6.1 Acids and Bases SNC2D

Properties of Acids Acids: taste sour taste sour

Properties of Acids Acids: taste sour taste sour are corrosive are corrosive (react with metals to produce hydrogen gas)

Properties of Acids Acids: taste sour taste sour are corrosive are corrosive (react with metals to produce hydrogen gas) release hydrogen ions (H + ) in solution (therefore, the physical state is always aqueous) release hydrogen ions (H + ) in solution (therefore, the physical state is always aqueous)

Examples of Acids acetic acid acetic acid HC 2 H 3 O 2 (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq) citric acid (in citrus fruit) citric acid (in citrus fruit) H 3 C 6 H 5 O 7 (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq) citric acid (in citrus fruit) citric acid (in citrus fruit) H 3 C 6 H 5 O 7 (aq) carbonic acid carbonic acid H 2 CO 3 (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq) citric acid (in citrus fruit) citric acid (in citrus fruit) H 3 C 6 H 5 O 7 (aq) carbonic acid (in soft drinks) carbonic acid (in soft drinks) H 2 CO 3 (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq) citric acid (in citrus fruit) citric acid (in citrus fruit) H 3 C 6 H 5 O 7 (aq) carbonic acid (in soft drinks) carbonic acid (in soft drinks) H 2 CO 3 (aq) hydrochloric acid hydrochloric acid HCl (aq)

Examples of Acids acetic acid (in vinegar) acetic acid (in vinegar) HC 2 H 3 O 2 (aq) citric acid (in citrus fruit) citric acid (in citrus fruit) H 3 C 6 H 5 O 7 (aq) carbonic acid (in soft drinks) carbonic acid (in soft drinks) H 2 CO 3 (aq) hydrochloric acid (in your digestive system) hydrochloric acid (in your digestive system) HCl (aq)

Naming Acids Binary acids (hydrogen + a single element) are called hydro_______ic acids e.g. H 2 S (aq) is hydrosulphuric acid

Naming Acids Oxyacids (hydrogen + a polyatomic ion) are called: _______ic acids if the name of the ion ends in -ate _____ous acids if the name of the ion ends in –ite e.g. HNO 3(aq) is nitric acid (NO 3 - is nitrate) HNO 2(aq) is nitrous acid (NO 2 - is nitrite)

The following steps should be followed when writing acid formulas. 1.Determine whether it is a binary acid or an oxyacid. If it is a binary acid, the name starts with hydro-. If it is a oxyacid, the name doesn’t start with hydro-. 2.Find the ion symbols and their charges using a periodic table and then cross over the charges.  If the oxyacid ends with -ic, the polyatomic ion’s name must end with -ate.  If the oxyacid ends with –ous, the polyatomic ion’s name must end with –ite. Writing Chemical Formulas

1.phosphoric acid a. does not start with hydro-, so it is an oxyacid b. look for the polyatomic that ends in –ate, since the acid name ends in –ic (phosphate) c. cross over the charges, H + PO 4 3- H 3 PO 4 (aq) Writing Chemical Formulas 2.hydrobromic acid a.starts with hydro-, so it is a binary acid b. look for the symbol and charges in the periodic table c. cross over the charges, H + Br - HBr (aq)

Properties of Bases Bases: taste bitter taste bitter

Properties of Bases Bases: taste bitter taste bitter feel slippery feel slippery

Properties of Bases Bases: taste bitter taste bitter feel slippery feel slippery are corrosive (break down proteins) are corrosive (break down proteins)

Properties of Bases Bases: taste bitter taste bitter feel slippery feel slippery are corrosive (break down proteins) are corrosive (break down proteins) release hydroxide ions (OH - ) in solution release hydroxide ions (OH - ) in solution

Examples of Bases Sodium hydroxide NaOH Sodium hydroxide NaOH Calcium hydroxide Ca(OH) 2 Calcium hydroxide Ca(OH) 2 Aluminum hydroxide Al(OH) 3 Aluminum hydroxide Al(OH) 3

Examples of Bases Sodium hydroxide NaOH Sodium hydroxide NaOH Calcium hydroxide Ca(OH) 2 Calcium hydroxide Ca(OH) 2 Aluminum hydroxide Al(OH) 3 Aluminum hydroxide Al(OH) 3 Sodium bicarbonate NaHCO 3 Sodium bicarbonate NaHCO 3 Ammonia NH 3 Ammonia NH 3

Copyright © 2010 McGraw-Hill Ryerson Ltd. The following steps should be followed when writing base formulas. 1.Use the periodic table and table of polyatomic ions to identify the symbols for the cation and anion in the base and their charges. 2.Cross over the charges. Writing Formulas for Bases e.g. : magnesium hydroxide Mg 2+ OH - Mg(OH) 2

Strong and Weak Some acids and bases are much stronger (have a higher concentration of ions in solution) than others. e.g.nitric acid is a strong acid; ammonia is a weak base