pH Scale Flashcards
What is pH?
The measuring of how acidic or basic a substance is.
What does pH stand for?
Power of Hydrogen
OR
Potential of Hydrogen
What are the properties of acids?
- pH is below 7
- Breaks apart in water to form positive hydrogen ions (cation)
- Turns blue litmus paper red
- Phenolphthalein stays clear
- Tastes sour
- Good electricity conductors
- React with metals
What are the properties of bases?
- pH is above 7
- Breaks apart in water to form hydroxide
- Turns red litmus paper blue
- Phenolphthalein turns magenta
- Tastes bitter
- Slippery texture
What are the properties of neutral substances?
- pH is exactly 7
- No acidic or basic qualities
- Litmus and pH paper of any color does not change color
- Phenolphthalein remains clear
What is an indicator?
A substance that changes color depending on the pH of what it interacts with (except if it’s neutral).
What are examples of indicators?
- Litmus paper: If red, stays red in acid, turns blue in base. If blue, stays blue in base, and turns red in acid.
- Phenolphthalein: Stays clear in acid, turns pink in base
- pH paper: It changes color depending on the pH, and the color is compared to colors on the pH chart.
A scientist takes a dropper, fills it with bleach (pH of 12), and pours the small amount of liquid into a test tube containing phenolphthalein. What would happen during the chemical reaction?
The phenolphthalein would turn pink due to the bleach being basic.
What is alkalinity?
The strength of a base.
What is acidity?
The strength of an acid.
A student rubs a blue litmus paper with a stirring rod, tipped with an unknown liquid. The liquid turns the litmus paper red. Is it acidic or basic?
Acidic
A scientist dips a red litmus paper in an unknown liquid. However, the litmus paper remains the same color. Is it acidic or basic?
Acidic
A student rubs a pH paper with a stirring rod, tipped with an unknown liquid. The pH paper remains the same color. Is it acidic or basic?
Neither; it is neutral.
