliability, as a single measurement could be an outlier or contain significant random error.
Experimental Reliability
The extent to which an experiment, test, or any measuring procedure yields the same results on repeated trials.
- Indicates consistency and reproducibility of results.
- Achieved by repeating measurements or trials.
- Helps minimize the impact of random errors.
Memory trick: Reliable repetition yields robust results.