UNIT 1- The pH scale

Question 1

What is the pH scale?

Answer 1

pH scale measures how acidic or alkaline a solution is. Solutions have a pH between 1 and 14.

Question 2

What is an Acid?

Answer 2

Acids are a group of compounds with a pH less than 7. Acids are solutions which contain hydrogen ions (H+). Acids have a sour taste.

Question 3

What is an Alkali?

Answer 3

Alkalis are a group of compounds with a pH greater than 7. Alkalis contain hydroxide ions (OH-). Alkalis feel soapy to touch.

Question 4

How hazardous is a substance?

Answer 4

If an acid has a small pH, the more hazardous.
If an alkali has a large pH, the more hazardous.
The closer a pH value is to 7, the less hazardous a substance is.

Question 5

Describing Substances

Answer 5

We can described a substance with a pH lower than 7 as an acid or as being acidic.

We can described a substance with a pH greater than 7 as an alkali or as being alkaline.