Chemistry - chapter 12

solution

a homogeneous mixture of 2 or more pure substances

solute

substance that is dissolved in another substance

solvent

a substance used to dissolve a solute

colloid

suspensions of particles larger than individual ions or molecules but too small to settle out by gravity, can be separated by ultra filtration or centrifugation

suspension

a heterogeneous mixture where the particles do not dissolve (turbid/unclear) and the particles can be seen by eye

tyndall effect

• the scattering of light when shown in a colloid or suspension

• the light hits the particle, causing it to scatter

unsaturated

less solute than can dissolve at that temperature in the solvent is dissolved

saturated

the solvent holds as much solute as possible at that temperature

supersaturated

• more solute is dissolved in the solvent than what is normally possible at that temperature

• the solution is unstable and prone to crystalization

solubility curve

a graph that plots the amount of solute added to 100g of solvent for a saturated solution

molarity/concentration (M)

• the most common way to describe the composition of a solution in a lab

• (moles solvent)/(liters solution)

dilution

concentrated solutions are diluted when mixed with water, so the correct concentration is able to be reached

volumetric flask

used to most accurately mix up specific solutions

what are three ways to speed up the dissolving process?

surface area - the smaller the particle the quicker it dissolves

agitation/stirring

temperature increase

surface area

• the smaller the particle, the quicker it dissolves

• smaller particles dissolve faster because there is more surface area in contact with the solvent

agitation

• stirring increases the rate

• movement of particles allows for more interactions with the solvent

temperature

• solutes dissolve faster in warmer temperatures

• temperature is a measure of molecular movement, more movement, more interactions with the solvent