ACIDS AND BASES
Acids are proton (hydrogen ion, H+) donors
Acids have a pH lower than 7
Acids taste sour
Acids effect indicators
Blue litmus turns red
Methyl orange turns red
Acids react with active metals, producing H2
Acids react with carbonates
Acids neutralize bases
Strong acids are assumed to be 100% ionized in solution (good H+ donors).
Weak acids are usually less than 5% ionized in solution (poor H+ donors).
Acids Have a pH less than 7
Citric acid in citrus fruit
Malic acid in sour apples
Lactic acid in sour milk and sore muscles
Butyric acid in rancid butter
Organic acids are weak acids. Some are used as flavoring agents in food.
Organic acids all contain the “carboxyl” group, sometimes several of them.
The carboxyl group is a poor proton donor, so ALL organic acids are weak acids.
Blue litmus paper turns red in contact with an acid.
Methyl orange turns red with addition of an acid
Acids react with active metals to form salts and hydrogen gas.
Mg + 2HCl MgCl2 + H2(g)
Zn + 2HCl ZnCl2 + H2(g)
Mg + H2SO4 MgSO4 + H2(g)
2HC2H3O2 + Na2CO3
2 NaC2H3O2 + H2O + CO2
Effects of Acid Rain on Marble (calcium carbonate)
HCl + NaOH NaCl + H2O
Neutralization reactions ALWAYS produce a salt and water.