Food Test Lab Report

“The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity (sic) of the solution. The letters pH stand for power of hydrogen and the numerical value defined as the negative base 10 logarithm of the molar concentration of hydrogen ions.” (PH, 2002). The pH scale is from 0 to 14. When the pH is higher, the hydrogen ions are fewer and the substance considered alkaline. This means when a pH unit increases by one, there is a tenfold change in the hydrogen ion. For example, if a substance has a 7 pH, it has 10 times as many as hydrogen ions available as 8 pH. A lake having a water pH between 6.5 and 8.5 is considered to be neutral. Researchers tested Peckham Park lake water monthly from August 2015 to April 2016 for water pH levels. A water quality PH test strip taken from a jar and dipped into the lake. After a few minutes, the strip will turn a color and this color determines the pH. The jar the strips came in has a chart of the colors on the back which compared to the color on the strip. The lake tested monthly using the PH test strips, which show the pH level, hardness, toxic, etc. using color-change

Acids are a corrosive substance with a pH less than 7. Acidity is caused by a high concentration of hydrogen ions.

To start out this study the difference between acids and bases has to be identified. Acids have very low pHs and have a high concentration of hydronium ions, while bases have a high pH and have a high concentration of hydroxide ions. The difference between strong bases and acids, and weak bases and acids is the amount of dissociation. Strong bases and acids dissociate a large amount and let go of their ions in solution, while weak bases and acids may only let go of some of their ions. This is important because if the unknown solutions aren’t strong acids or bases then using their ions to calculate the pH of the solutions will give false results (Diffen 2012).

Vinegar is a common household product, when mixed with the indicator, phenolphthalein, it turns pink. This indicates that Vinegar is acidic.

Neutralization reactions are those that involve the reaction of an acid and a base to form water and salt. A solution with a high hydrogen ion concentration is acidic, and a solution with a high concentration of hydroxide ions is

C.|NH3 + BTB|A4|The mixture is a lighter royal blue under white paper and a darker royal blue under black paper. The mustard yellow would be an acidic indicator and the royal blue a basic indicator. |

1. We measured 2 mL of diluted hydrogen peroxide (the substrate), 1 mL of guaiacol (the product indicator), and 1 mL of neutral buffer (pH 7) with a syringe and disposed it into tubes 1, 2 , 4, 9, 11, and 12.

The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.

weak bases). After ranking the pH of these solutions, you will then test your predictions in the laboratory.

By using acid-base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges for their color changes did not cover the equivalence points of the trials in which they were used. However, the

pH is a measurement of hydrogen ion concentration. It measures rather the solution is acid, base, or neutral.

6. Red cabbage juice is a natural, universal indicator. When a solution of red cabbage is red to pink, it indicates that a

Purpose/Hypothesis: The purpose of this experiment is to use both cabbage juice and pH paper to determine the pH of household items. This way, we can tell which products are basic and which one are acidic. If we use cabbage juice as an universal pH indicator by comparing it to pH paper then pH determined by the cabbage juice will be unstable because by using cabbage juice, it can be different depending on how diluted it is.

Table 2: Consists of color extract taken from a red cabbage for a natural indicator. The pH reading that was measured by using the pH meter and the result of the pH reading to determine whether the solution was acidic or basic.

Sodium hydrogen carbonate was added to the solution until it becomes neutral. Ph paper was used for this test to determine its ph value.