TEACHER ENRICHMENT INITIATIVES

Activity 4B: Lab-pH of Common Foods

In Activity 4B students will determine the pH of common foods and food ingredients. Students will relate their results to the process of demineralization. Students will decide how their eating habits and dental hygiene habits can reduce demineralization. Acidic foods and food ingredients encourage demineralization. By using pH paper, the pH of common foods and food ingredients can be determined. By interpreting the pH, one can determine which substances increase the risk for tooth demineralization. 
 
The pH scale was developed by a bottling plant scientist who wanted to insure that the correct acidity was maintained for carbonated drinks produced by his plant. Now, this scale is used worldwide by scientists. The “p” stands for the mathematical value “power of ten.” The “H” represents the number of hydrogen ions or hydroxyl ions in a solution. The strength of an acid or base depends upon this number of ions. A neutral solution has a pH of 7, while acids are below 7 (0–6), and bases are above 7 (8–14). The official definition of pH is "the negative of the logarithm of the hydrogen ion concentration.”
 
Common Solutions and pH Values
pH
Solution
1
Hydrochloric Acid
2
Stomach Acid
3
Soft Drinks
4
Tomato Juice
6.5
Milk
7
Water, corn oil
11
Ammonia
13
Bleach
14
Sodium Hydroxide 

 

Keywords: 

Fluoride, fluoridation, pH, mathematical value, demineralization, oral health habit, sample preparation

 

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Activity Code: 
4B
Unit Reference: 
Watch Your Mouth
Lesson Reference: 
Lesson 4: Mineralization