How to test the acidity and alkalinity of water at home? Does carbon dioxide have acidity and alkalinity?

Carbon dioxide is a colorless, tasteless and odorless gas at room temperature. Carbon dioxide is one of the carbon oxides, commonly known as carbonic acid gas, also known as carbonic anhydride or carbonic anhydride. Acidity and alkalinity are the characteristics of a substance in an acid-base reaction. Does carbon dioxide have acidity and alkalinity? How to measure the acidity and alkalinity of water at home? We will understand these common sense of life by opening the following content.

Contents of this article

1. How to test the acidity and alkalinity of water at home

2. Does carbon dioxide have acidity or alkalinity?

3. The difference between the acidity and alkalinity of shampoo

How to test the acidity and alkalinity of water at home

Take a piece of pH test paper, use a glass rod or clean chopsticks to dip a small amount of water and drop it on the test paper. After the color appears, immediately compare it with the standard colorimetric card. Acidity and alkalinity are the characteristics of substances in acid-base reactions. Acidic substances turn purple litmus solution red, and alkaline substances turn it blue.

Bronsted and Laurent believed that acids are proton donors, bases are proton acceptors, and there is a conjugated relationship between acids and bases. Therefore, acidity is the property of a substance that can donate protons to a base, and alkalinity is the property of a substance that can accept protons provided by an acid. Similarly, in this theory, we can quantitatively describe the strength of acids and bases. In addition, although some substances still do not meet the acid-base definition of this theory, they can still have acidity/alkalinity. For example, pure sulfur trioxide cannot donate protons, but it has strong acidity.

Lewis believed that acids are electron acceptors and bases are electron donors. This theory can explain the origin of the acidity and alkalinity of most substances and is extremely practical, but it cannot give a quantitative relationship between the strength of acidity and alkalinity, and sometimes the acidity and alkalinity cannot be compared. For example, boron trifluoride and boron trichloride are both strong Lewis acids, but in some acid-base reactions, boron trifluoride is more acidic than boron trichloride, while in other cases, boron trichloride is more acidic than boron trifluoride. The specific comparison of acidity and alkalinity is a major difficulty in the Lewis acid-base theory, and the later proposed HSAB has made up for this defect to a certain extent.

Is carbon dioxide acidic or alkaline?

Carbon dioxide has no acidity or alkalinity. Only substances with aqueous solutions can discuss acidity or alkalinity, so we will not discuss the acidity or alkalinity of carbon dioxide. Since it can be acidic when dissolved in water, people call it an acidic oxide. Carbon dioxide is a colorless, tasteless and odorless gas at room temperature. Carbon dioxide is one of the carbon oxides, commonly known as carbonic acid gas, also known as carbonic anhydride or carbonic anhydride. At room temperature, it is a colorless and odorless gas with a density slightly greater than that of air. It dissolves in water and produces carbonic acid. Solid carbon dioxide is commonly known as dry ice. It can absorb a lot of heat when it sublimates, so it is used as a refrigerant, such as artificial rain, and is also often used to create smoke in stage design.

The difference between the acidity and alkalinity of shampoo

1. Different PH values. As mentioned above, the PH value of weak acid shampoo is less than 7, while the PH value of weak alkaline shampoo is greater than 7. Their test results on PH test paper are also different. If the PH test paper turns red, it is a weak acid shampoo, and if it turns blue, it is a weak alkaline shampoo.

2. Suitable for different hair types. Weakly acidic shampoo is suitable for girls with neutral and dry hair, while weakly alkaline shampoo is suitable for girls with oily hair. On the other hand, girls with oily hair should solve the problem of oily hair as soon as possible, and should not use weakly alkaline shampoo for a long time, otherwise the normal oil protective layer on the hair will be destroyed.

3. Different market demands. Since most people have slightly acidic hair, the market demand for slightly acidic shampoo is greater than that for slightly alkaline shampoo.