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# Explain the pH Change As the Cause Of Tooth Decay

Citric acid may be found in citrus fruits like oranges and lemons, tartaric acid in tamarind, malic acid in apples, lactic acid in milk and milk products, and hydrochloric acid in stomach secretions. Many bases, such as lime water, are also available. Many of these acids are utilised in our daily life, such as vinegar or acetic acid in the kitchen, boric acid in laundry, baking soda in cooking, and washing soda in cleaning. Many acids and bases that we do not use in our daily life, such as HCl, H2SO4, and NaOH, KOH, are used in labs and businesses. When these acids and bases are combined in the correct amounts, the neutralisation process produces salt and water. Natural salts such as NaCl and KCl can be found in saltwater and natural rock formations. In this part, we’ll study more about acid, base, and salt, as well as their properties.

### What is pH?

The negative logarithm of H+ ion concentration is used to calculate pH. As a result, the meaning of pH is justified as hydrogen power.

We know that acids and bases do not all react at the same pace with the same chemical substance. Some have a strong reaction, some have a mild reaction, and some have no reaction at all. We utilize a universal indicator to determine the strength of acids and bases quantitatively, which shows distinct colours at varying concentrations of hydrogen ions in solution. In general, the pH value of acids and bases is used to determine their strength quantitatively.

### pH Scale

A pH scale is a tool for measuring acids and bases. Doctors and scientists generally agree that maintaining a good pH balance is important for overall health. The food and drink you ingest determine the pH level, or possible level of hydrogen, in your body. The concentration of hydrogen ions determines the pH. On a scale of 0 to 14, this computation is made.

1. The pH of an acid is less than 7 (lower the pH higher the acidity).
2. The pH of a base is more than 7 (higher the pH higher the basicity).
3. Any substance with a pH of 7 is considered neutral.

A living creature can only tolerate a small range of pH changes; any further change in pH makes survival harder. For instance, in acid rain, the pH of the water is less than 7. It lowers the pH of river water when it pours into it, making aquatic life harder to survive.

We are all aware that our stomachs contain hydrochloric acid, which aids in food digestion. We experience a lot of pain and irritation when the stomach produces too much hydrochloric acid during indigestion. As a result, we commonly employ antacids or a weak base to raise the pH of the acidic stomach and therefore reduce pain.

When a bee stings us, we feel a lot of agonies because the bee injects methanoic acid into our bodies through its sting. As a result, we are often advised to apply baking soda or other mild bases to the surface in order to keep the pH stable.

### pH Change as the Cause of Tooth Decay

Enamel and dentine eventually deteriorate as a result of tooth decay. Acids are produced by bacteria acting on carbohydrates, softening or demineralizing the enamel. After eating, bacteria in the mouth produce acids by oxidizing sugar and food particles in the mouth. When the pH of the mouth falls below 5.5, tooth decay begins.

Dental plaque is formed when bacterial cells adhere to the teeth in addition to food particles. Saliva cannot reach the tooth layer to neutralize the acid because plaque coats the teeth. Brushing your teeth after eating reduces plaque before bacteria produce acids.

If you want to avoid tooth decay, your main focus should be on reducing the bacterial load in your mouth. Brushing and flossing eliminate the sticky bacteria buildup on the teeth (plaque). Antimicrobial mouth rinses (such as Listerine or Scope) are efficient at reducing bacteria in the mouth when used in conjunction with brushing and flossing. Many kinds of toothpaste contain bases that help to neutralize oral acid (The pH of toothpaste being about 8.0). As a result, brushing your teeth with toothpaste can help to neutralize excess acid in your mouth.

### Sample Questions

Question 1: Three test tubes have been given to you. One is filled with purified water, while the other two are filled with an acidic and basic solution, respectively. How will you know what’s in each tube if all you have is red litmus paper?

Place the red litmus paper in each test tube one at a time. A basic solution will be the one that turns red litmus blue. The acidic solution can now be tested using the blue litmus paper that has formed. The acidic solution is the one that causes the blue litmus paper to become red. And the solution will be neutral if it has no effect on any litmus paper (i.e distilled water).

Question 2: Which of the following is a Natural Acid  Hydrochloric acid (HCl), Citric acid, Sulphuric Acid (H2SO4)?

Citric Acid is a Natural Acid, whereas Hydrochloric Acid and Sulphuric Acid are Mineral Acid.

Question 3: What is used to differentiate between Acid and Base?

pH indicator is use to differentiate between Acid and Base.

Question 4: Which of the following is more acidic Solution 1 (pH 3), Solution 2 (pH 5), Solution 3 (pH 1)?

Solution 3 > Solution 1> Solution 2 . Solution 3 is most acidic because lower the pH higher the acidity.

Question 5: At which pH level does tooth decay starts?