Physical Science / Unit 6: Solutions, Acids and Bases
6.4 Acids and Bases
Notes
- Acids produce hydrogen ions ($\text{H}^+$) in water. They taste sour, turn blue litmus red, and react with metals to release hydrogen gas. Examples: HCl, vinegar, citric acid.
- Bases produce hydroxide ions ($\text{OH}^-$) in water. They taste bitter, feel slippery, and turn red litmus blue. Examples: NaOH, soap, ammonia.
- Indicators like litmus, phenolphthalein and cabbage juice change color depending on acidity.
- Never taste lab chemicals. Strong acids and bases can burn skin.
Practice
Which ion do acids release in water?
Acids increase the hydrogen ion concentration.
A substance feels slippery and turns red litmus paper blue. It is most likely:
Slippery feel and turning red litmus blue are properties of bases.
Which is a base?
Ammonia solutions are basic.
Ready for more? Take the Unit 6 test.