pH Levels and Chemical Reactions

This video tutorial covers the basics of chemistry, focusing on ions, ionization, and the pH scale. It explains how ionization leads to the formation of ions, the role of hydrogen and hydroxide ions in determining acidity and alkalinity, and the significance of pH balance. The tutorial also discusses the properties of acids and alkalis, their chemical reactivity, and safety precautions when handling strong alkalis like lye. Finally, it provides review questions to reinforce understanding of the material.

What is an ion?

• A molecule with a balanced electrical charge

• A molecule that cannot split

• An atom or molecule with an unbalanced electrical charge

• An atom with no electrical charge

What does the pH scale measure?

• The density of a substance

• The color of a substance

• The acidity and alkalinity of a substance

• The temperature of a substance

What is the pH of pure water?

• 14

• 9

• 7

• 5

How much more alkaline is a pH of 9 compared to a pH of 7?

• 100 times

• 20 times

• 200 times

• 10 times

What is the effect of pure water on hair?

• It has no effect

• It makes hair oily

• It causes hair to swell

• It causes hair to shrink

What is the average pH of human skin?

• 7

• 5

• 3

• 9

What happens to litmus paper in the presence of an acid?

• It turns blue

• It dissolves

• It turns red

• It remains unchanged

What is a common use for sodium hydroxide?

• As a food additive

• In drain cleaners

• As a skin moisturizer

• In perfumes

What should you do to avoid eye contact with lye?

• Wear safety glasses

• Use a face mask

• Wear gloves

• Avoid using the product

What is the result of mixing acids and alkalis in equal proportions?

• They form a new acid

• They form a new alkali

• They neutralize each other to form water

• They explode