lesson 4 Flashcards
What are indicators?
Compounds that reveal pH level with a change in colour
What does the pH scale indicate?
How acidic or basic a compound is
What is the general chemical formula structure for acids?
Starts with an H
What is the general chemical formula structure for bases?
Ends with an _OH
What is the risk associated with acids and bases?
They can be very dangerous and corrosive
True or False: You can identify an acid or base by touch or taste.
False
What do indicators do in relation to pH?
Change colour based on the solution they are placed in
What is the most common pH indicator?
Litmus paper
What colour does blue litmus paper indicate?
Basic (>7)
What colour does red litmus paper indicate?
Acidic (<7)
Fill in the blank: The pH of acids and bases cannot be determined by sight; it is measured by other chemicals called _______.
[indicators]
What does a pH meter measure?
The electrical conductivity of the solution
What colour does methyl red turn in an acidic solution?
Red
What colour does bromothymol blue turn in an acidic solution?
Yellow
What pH is indicated when phenolphthalein is pink?
Basic
What colour does indigo carmine turn in a basic solution?
Blue
What is a characteristic taste of acids?
Sour
If litmus paper turns red, what does this indicate?
Acidic solution
If litmus paper turns blue, what does this indicate?
Basic solution
What happens to litmus paper in an acidic solution?
Turns red
What happens to litmus paper in a basic solution?
Turns blue
What is the pH range for neutral solutions?
7
