A measure of
how much a
gas, liquid, or
solid becomes
dissolved in a
liquid.
MTBE: Methyl Tertiary Butyl Ether
A liquid that is very soluble in gasoline and used to
get more complete combustion of gasoline.
Unfortunately, also soluble in water. 42 g per liter.
Can be tasted at 0.0001 g / liter
Over 20,000 of these storage
tanks are estimated to be
leaking in Virginia
Salt (NaCl) is very soluble in water. 350 g/liter. However, if water
evaporates, there will be too much salt for the water to hold in solution.
The salt begins to form crystals.
A lake near Death Valley is supersaturated with salt
causing the salt to crystallize out.
Once a year the company who owns the lakes
lets visitors into the area to collect salt crystals.
These are some of the salt crystals collected.
Applications of Solubility
Knowledge
Cleaning
Separation (purifying)
Detection & Identification
Like dissolves like
• To dissolve grease,
use something that is
also greasy or oily.
Water: the Universal Solvent
One side of water is negatively charged
because the oxygen atom keeps the
shared electrons longer than the
hydrogen atoms. As a result the
oxygen side is negatively charged
and the hydrogen side of water is
positively charged.
O
Water: the Universal Solvent
Like a magnet that pulls on things that are magnetic, water pulls on things that are
electrically charged. Magnets have north & south poles, water has positive and
negative poles and thus called a polar solvent.
Since unlike charges attract, the negative end of water will be attracted to the positive
sodium ion. The positive end of water will be attracted to the negative chloride ion.
Since water is always in motion, it will pull on the ionic compound and move the ions
away from each other. This dissolves the ionic compound.
Na+
Cl-
Wax does not repel water
We’ve heard that wax or oils repel water. But that
isn’t true. Water is so attracted to other water
molecules that anything between them is squeezed
out of the way.
Oil
droplet
Water is always trying to pull itself into a tight
ball as long as there is nothing nearby that has
a charge on it. Therefore, this surface is not
repelling water; it’s simply not attracting it and
keeping water from doing what it does
naturally.
We see the same
effect on waxy
leaves.
Water pulls on itself so
much that it forms a
“skin.” It’s called
surface tension.
We are lucky that water has this strong attraction
force otherwise we’d never see raindrops. The
water would just breakup into a mist as it fell. Very
few liquids would remain as drops if they fell from
a large height.
Soaps & Detergents
Soaps and detergents are chains that have one end that is
like oil and has no charge and the other end is charged.
SO4SO4SO4-
Oil
droplet
SO4SO4SO4-
Acetone
O
CH3-C-CH3
• Solvent for fats, oils, waxes, resins,
rubber, plastics, varnishes, nail
polish remover, solvent for adhesives
& printing inks,
• Antiseptic solutions--to facilitate
penetration
• The evaporation rate of acetone
makes it quite useful for cleaning and
drying. It “dissolves” water so you
can wash away water allowing items
to dry faster.
Concentration of solutions
Approximate
Quantitative
Approximate Descriptions of
Concentration
Unsaturated
Saturated
Supersaturated
Dilute
Concentrated
This reference book indicates the solubility of many
inorganic and organic compounds.
Approximate
Guess what these abbreviations
stand for.
Click on them for answer.
water
alcohol
ether
acetone
benzene
Next Slide
ether very soluble in Ethanol
soluble in benzene
soluble slightly
in water
chloroform
Try to guess what these abbreviations mean and
then click on them for answers.
Chemical Abstracts Service
Quantitative Measurement of Concentrations
Mass Percent (w/w)
Mass/Volume (w/v)
solid mixtures/ solids in solvents
mg/mL, g/Liter
Medical solutions
g/100mL or g/100cc
Mass/Volume Percent (w/v)
Volume Percent (v/v) Liquid in liquid, liquors
Parts per million (ppm)
mg/liter (if water) wt or vol
Molarity (M)(mol/liter)
Trace amounts in water or air
Chemistry reagents
Mass/Volume (w/v)
These can be easily turned into Mass/Volume Percent (w/v)
Na3P
Saturated solutions
Mass/Volume Percent (w/v)
0.14 grams per 100 cc.
Many products list the concentration of their ingredients.
Fluoride is the active ingredient.
0.243 grams NaF per 100 cc.
0.15 grams Fluoride ion per 100 cc.
Insecticides are
often dissolved
in solvents.
Their
concentrations
are usually
given as sample
weight divided
by solvent
weight
converted to
percent.
For every 100 grams, how much of it is Diazinon?
Mass Percent (w/w)
Mass/Volume
Percent (w/v)
Grams
100 mL
5mg 100
1mL 100
.001
milli
=
Two ways of showing
concentration are given.
Let’s turn 5mg per mL into
0.5% to see they are the same.
0.5 g
100 mL
Mass/Volume Percent (w/v)
1% = 1g/100mL 0.2%= 0.2g/100mL
0.2%=0.2g/100mL
0.2g
15mL
= .03 grams
100mL
To calculate the grams of glycerin in this bottle use
dimensional analysis.
Mass/Volume
Percent (w/v)
50 g
1000 mL
0.1 =
5g
0.1
100mL
This lists the ingredients of Dextrose 5%. It says 50 grams
in 1,000 mL of water. The dimensional analysis above
shows how 50g per 1000mL can be converted to 5% (w/v)
Calculate Mass/Volume Percent (w/v)
Find grams per mL (divide 39g by 355mL)
39g = .11 g
355mL 1 mL
Multiply by 100 to get
grams per 100mL
.11 g 100
1 mL 100
Calculate the percent (w/v) of sugar.
= 11g = 11% (w/v)
100mL
% = ½ of proof
• Ionic Breeze® complies with U.S.
requirements for low ozone
emission (less than 50 parts per
billion)
O.S.H.A. 24 hour exposure limit,
0.05 PPM, {Parts Per Million}
The product lists 50 parts per billion (ppb) concentration of ozone.
OSHA, however, lists the level as 0.05 ppm. Let’s convert the ppm to
ppb to better compare these values.
After multiplying
by 1000 we find the
0.05
1000 =
50
0.05 ppm is the
1,000,000 1000
1,000,000,000
same as 50 ppb.
Quantitative Measurement of Concentrations
Mass Percent (w/w)
solid mixtures/ solids in solvents
Mass/Volume (w/v)
mg/mL, g/Liter
Medical solutions
g/100mL or g/100cc
Mass/Volume Percent (w/v)
Liquid in liquid, liquors
Volume Percent (v/v)
Parts per million (ppm)
Trace amounts in water or air
mg/liter (if water) wt or vol
Molarity (M)(mol/liter)
Chemistry reagents
You want to neutralize
360 grams NaOH
Reactants
•Weight
Convert
grams
to moles
Products
•Weight
How many grams of
HCl is needed?
Chemical reaction
Convert
moles to
grams
NaOH(aq)+ HCl(aq)  NaCl(aq) +HOH(l)
360 g NaOH
1 mole
40 g
=
9 moles NaOH
You want to neutralize
360 grams NaOH
Reactants
•Weight
Convert
grams
to moles
How many grams of
HCl is needed?
Chemical reaction
9 moles
Products
•Weight
Convert
moles to
grams
9 moles
NaOH(aq)+ HCl(aq)  NaCl(aq) +HOH(l)
9 moles HCl
36.5 g
1 mole
= 328.5 grams HCl
Reactants
Molarity = M
•Volume
•Concentration
1 mole
1M=
Liter
•Weight
Convert
volume
& Conc.
to moles
Products
If you had half a liter of 1M
For NaOH, 40 grams in
NaOH, how much 1M HCl is
one liter makes 1 M.
needed to neutralized it.
Chemical reaction
•Weight
•Volume
•Concentration
Convert
moles to
Volume
NaOH(aq)+ HCl(aq)  NaCl(aq) +HOH(l)
1M
1M
• Reactions go faster if the reactants are well mixed.
Dissolving them first in water and then mixing them
makes the reaction go faster.
Why are chemicals or drugs dissolved in water?
Concentration based on Moles per Liter
•
•
•
This bottle of Sodium Phosphate
lists the concentration as 0.1 M.
How many moles of sodium
phosphate are there in one liter of
this solution?
How many moles of sodium
phosphate in 3 liters?
How many moles in 0.1 liters?
• We’ve used silver nitrate to test
for chloride ion (Cl-) in a few lab
experiments.
 Ag+ + Cl-  AgCl(s)
• Silver nitrate dissolved in water is
a convenient way to add a small
amount of silver nitrate to
something else to see if a
reaction occurs with either the
silver or the nitrate.
• If this bottle is 250 mL, how many
moles of silver nitrate does it
contain? 250mL x 0.001
milli
=0.250 L
0.25L x 0.2 moles = 0.05 moles
1 Liter
• We’ve used silver nitrate to test
for chloride ion (Cl-) in a few lab
experiments.
 Ag+ + Cl-  AgCl(s)
A salt solution is 0.2 M NaCl.
How much of this salt
solution is needed to
precipitate all of the Ag+ from
this one liter bottle?
What if the NaCl solution was
0.4 molar? How much would
be needed?
Let’s say the left bottle is 4 liters. How many
moles of sodium arsenate are in a full bottle?
How much sodium arsenate would you weigh
out to make up 4 liters of this 0.1M solution?