Red Cabbage Ph Indicator Lab

Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the chemicals are basic, acidic, or remain neutral when mixed with other chemicals.

“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

2. Four unknown samples were included in the lab kit: flax seed meal, potato starch, egg whites, and dried milk. Using the results of the biochemical testing, determine which number corresponds to the correct unknown. (8 points)

The objective of the Irresistible lab is to determine the capacity of each solution (unbuffered and buffered both) and how much they resist changes to pH. This is accomplished by having ten graduated beakers: two containing pure water, two with .1 M

Part two of the experiment focused on household items like food and cleaning products. It was interesting to see how different chemicals react with the bromthymol blue. The all purpose cleaner turned into a light yellow

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.

An acid is a chemical substance that typically has a corrosive or sour-taste and turns litmus paper red. It has a pH of below 7 and can generally dissolve some metals or even neutralize alkalis. A base on the other hand, is the opposite. They have a bitter taste and are very aqueous. Their pH rating is above 7 and they turn litmus paper blue. In science, pH is the negative log of the activity of the hydrogen ion in an aqueous solution. Basically, we find the pH of a substance by using a testing strip or litmus paper to see the amount of H+ atoms in it. Litmus paper, a common indicator, is used to easily test the pH level of a substance. We can see how acidic or basic a substance is by comparing it to others on a pH scale. A pH scale ranges from 0-14, the most acidic being 0 and most basic being 14. Lemon juice, for example, has a pH of 2 meaning its very acidic. However, average dish soap has a pH of 7-8. The only thing left is a pH level of exactly 7. A pH of 7 is perfectly neutral, not acidic or

In order for the media to show the change in acidity the solutions are modified and include an indicator chemical. This indicator will change color depending on the ph level of the media it is in. For all the media used in this experiment, the indicator changes to a yellow color when in the presence of an acid and turns magenta/pink when in the presence of a base or alkali.

An acid is a substance in solution which produces hydronium ions (H3O+) and is less than 7 on the pH scale. A base is a substance that produces the hydroxide ion (OH-) when in solution and is greater than 7 on the pH scale. Acids commonly have a sour taste, are corrosive, and conduct electricity in solution. Bases (or alkalis) have a soapy feel and a bitter taste, and also conduct electricity in solution. Neutral substances, however, do not have any of these properties, and are close to a 7 on the pH scale. The vegetable dye

The purpose of this experiment was to determine the pKa of the bromothymol blue (indicator) through absorption spectroscopy. Bromothymol blue being a monoprotic acid base indicator, displays different colors at different pH because of the differences in the ratio of the conjugated acid and base form. The fraction of conjugate acid and base was interpolated for the solutions through the acquired absorbance spectrum of the bromothymol blue at various pH. The rearranged form of Henderson Hasselbalch equation was graphed as a function of pH to determine the pKa of the indicator.

In this experiment, I learnt how to use litmus paper to determine the pH of gas. I also practised the titration process. During the experiment, I learnt to wet the litmus paper and then use tweezers to hold it to the neck to the bottle. The gas will dissolve in the water and change the colour of litmus paper. Besides, titration especially back titration is also learnt from this experiment. Some other variables can affect the result as well. Firstly, the range of methyl red is between 4.4(red) to 6.2 (yellow) which means when the indicator is orange, the pH of the solution is actually lower than 6.2, which means the acid is already too much when the solution turns orange. So if we can use a mixed indicator, the result might be more

The whole milk turned from a purple color to a yellow-orange color after it was boiled indicates small to moderate amount of

Some chemicals serve as indicators of how many H+ ions are in a substance. That is, they indicate whether a chemical is an acid or a base. There is such an indicator in red cabbage. My hypothesis is when I add vinegar, and lemon juice into the purplish cabbage juice the color will be a pinkish color. Procedures: • Peel off three or four strips of cabbage leaves and boil then for 10-15 minutes • Pour the purplish cabbage liquid through a strainer to get out small chunks of cabbage.

The purpose of this lab is to determine which pigments in a plant support or effect photosynthesis, based on starch production, which wavelengths of light are involved in photosynthesis, and identify plant pigments found in a plant leaf by means of paper chromatography.

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