Lab Report On Red Cabbage Indicator

The experiment is to observe a variety of chemical reactions and to identify patterns in

Procedure: In this experiment, various chemicals were mixed together, to determine a reaction. Using two drops from chemical 1 and two drops of chemical two, unless otherwise stated, then recording the type of physical reaction or color changes that occurred.

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.

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).

There was an assortment of different changes indicating that chemical changes were taking place such as change in color or chemicals bubbling when combined with another chemical.

Bases are a substance with a pH higher than 7, and have a high concentration of hydroxyl ions. Bases can react with acids in order to neutralise them in order to form salt and water. Bases are normally metal oxides or metal hydroxides. Sodium hydroxide for example is a base.

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.

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

Hydrochloric acid is a strong acid whose pH is value is very close to 1. There is a measurement scale for the strength of acids which is called a pH scale, as the pH value gets closer to 1, it means the acid gets stronger. (pHScale, 2017) The chemical formula

There are five clues that help indicate if a chemical change occurs. The clues to a chemical change include a change of colour, the forming of a precipitate, the forming of gas bubbles, the production of heat or light, and if the change is difficult to reverse. In the chemical reactions lab, several chemical changes will occur. Participants must use this knowledge to decipher what change has occurred after the chemical

At station A when zinc and hydrochloric acid react with each other it is a chemical change because it creates gas bubbles and temperature change. At station B where NaOH solution and phenolphthalein react with each other it is a chemical change because it changed to the colour purple and the change looked difficult to reverse. Station C in which sulfuric acid and magnesium were to react with each other is a chemical change because it formed gas bubbles and changed colour. Station D where hydrochloric acid and Bromothymol blue were the materials is a chemical change because it changed to the colour yellow and looked difficult to reverse. In Station E where NaCl solution and AgNO3 solution were the materials is a chemical change because the reaction

Can red cabbage juice indicator be used to determine the strength of acids and bases? Explain.

The objective of this experiment, to determine the pKa of bromothymol blue, was accomplished spectrophotometrically. Bromothymol blue is a monoprotic acid (HIn), that is blue in basic solution and yellow in acidic solution:

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

I predict that out of the 20 solutions that we are going to be testing, about 6 of them will be an acid, 3 will be neutral and 11 will be a base.