Lab Report Essay Example
Determining Acids and Bases With Homemade pH Indicator Strips Made With Red Cabbage Juice
Period 0 IB Chemisty
Annie Truong
Ms. Tran
Purpose: The purpose of this lab is to make homemade pH indicator strips using red cabbage juice as the main ingredient and estimate the pH of different substances with these strips.
Background Information: Acids and bases have properties of modifying the color of certain substances. The juice of the red cabbage is a blue-violet color and when it comes in contact with acidic substances it becomes red and when it comes in contact with basic substances it becomes green and sometimes yellow when it is very strong. A pH indicator is a halochromic chemical compound that is added in small amounts to a solution so that the pH of the solution can be determined visually. The pH indicator is a chemical detector for hydronium ions or hydrogen ions. The color of the solution to change depending on the pH. Red cabbage juice contains a natural pH indicator that changes colors according to the acidity of the solution. Red cabbage contains a pigmented molecule called flavin. Very acidic solutions will turn anthocyanin a red color. Neutral solutions result in a purple color. Basic solutions should appear greenish. Acids are substances which when added to water produces hydrogen ions and bases are substances which when added to water produces hydroxide ions.
Hypothesis: If I make a pH indicator strip using red cabbage juice as the main ingredient, then I can get an idea of what the pH level would be of different substances because the red cabbage juice contains a natural pH indicator that changes color according to the pH of the solution. The dependent variable would be the color of the cabbage paper and the independent variable would be the type of substance used. The control of this experiment would be the amount of cabbage juice and or substance.
Materials:
1. ½ of a red cabbage 2. 1 pot 3. 4 cups of water 4. 1
Period 0 IB Chemisty
Annie Truong
Ms. Tran
Purpose: The purpose of this lab is to make homemade pH indicator strips using red cabbage juice as the main ingredient and estimate the pH of different substances with these strips.
Background Information: Acids and bases have properties of modifying the color of certain substances. The juice of the red cabbage is a blue-violet color and when it comes in contact with acidic substances it becomes red and when it comes in contact with basic substances it becomes green and sometimes yellow when it is very strong. A pH indicator is a halochromic chemical compound that is added in small amounts to a solution so that the pH of the solution can be determined visually. The pH indicator is a chemical detector for hydronium ions or hydrogen ions. The color of the solution to change depending on the pH. Red cabbage juice contains a natural pH indicator that changes colors according to the acidity of the solution. Red cabbage contains a pigmented molecule called flavin. Very acidic solutions will turn anthocyanin a red color. Neutral solutions result in a purple color. Basic solutions should appear greenish. Acids are substances which when added to water produces hydrogen ions and bases are substances which when added to water produces hydroxide ions.
Hypothesis: If I make a pH indicator strip using red cabbage juice as the main ingredient, then I can get an idea of what the pH level would be of different substances because the red cabbage juice contains a natural pH indicator that changes color according to the pH of the solution. The dependent variable would be the color of the cabbage paper and the independent variable would be the type of substance used. The control of this experiment would be the amount of cabbage juice and or substance.
Materials:
1. ½ of a red cabbage 2. 1 pot 3. 4 cups of water 4. 1