Unit Conversions Stoichiometry

1
Unit Conversions (Stoichiometry)

• How many g of solid Na2SO4 must be used to
  produce 500.00 mL of 0.125 M Na solution?
• How many parts per thousand (ppt) by mass of Na
  is in solution (density of solution is 0.977
  g/mL)?

2
Fractional Composition
The mass of what you are interested in.
Multiply by the number corresponding to the units
that you wish to report (in this case parts per
thousand)
The total mass that it is contained in.

• Percent () 100
• Parts per thousand (ppt) 1000
• Parts per million (ppm) 1x106
• Parts per billion (ppb) 1x109

3
Dilutions

• How many mL of a 0.125 M solution of Na is
  needed to make 250 mL of a 0.0150 M Na solution?
• Use M1V1 M2V2
• M1 0.125 M
• M2 0.0150 M
• V2 250 mL
• V1 ?

4
Reading for Next Time

• Chapters 12 all
• Chapter 3, pgs 39-44

Problems to Work on

• Chap 1 (1,7,19,20,35)