Properties of Acids and Bases
Indicators
Indicators are substances that change color when the concentration of hydrogen changes. The choice of an indicator is dependent on the pH of the solution at the equivalence point. Common indicators include:
- Litmus paper - turns red in an acidic solution and blue in a basic (alkaline) solution
- phenolphthalein - colorless in acidic solutions and pink in alkaline solutions
- methyl orange - turns red in acidic solution and yellow in alkaline solutions
Litmus paper
Reactions
Neutralization occurs when an acid and a base combine to form a salt and water.
e.g. HCl(aq) + NaOH(aq) => NaCl(s) + H20 (l)
Acids and Metals is when reactive metals (those above copper in the reactivity series) produce a salt and hydrogen gas
e.g. 2HCl(aq) + Mg(s) => MgCl2(aq) + H2 (g)
Acids and Carbonates - acids react with carbonates, insoluble or soluble, to form a salt, carbon dioxide (CO2), and water.
e.g 2HNO3(aq) + Na2CO3(aq) => 2NaNO3(aq) + CO2(g) + H2O(l)
Bases and Ammonia (NH3) -
e.g. HCl(aq) + NaOH(aq) => NaCl(s) + H20 (l)
Acids and Metals is when reactive metals (those above copper in the reactivity series) produce a salt and hydrogen gas
e.g. 2HCl(aq) + Mg(s) => MgCl2(aq) + H2 (g)
Acids and Carbonates - acids react with carbonates, insoluble or soluble, to form a salt, carbon dioxide (CO2), and water.
e.g 2HNO3(aq) + Na2CO3(aq) => 2NaNO3(aq) + CO2(g) + H2O(l)
Bases and Ammonia (NH3) -
