Acids and Bases Flashcards
what is an acid
a substance that releases hydrogen ions (H+) into an aqueous solution (citric acid and hydrochloric acid)
what is a base
a substance that releases hydroxide ions (OH-) into an aqueous solution. (sodium hydroxide and caustic soda)
properties of acids
- corrosive
- reacts with some metals
- releases hydrogen gas and leaves a salt behind
- neutralised by bases (producing water and salt)
- turns blue litmus paper red
- conducts electricity
- has a sour taste.
properties of bases
- are caustic (can burn or destroy organic materials)
- has a soapy, slimy feel
- turns red litmus paper blue
- has a bitter taste
- conducts electricity
- neutralised by acids (producing water and salt)
what is the purpose of an acid-base indicator
To indicate the pH level of how alkaline or acidic a substance is.
what colour red litmus paper changes in the presence of acids, bases and neutral substances
Acids: stays red
Bases: turns blue
Neutral: stays red
what colour blue litmus paper changes in the presence of acids, bases and neutral substances
Acids: turns red
Bases: stays blue
Neutral: stays blue
Define the pH scale
a scale that measures the concentration of hydrogen ions (H+) in a solution.
On a pH scale, which numbers represent acids?
Less than 7
On a pH scale, which numbers represent bases?
More than 7
On a pH scale, which numbers represent neutral substances?
7
What does neutralisation mean?
When acids and hydroxide bases react, they produce water and a salt
three everyday examples of neutralisation reactions
Antacids, brushing your teeth and soil treatment.
