Solutions and solubility Flashcards
What is a solution
A homogenous mixture of 2 or more substances
Remains fuly mixed in same perportions
Liquid and gaseous solutions are transparent
solutions can be coloured or not
What is a solvent
any substance that has another substance dissolved in it.
It is the substance that is present in the largest amt
What is concentration
describes the ration of the quantity of solute to the quantity of solvent or solution
solid solid solution ex
alloys like
copper nickel
Solid liquid solution ex
sea water, salt and water
solid and gas solution ex
mothballs
liquid and solid solution ex
mercury and silver
Factors that affect the dissolving process (3)
Temp - for solid solutes they dissolve faster at higher temp
agitation - brings fresh solvent into contact with solute
lump or powder - size of particles changes rate of dissolve
How to write a dissociation equation
use only for ionic comp
solid on left ions it releases on right
do not include water
Example:
K3PO4(s) -> 3K+(aq ) + PO43- (aq)
Why do some molecular compounds dissolve in water and others dont. what are they called
dissolves in water - some can form hydrogen bonds ex. Glucose - miscible
Do not dissolve in water ex oil, hydrocarbons, They are non polar
Acetic acid can dissolve in both
What is a surfactant
it encourages oil and water to mix
has long hydrocarbon tail and charged head
One side attracts water, the other oil
surfactant surrounds oil and allows the water to wash it away
What affects solubility (4)
temp
Molecule size
ion carge
pressure
measured in
g/100g H2O
How is solubility measured
g/100g H2O
How does molecule size affect solubility
which extreme is more soluebl
small molecules are often more soluble than larger ones
ex methanol and ethanol are more soluble than pentanol
How does the ion charge affect solubility
ex, group 1 metals are soluble, sulfides are not
compounds with ions of smaller charges are more soluble
because the charge increases the force that holds the ions togethor
How does the ion size affect solubility
which extreme is more soluble
Small ions bond more closely than large ions
bonds between smaller ions are stronger
compounds with smaller ions tend to be less soluble
Metals have smaller ions than non metals
size gets bigger down a period
How does temperature affect solubility of solids gases and liquids
Solids - higher temp means more energy to break bonds
Gases - solubility of gases decreases with higher temp
liquid - temp does not affect solubility
How does pressure affect solubility
Pressure does not have an affect on solid and liquid
Solubility of gas increases as pressure increases
What are the degrees of saturation
Unsaturated - solution contains less than max quantity of solute
Saturated - solution contains max quantity of solute at a given temp
Supersaturated - Force a solution to siddlve more solute than it would normally.
(done by heating solution, dissolving solute then cooling)
How do you calculate concentration using molar concentration
c = q of solute / q of solution
measured in mol/L
c = n/v
Always convert to Liters
What is the dilution equation based off of c = n/v
C1V1 = C2V2
This is because when you dilute the solution the amt of moles stays the same.
What is the dilution factor
The concentration of the diluted solution divided by the concentration of the concentration solution
C2/C1
Multiply V2 by the dilution factor and you get V1
Qualitative analysis vs quant analysis
qual - the identification of the specific substances present
quant - the measurement of the quantity of a substance present
How does sequential chemical analysis work
To determine whether an element is present or not, a compound could be added to form a precipitate.
If nothing happens then the element was not present. If a reaction occurs then it was
done in a flow chart manner.
the precipitation formula must be stated
