pH of DYE | Science Experiment

by | Aug 4, 2022 | Chemistry, Science

Home » Science » pH of DYE | Science Experiment


In this experiment, we will determine the optimum pH of dye solutions that are fiber reactive for dying the 100% cotton cellulose fabric.


To determine the pH of dyes that could dye 100% cotton fabrics.


We hypothesize that the fiber reactive dye solution with high pH will give the cotton fabric a more intense color than the solution with low pH.


1. 6 Colors of dye

2. 54 cups

3. Distilled vinegar

4. Water

5. Sodium Carbonate solution

6. Litmus paper

7. Dichlorotriazine dye powder

8. 100% cotton cellulose fabric

9. Detergent

10. Tap water

11. Washing machine

12. Notebook


Step 1: Take six colors and prepare 54 cups of dye solution with a pH that ranges from 5 to 13.

Step 2: For preparing the solution with a lower pH, like 3, dissolve colors in vinegar and distilled water.

Step 3: To prepare the solution with a higher pH, like 13, dissolve sodium carbonate in water.

Step 4: Measure the pH of each solution with the help of a litmus paper.

Step 5: Add a measured amount of dichlorotriazine dye water to each of the solutions.

Step 6: Take a fabric prepared from 100% cotton cellulose. And using a scissor, cut 54 equal pieces from it.

Step 7: Soak each of these pieces into the previously prepared 54 cups solution of dye.

Step 8: After soaking them for several minutes, take them out and rinse them individually in tap water.

Step 9: Run them through a washing machine using a mild detergent.

Step 10: Carefully dry and mount them.

Step 11: Compare the intensity of each piece qualitatively and quantitatively.

Step 12: Record your observations.

pH of DYE | Science Experiment



1. From our experiment, we observed that the best and optimum pH for dyeing fabric of 100% cotton cellulose was 12.

2. The higher pH of the solution produced a more intense color than the lesser pH of the solution.


1. The hypothesis in which we assumed that the lesser pH would produce a less intense color than the higher pH solution was correct.

2. The chemical reaction that took place between the fabric and the dye enhanced more at a high pH than at a low pH.

3. The process of the reaction is that the carbon gets attacked by nucleophilic cellulose. The carbon was attached to one of the chlorine atoms of dichlorotriazine. The reaction displaced the chlorine and formed a covalent bond between dye and fiber.


1. Wear safety gloves and latex goggles while experimenting because of the sodium carbonate toxicity.

2. Record your observations.


In this experiment, we have determined the optimum pH of dye solution that can dye 100% cotton fabrics.

Viva Questions With Answers

Q.1 What was the aim of your experiment?

ANS. We aimed to determine the optimum pH of dye solution that can dye 100% cotton fabrics.

Q.2 Which pH of the solution proved optimum for dyeing?

ANS. The optimum pH for dyeing cotton fabrics was 12.


You May Also Like To Create…