Brief Introductions of PH Test Papers

 PH test papers are a “ruler” to test the pH of a solution, also called litmus paper. And have many kinds, such as pH health test strips.

 

What is pH test paper:

• There are three indicators of methyl red, bromocresol green, and thymol blue on the PH test papers, and they will change color according to certain rules in solutions of different pH values.
• PH test papers are popular. When testing the pH of the solution, use a clean and dry glass rod to test the liquid
• And drop it in the middle of the test paper, observe the color after the change is stable, and compare it with the standard color chart to judge the properties of the solution.
• When testing the pH of the gas, first wet the test paper with distilled water, stick it to one end of the glass rod
• And then send it to the mouth of the container containing the gas to be tested, observe the change of color, and judge the nature of the gas.

 What do ph test papers for:

Method 1: Detect the pH of the liquid

Preparation tools: test paper glass rod

1. When you need to test the pH of the solution, take a small piece of test paper on the watch glass or glass, and be sure to use a clean glass.

2. Then use a clean and dry glass rod to dip a little of the liquid you need to test on the middle part of the test paper.

3. It does not take a long time to observe his changes. After the color is stable, you can compare it with the standard colorimetric card
4. And then judge whether the solution is acidic or alkaline, that is, the nature of the solution.

How to use ph test papers:

Method 2: Detect the pH of the gas

Preparation tools: test paper distilled water glass rod

1. First, you need to use distilled water to soak your PH test paper strips, and then stick it to one end of your glass rod.

2. Send it near the mouth of the gas container you need to test.

3. After a while, you can observe his changes, and judge the nature of the gas according to his changes. The editor here reminds us that the test paper should not touch the edge of the container’s mouth.

What is the principle of pH test paper:

• The prototype of pH test paper, litmus paper, was discovered by Boyle by chance:
• During a tense experiment, splashed the violets in the laboratory with concentrated hydrochloric acid.
• Boyle, who loves flowers, hurriedly rinsed the smoking violets with water and put them in a vase.
• After a while, Boyle noticed that the deep purple violets had turned red. This strange phenomenon prompted him to conduct many experiments on the interaction of flowers and trees with acids and bases.
• From this, he found that most flowers and plants can change their color under the action of acid or alkali.
• Among them, the purple infusion extracted from litmus lichen is the most obvious.
• It turns red when it encounters acid, and blue when it encounters alkali.
• Taking advantage of this feature, Boyle soaked the paper with litmus infusion, and then baked it, which made the acid-base test paper commonly used in experiments – litmus paper.
• And there are three indicators on the ph test strips: methyl red, bromocresol green, and thymol blue. Methyl red, bromocresol green, thymol blue.
• And phenolphthalein will change color according to certain rules in solutions of different pH values.

There are more introduces about other products, like the material of centrifuge tubes, type of centrifuge tubes, etc.