Acids and pH in Plants and Digestion

What acid is found in the clouds of Venus?

What is the pH of the mouth needed to cause tooth decay?

What is the hardest substance in the human body?

What acid is produced in the stomach to help with digestion?

What is used to neutralize excess acid in the stomach?

Name a common base used as an antacid.

What acid is injected by a bee-sting?

What type of substance should be used to treat a bee sting?

What acid is injected by the stinging hairs of nettle leaves?

How can you prevent tooth decay, according to the text?

Acids in Other Planets

Venus' atmosphere is composed of thick, white, and yellowish sulfuric acid clouds.

Soil pH

Plants need a specific pH range for healthy growth.
Collect soil samples and test pH using a method described in Activity 2.12.
Note which plants grow in the collected soil region.

Activity 2.12

Put 2 grams of soil in a test tube and add 5 ml of water.
Shake the contents, filter, and collect the filtrate.
Check the filtrate's pH using universal indicator paper.
Determine the ideal soil pH for plant growth.

pH in the Digestive System

Hydrochloric acid (HCl) helps digest food without harming the stomach.
Excess stomach acid during indigestion causes pain and irritation.
Antacids, such as magnesium hydroxide (Milk of Magnesia), neutralize excess acid.

Tooth Decay

Tooth enamel (calcium hydroxyapatite) is a hard substance.
Tooth enamel erodes when mouth pH drops below 5.5.
Bacteria in the mouth produce acids by breaking down food particles.
Brushing with basic toothpaste neutralizes excess mouth acid, preventing decay.

Self-Defense Mechanisms (Animals & Plants)

Bee stings release acid, causing pain and irritation.
Baking soda (mild base) relieves bee sting pain.
Nettle leaves inject methanoic acid, causing burning pain.

This quiz explores the role of acids in various contexts, including the atmosphere of Venus, soil pH for plant growth, and the digestive system. Learn about the importance of maintaining the right pH levels for both healthy plants and proper digestion. Test your knowledge on the relationship between pH and tooth decay as well.