2.8 Classifying Inorganic Compounds (Section 8.1 pg )

So far, we’ve been generally looking at inorganic compounds– compounds that don’t contain a high % of carbon by weight. There are 2 main types of inorganic compounds (Fig.2 p.202):

Inorganic molecular compounds are molecules formed with 2 non-metals (but no C or very little C!). Common examples: water (H 2 O), ammonia (NH 3 ), CO 2 (counts as low % of C).

Inorganic ionic compoundsare divided into three categories: Acids, Bases and Salts. – Acids = any substance that releases H + ions in solution (they usually start with an H-) – Bases = any substance that releases OH - ions in solution. (They usually end in -OH) – Salts = any ionic substance that does not have an H + or OH - ion.

Chemical indicators are commonly used in labs to test for acids/bases (Table 2 p.203 & Data Pages

Please note H 2 O is basically composed of one H + ion and one OH - ion (Fig.4 p.204). Please read the section ‘Acidity’ on p.204 of your text – good info.

Acidity is a measure of the relative amounts of H + and OH - ions in solution (Table 4 p.205) – the higher the number of H + ions in solution the more acidic it is (opposite is true for basic solutions). Check out the pH scale in your Data Pages – gives examples of the pH of common solutions.

The pH scale is used to measure acidity (see Fig.6&8 p.205-6). On this scale acids have a pH 0-7, pH = 7 is neutral, and pH 7-14 is basic. The pH scale is logarithmic, meaning that every 1 point on the scale represents 10 times more or less acidity (see Table 5 p.206).

There are a separate set of rules for naming acids – please see the flow chart handout (Fig.9 p.207).

To name a base or a salt we follow the rules used for naming ionic compounds (Table 7 p.208).