Properties of Solutions
Solutions are homogeneous mixtures
A solute is the dissolved substance in a solution.
A solvent is the dissolving medium in a solution.
Salt in salt water
Sugar in soda drinks
Carbon dioxide in soda drinks
Water in salt water
Water in soda
“Like Dissolves Like”
Polar and ionic solutes dissolve best in polar solvents
Nonpolar solutes dissolve best in nonpolar solvents
The oxygen (slightly negative) end of the water molecule is attracted to the positive ion of a salt.
Water’s Solvent Interactions
The hydrogen (slightly positive) end of the water molecule is attracted to the negative ion of a salt.
The solubility of MOST solids increases with temperature.
The rate at which solids dissolve increases with increasing surface area of the solid.
The solubility of gases decreases with increases in temperature.
The solubility of gases increases with the pressure above the solution.
Solids tend to dissolve best when:
Ground into small particles
Gases tend to dissolve best when:
The solution is cold
Pressure is high
An electrolyte is:
A substance whose aqueous solution conducts an electric current.
A nonelectrolyte is:
A substance whose aqueous solution does not conduct an electric current.
Definition of Electrolytes and Nonelectrolytes
The ammeter measures the flow of electrons (current)
through the circuit.
If the ammeter measures a current, and the bulb
glows, then the solution conducts.