During a recent lab activity, Carol Young’s Honors Chemistry students tested several types of solutions to determine pH — how acidic or basic the solutions are — and conductivity, i.e. how well the solutions conduct electricity). To do this, they used pH and conductivity sensors plugged into a Vernier digital interface.
The students found that chemical compounds, such as salts, that form electrolytes when dissolved in water had higher conductivity and more acidic pH’s. Compounds such as sugar that do not make electrolytes had lower conductivity and were less acidic. They were surprised to find that distilled water had a slightly acidic pH of 6 while hydrochloric acid was extremely conductive.