Pre-Class Monday 9-24-07 What does the word “equinox” mean? If you were not here on Friday, ask someone who was.

Pre-Class Thursday 10-17-13 You add a _____ to a ____ to make a solution. The maximum amount of a solute that can dissolve in a solvent is called _____, so the solution is _____.

Acids, Bases, and Salts Chapter 8

Acids A substance that produces hydrogen ions in a water solution When an acid is combined with water, hydrogen ions (H+) and hydronium ions (H3O+) are produced Have a sour taste Corrosive p258 Table 1 common acids and their uses

Bases A substance that forms hydroxide ions (OH-) in a water solution A substance that accepts H+ ions from acids Most bases are solids Feel slippery Bitter taste Corrosive p259 Table 2 common bases and their uses

How strong is the acid or base? If an acid (base) ionizes almost completely in water, then it is a strong acid (strong base). If an acid (base) only partially ionizes in water, then it is a weak acid (weak base). Measured using pH scale

pH Scale measures the amount of H+ ions produced ranges from 0 to 14 where < 7  acid = 7  neutral > 7  base A buffer can be used to hinder the change in pH of a chemical reaction.

This is the process when an acid and base cancel out. Neutralization This is the process when an acid and base cancel out.

What is the pH value for pure water? Pre-Class Friday 10-18-13 What is the pH value for pure water?

Indicator An organic compound that changes color in acid and base solutions For example, litmus paper will turn red in an acid and blue in a base

Salt A compound formed when the negative ions from an acid combine with the positive ions of a base Typically has a group 17 element (Halogens: “salt forming”) Common salts on p267 Table 3 Acid + base  salt + water

Titration Used to determine the concentration of an acid or base in a solution Compare the unknown solution with a standard (or known) solution An indicator helps by changing the color of the solutions as they mix The endpoint describes the point when the color no longer changes

Pre-Class Tuesday 03-11-08 The process where an unknown pH is found from a known pH? Neutralization Titration Precipitation Isolation