pH scale from S2 Flashcards
What does the pH scale measure?
The acidity or alkalinity of a substance
What is the number range of the pH scale?
1-14
What is the colour range for the pH scale?
What is the pH range for acids?
Less than 7
Do strong acids have a higher or lower pH than weak acids?
Lower
What is the pH range for alkalis?
Greater than 7
Do strong alkalis have a higher or lower pH than weak alkalis?
Higher
What is the pH value for neutral solutions?
7
True or false? The pH scale can only measure in whole numbers.
False
What is an indicator?
A substance that changes colour to identify pH values
How do we test a substance for pH using universal indicator?
1. Substance must be in aqueous solution
2. Place a few drops of indicator solution into a small volume of the substance.
3. Compare and match the colour to appropriate colour chart
4. Read off correct pH value for that colour
What are some natural sources of indicators?
Plants, fruits and flowers
How do you make red cabbage indicator?
What is the colour scale for red cabbage indicator?
Name 3 indicators used in the lab
pH paper universal indicator red cabbage indicator