The document discusses pH scales, explaining that pH is a measure of how acidic or basic a solution is, with levels below 7 being acidic and above 7 being basic. It provides examples of the pH of different substances like vinegar, baking soda, and soap. The importance of pH for soil and personal care products is highlighted, noting that plants grow best in certain pH ranges and personal care products aim for specific pH levels to avoid harming the body.

1. Listen carefully in the discussion
Raise your hand if you want to recite
Participate and cooperate in every activities and
discussion
Avoid creating unnecessary noise
Refrain from always going out

2. LET’S START!

3. What is it like to eat a Calamansi?
What do we call the taste of a calamansi?

4. pH SCALE
LET’S LEARN ABOUT

5. Determine the pH of some given
solution
Give the importance of pH

7. In this activity, you will use the results in Activity 1, part B to
determine the pH of the solution you tested. Use the pH Scale in
your book, pp. 62-63. Present your results in the table similar to
this. ( 10 min.)
SAMPLE pH based on
Gumamela indicator
Acidic or Basic
vinegar red acidic

9. pH Scale
• 1. According to the data, what is the
pH range for an acid?
• 2. How about base, what is the pH
range?

10. SAMPLE pH based on
plant indicator
ACIDIC OR BASIC
Calamansi 2 Strongly acidic
Tap water 5-6 Weakly acidic
Distilled water Around 7 Neutral
Vinegar 2-3 Strongly acidic
Sugar in water 6-7 Basic
Baking powder Around 8 Basic
Softdrinks 2-3 Strongly acidic
Coconut water 5 Weakly acidic
Toothpaste 8-9 Basic
Shampoo 8-9 Basic
soap 8-9 basic

11. • The pH is a measure of how acidic (H+) or
basic (-OH) a solution is.
• A scale with values ranging from below 0 to
above 14 is used to measure pH.
Introduced by the Danish biochemist S.P.L. Sorensen.

12. • Substances with a pH
above 7 are basic. A base is
any substance that forms
hydroxide ions (-OH) in
water.
Ammonia (pH 11)

13. ►Substances with a pH
below 7 are acidic. An
acid is any substance that
forms hydrogen ions (H+)
in water.
vinegar

14. Did we Miss something??
• What happens when the pH of a substance
is 7?
Ans. A pH level of 7 indicates a
Neutral Substance

15. 0 1 2 3 5
4 7
6 8 1
0
9 1
1
1
2
1
4
13
NEUTRAL
ACIDIC BASIC/ALKALINE
•A scale with values ranging from below 0
to above 14 is used to measure pH.

18. SAMPLE MATTER pH
GASTRIC JUICE 1.6-1.8
LEMON JUICE 2.1-2.3
VINEGAR 2.4-3.4
SOFTDRINKS 5.5-7.0
RAINWATER ( UNPOLLUTED) 6.3-6.6

19. Get one copy of a picture and
place the pictures wherever
you think it belongs on the pH

20. Sample ph
Milk of magnesia Weakly basic
toothpaste weakly basic
tomato Weakly basic
apple Strongly acidic
cucumber Weakly basic
dove Weakly basic
Tap water neutral
medicine Weakly basic
Baking soda Weakly basic
muriatic Strongly acidic
Drain cleaner Strongly basic

21. milk Weakly acidic
Battery acid Strongly acidic
Bleach( zonrox) Strongly basic
coke Weakly acidic
grape Strongly acidic
lemon Strongly acidic
detergent Weakly basic
Fabric conditioner Weakly basic
Apple cider vinegar Strongly acidic
Orange juice Strongly acidic

22. safeguard Weakly basic
Rain water Neutral ( weakly acidic)
coffee Weakly acidc

23. How important is pH in:
• A. soil
b. Personal care products

24. Importance of pH…
• Soil
Some plants grow well in acidic soil while
others prefer basic soil. Farmers need to know
the pH of their soil since plants only grow in
narrow pH range.

25. Importance of pH….
• Personal care Products
– Most personal care products have pH kept at a
specific level to avoid harmful effects on the body.
– Example, on shampoos, at pH 12, hair already
dissolves, that is why hair removers have pH of
11.5-12.Most shampoos are within the pH range
of 4-6.

26. LET’S SUM UP….
 How do scientist measures the acidity and basicity
of a certain substance?
 What numbers on the scale mean acids?
 What numbers mean bases?

28. What is the effect of acidic
mixture in metal?