Polar ethanol molecule is dissolved by the polar water molecule. Ethanol remains intact.
Will s ugar dissolve in water?
Will petroleum dissolve in water?
Oil on water- 2 phases
Will ionic compounds conduct electric current when dissolved in water? Yes Why?
Electrolytes and Non-electrolytes Electrolytes: conduct an electric current when in the molten state or in aqueous solution. Ionic compounds Non-electrolytes do not conduct a current. Usually molecular compounds
Is sugar C 6 H 12 O 6 electrolyte?
Do all electrolytes conduct electricity to the same degree? Weak electrolytes: partially ionize in water and conduct electricity in solution poorly (ex. Ammonia) Strong electrolytes: fully ionize in water and conduct electricity in solution strongly(ex. NaCl).
Hydrate: A crystalline compound in which the ions are attached to one or more water molecules.
Example: CuSO 4 5H 2 O copper(II) sulfate pentahydrate
Analyzing Hydrates Simulation click on the link below: bowe/sections/projectfolder/flashfiles/stoic hiometry/empirical.html bowe/sections/projectfolder/flashfiles/stoic hiometry/empirical.html
Problem Calculate the percent by mass of water in washing soda (Na 2 CO H 2 O) % mass of H 2 O = MM water x100 % MM Hydrate Answer: 62.9%
Efflorescent Hydrates Hydrates that have high vapor pressures compared to water. When the vapor pressure of the surrounding is lower than the vapor pressure of the hydrate, the hydrate will lose its water; it effloresces.
Hygroscopic Hydrates and Dessicants Hydrates that have a low vapor pressure compared to water. These hydrates can absorb water from the air. These can be used as dessicants (ex. CaSO 4 ).
Deliquescent Materials that absorb so much water that they will become wet (form solutions). Ex. NaOH.
Part II Heterogeneous Aqueous Systems
Colloids and Suspensions Heterogeneous Mixtures
Suspension A mixture whose particles are temporarily suspended in a medium, but eventually settle down. Particle size>100nm Ex: dust in air.
Colloid A mixture whose particles (of size ~1 to ~100nm) are dispersed through a continuous medium. (The word colloid means “glue-like”) Heterogeneous because there are distinct phases. Tyndall Effect: Scattering of light.
Types of Colloids Aerosol: liquid or solid in dispersed in gases (fog, smoke). Foam: gas in liquid (whipped cream). Emulsion: both substances are liquids (mayonnaise). Sol: solid in liquid (jelly)