Question

A student went to the dentist and found out that he had a cavity. He always brushes his teeth twice a day, so he didn't understand how he got a cavity. The dentist told him that drinking things every day that are acidic, such as lemonade, can contribute to cavities. He didn't drink lemonade but does drink a variety of other drinks.

The next day he brought in a sample of each drink and asked his science teacher to borrow a pH probe to test each liquid. The pH of Drink A is 11.9, Drink B is 7.0, Drink C is 5.3, Drink D is 9.8, Drink E is 2.4. Explain which drink(s) the student should avoid if he wants to protect his teeth from further damage.



In your response, be sure to include:

1. an explanation of what pH measures

2. which drinks are acidic, basic, and neutral.

Answer 1

The drinks that the student should avoid - if he wants to avoid damage to his teeth - are drinks C and E, since they are acidic, according to their pH.

Step-by-step explanation:

pH measures the acidity or alkalinity of a solution, taking into account the amount of hydrogen ions present in it, and established on a scale that goes from 0 to 14.

In chemistry, pH is derived from the formula that indicates:

pH = - Log₁₀ αH⁺ , where α is the activity of hydrogen ions.

A solution with a pH of 7 is considered neutral, above this value it is an acidic solution and below this value it is called acidic.

According to this:

• Acidic drinks are: drink C (5.3) and E (2.4).
• The basic drinks are: drink A (11.9) and drink D (9.8).
• The neutral drink is the drink B (7), which corresponds to water.