PH Determination of Solutions - Lab Report Example

Chemistry Lab Report 30 April PH Determination of Solutions Introduction PH (potential hydrogen) may be defined as the concentration of hydrogen ions in a given solution (“PH as a Measure of Acid and Base Properties”). The pH of the solution enables it to be categorized as an acid or a base. The pH of a solution can be determined using a pH meter or universal indicator, which is a solution that displays various colors in solutions of varying pH. ObjectiveThe purpose of this lab was to investigate the outcomes of different indicators in testing for acids and bases.

Materials and Equipment1M acidic stock solution1M basic stock solutionUniversal indicator pH meterDistilled waterBeakersTest tubesProcedureThe 1M acidic and 1M basic stock solutions were diluted accordingly in five separate test tubes using distilled water. The five different acidic solutions were put in five test tubes and labeled accordingly as test tubes 0, 1, 3, 4, and 7. The pH of the solution in each test tube was then measured using a pH meter and the value was recorded. Thereafter, two to three drops of the universal indicator were added to the solution in each test tube and the resultant color was noted and read against the matching color and pH on the universal indicator chart.

A similar procedure was repeated for the basic solutions in four different test tubes labeled 10, 11, 13, and 14. The colors of the solutions and the resultant pH using the pH meter as well as the universal indicator were recorded and comparisons were made.Results In comparing the pH of various acidic and basic solutions using a pH meter and universal indicator, the color, pH of universal indicator and pH from the ph meter was recorded for each solution. Table 1 below summarizes the observed results for the acidic solutions.

Table 1: Color and pH of various acidic and basic solutions obtained using universal indicator and pH meterTest tube numberColorpH on universal indicator color chartpH on pH meter0PeachRed00.901Pale peachRed11.563Pale peachDark orange33.414YellowPale orange46.357Purple45.7710Pale orange54.2211PurpleYellow greenish611.213PurpleNavy blue1313.7214Light purpleDark blue1414Discussion and ConclusionIt was observed that the pH obtained from the pH chart varied from the pH obtained from the pH meter in most of the solutions.

The variations were small in some of the solutions such as1, 3 and 13. On the other hand, the variations in pH were significant in solutions such as 4, 7, 10 and 11. The pH meter value was the same as the universal chart pH in solution 14. The variations in the pH values can be attributed to the challenges in color interpretation when using the pH chart. Some of the resultant colors of solutions did not exactly match the color of the pH chart leading to the discrepancies in the pH values as the closest color was taken.

The slight variations in the pH chart values and pH meter values can be attributed to the sensitivity of the pH meter that allows it to quantify small changes in pH between 0.1 and 0.9. The pH chart, conversely, does not allow for the determination of pH values smaller than one unit. It was concluded that the pH meter was a more reliable tool than the pH chart in estimating the pH of acidic and basic solutions.Works CitedPH as a Measure of Acid and Base Properties 2002. Web. 30 April 2014. .