Introduction to Solution chemistry

- A solution is a homogeneous mixture

- Solvents are components present in larger amounts

- Solutes are componets present in smaller amounts

- A solute is soluble in a solvent if it dissolves to form a homogenous mixture

- A saturated solution contains as much solute as possible

- An unsaturated solution can dissolve more solute

- Solubility is the measure of how much solute can dissolve in a given solution (g/L, g/ml, mol/L, ppm)

- The solubility of Ba (NO3)2in water is 63 g/100 mL @ 25 degrees Celcius while the solubilty of Ba(NO3)2 in alcohol is is 1.6 g/ 100 mL @ 25 degrees Celcius

Solubility is affected by:
1. heat
2. changing the solvent
3. changing the solute

- Measuring the conductivity of a solution

APRIL 14 CLASS NOTES

- Distilled water is non-conductive

- By adding salts, we increase the conductivity

- Electrical conduction in solutions requires charged ions to be present.
- Ionic solutions dissociate (break apart) when placed in water. Molecular solutions do not usually split into ions

Ex: Dissociation of sodium chloride:

NaCl --> Na + Cl

Steps to determine conductivity:

Follow these steps to determine if the solution is conductive:

Ask...

Is it a metal?
Yes = conductive. No ask...
Is it a solid non-metal?
Yes = non-conductive. No ask...
Is it an acid or base?
Yes = conductive. If noask...
Is it ionic?
Yes = conductive. no = non-conductive.

A chemical demonstration showing that ions must be present in solution for electrical conductivity