Dilution Formula : C1V1 = C2V2
This equation applies to all dilution problems.
C1 (initial conc) x V1 (initial volume) = C2 (final conc) x V2 (final volume)
Example : What volume of 6.00 ppm solution must be used to give 4.00 liters of a 0.100 ppm solution?
C1 = 6.00 ppm
V1 = unknown
C2 = 0.100 ppm
V2 = 4 liters = 4000 mls
V1 = (C2 x V2) / C1
= (0.100 X 4000) / 6.00
= 400 / 6.00 = 66.7 mls.
This means that 66.7 mls of the 6.00ppm solution diluted to a final volume of 4 liters will give a concentration of 0.100 ppm.
The Formula below can be used to calculate the V1 component only.
req is the value you want.
req ppm x req vol
-------------------------- = no of mls for req vol
stock
e.g. Make up 50 mls vol of 25 ppm from 100 ppm
25 x 50 / 100 = 12.5 mls. i.e. 12.5 mls of 100 ppm in 50 ml volume will give a 25 ppm solution
Serial dilutions
Making up 10-1 M to 10-5 M solutions from a 1M stock solution.
Pipette 10 ml of the 1M stock into a 100 ml volumetric flask and make up to the mark to give a 10-1 M soln.
Now, pipette 10 ml of this 10-1 M soln. into another 100 ml flask and make up to the mark to give a 10-2 M soln.
Pipette again, 10 ml of this 10-2 M soln. into yet another 100 ml flask and make up to mark to give a 10-3 M soln.
Pipette a 10 ml of this 10-3 M soln. into another 100 ml flask and make up to mark to give a 10-4 M soln.
And from this 10-4 M soln. pipette 10 ml into a 100 ml flask and make up to mark to give a final 10-5 M solution.
Molarity to ppm
Convert molar concentration to grams per liter (Molarity x Atomic mass of solute), then convert to milligrams per liter (ppm) by multiplying by 1000.
e.g. What is the ppm concentration of calcium ion in 0.01M CaCO3?
Molarity(M) x Atomic mass(At Wt) = grams per liter(g/l)
Atomic Mass (Wt.) of Ca = 40
0.01M x 40 =0.40 g/l
0.40g/l x 1000 = 400 mg/l = 400ppm
Ppm to Molarity
Convert ppm to gram based or milligram based concentration.
ppm = 1 mg solute per liter solution or
ppm = 0.001 gram per liter solution
e.g. What is the Molarity of 400ppm Ca ions in an aqueous CaCO3 solution?
Using the 0.001g/l concentration: 400ppm x 0.001g/l = 0.4g/l.
or, Divide 400 mg by 1000 to get g/l = 0.4 g/l
Now divide by the At. Mass of Ca to get Molarity.
0.4g/l divided by 40g/mol =0.01M
Using the mg/l concentration, the 40g Ca must be converted to milligrams by multiplying by 1000 to give 40,000mg.
Hence Molarity = 400ppm divided by 40,000mg/mol = 0.01M
The FW of an ion species is equal to its concentration in ppm at 10-3M. Fluoride has a FW of 19, hence a 10-3M concentration is equal to 19ppm, 1M is equal to 19,000 ppm and 1ppm is equal to 5.2 x 10-5M.
Go here in Table III for ISE molarity/ppm conversions
Ppm (parts per million) to % (parts per hundred)
Example:
1 ppm = 1/1,000,000 = 0.000001 = 0.0001%
10 ppm = 10/1,000,000 = 0.00001 = 0.001%
100 ppm = 100/1,000,000 = 0.0001 = 0.01%
200 ppn = 200/1,000,000 = 0.0002 = 0.02%
5000 ppm = 5000/1,000,000 = 0.005 = 0.5%
10,000 ppm = 10000/1,000,000 = 0.01 = 1.0%
20,000 ppm = 20000/1,000,000 = 0.02 = 2.0%
(Parts per hundred) % to ppm
Example:
0.01% = 0.0001
0.0001 x 1,000,000 = 100 ppm
Ppm (parts per million) to % (parts per hundred)
Example:
1 ppm = 1/1,000,000 = 0.000001 = 0.0001%
10 ppm = 10/1,000,000 = 0.00001 = 0.001%
100 ppm = 100/1,000,000 = 0.0001 = 0.01%
200 ppn = 200/1,000,000 = 0.0002 = 0.02%
5000 ppm = 5000/1,000,000 = 0.005 = 0.5%
10,000 ppm = 10000/1,000,000 = 0.01 = 1.0%
20,000 ppm = 20000/1,000,000 = 0.02 = 2.0%
(Parts per hundred) % to ppm
Example:
0.01% = 0.0001
0.0001 x 1,000,000 = 100 ppm