What is Ph?
Let's remember the previous topic
• What types of reactions in aqueous solutions do you know?
• What are indicators?
• What indicators do you know?
• How can you determine the reaction of aqueous solutions?
Answers
•
•
•
•
•
•
•
•
•
What types of reactions in aqueous solutions do you know?
neutral, alkaline and acidic.
What are indicators?
substances that can be used to determine the reaction of the
environment.
What indicators do you know?
in solutions: phenolphthalein, litmus, methyl orange.
dry: universal indicator paper, litmus paper, methyl orange paper
How can you determine the reaction of aqueous solutions?
wet and dry.
PH is a measure for determining the acidity
of aqueous solutions.
O
ACID
7
ALKALI
14
PH is measured on a range from 0 to 14, with 7 being a neutral pH,
values less than 7 indicating acidity, and values greater than 7
indicating alkalinity.
pH level is very important for our
body.
Blood PH=7.4
Acidosis
Blood pH drops below 7.4
Alkalosis
Blood pH drops below 7.4
In agriculture, soil
pH indicates which
crop is suitable for
growing it.
Rice , coffee , banana
Acidic soil
Grapes , cabbage
Alkaline soil
How to neutralize the soil?
soil acidity level for most plants ranges from 5.5-7.5
pH levels play an
important role in the
production of toiletries
. The pH level is usually
adjusted depending on
the hair type
Why are baby shampoos called
“no tears”?
Tears
What acid is found in our
stomach?
What happens if the pH
level drops?
How to help a person?
Tooth enamel is the hardest substance in our body .
It is insoluble in water and slightly acidic solutions,
however, when the pH level in the mouth drops
below 5.5, it slowly corrodes .
Why Ph level drops below 5.5 ?
When we eat food, some food particles remain
stuck to the teeth . Dental bacteria present in the
mouth produces acid due to the breakdown of
sugar and food particles present in the mouth,
which is what causes tooth decay .
Give some examples of how to avoid tooth decay
Methods for determining pH value
For definitions pH values of solutions wide use some techniques .
1. And indicators . What indicators do you know ?
2. universal indicator ( representing yourself mixture from several
indicators .)
3. device - pH meter
Laboratory work (pair work)
Topic: Research of soil
Answer the questions at home
• What pH values are typical for acidic, neutral and alkaline
environments?
• In what areas of science and production is it necessary to measure
the pH values of a solution of a substance? Give some examples.
• What is an indicator? How can we use it to determine the nature of
the environment?
• What are the advantages of a universal indicator?
• What is the name of the device for more accurately determining the
pH of the environment? Give its advantages.