Solutions

Concentration Measurements

- solubility of gases DECREASES with INCREASING temperature (think: soda left out, flat tasting boiled water)

- unlike molaRity, molaLity does NOT change with temperature & pressure (also nearly the same b/c 1L = 1kg)

- mole fraction useful way to express concentration with more than 1 solute is present

Electrolytes

- ionizability factor (i) = tells us how many ions 1 unit of substance will produce in a solution (i=1, covalent and won't dissociate... i = > 1, a strong electrolyte)

7-3) concentration of bromide ions in solution --> concentration (M) = # molecules x molaLity (m)

**Memorize the Solubility Rules!

Phase Solubility Rules

1. The solubility of solids in liquids tends to INCREASE with INCREASING temperature.

2. The solubility of gases in liquids tends to DECREASE with INCREASING temperature.

- ex: soda outside, flat boiled water

3. The solubility of gases in liquids tends to INCREASE with INCREASING pressure.

7-6) Why choice C is the truth, and the above is applied:

Scuba diving safety: The most important issue here is that, in accordance with Henry's law, the increasing pressure correlates to increased absorption of nitrogen. Once the pressure decreases as you ascend, it takes that nitrogen time to get safely released from the body. If we ascend too quickly, the nitrogen bubbles can get too large to safely be eliminated through breathing, and that can have dire consequences (gas bubbles trapped in body). We'll discuss all this in some detail.