C2f: Acids and Bases
Acids, Bases and Indicators
Indicators are chemicals are chemicals that change colour to show changes in pH. Some indicators e.g litmus, have only 2 colours; others e.g universal indicator, have a range of colours over different pH values. Acids are substances with a pH of less than 7. BASES are the OXIDES and HYDROXIDES of metals with a pH of greater than 7.
ACIDS turn litmus paper red and BASES turn litmus indicator blue.
SOLUBLE BASES and called ALKALIS
METAL OXIDES and HYDROXIDES are bases. When they are added to acids in the correct amounts they cancel each other…