
6. The sulfate ion concentration from the unknown is calculated as follows:
V
t
M
t
M
SO
4
-2
= ⎯⎯⎯⎯⎯
V
SO
4
-2
where:
M
SO
4
-2
= concentration of sulfate ion in the unknown (moles/liter)
V
t
= volume of lead added at endpoint
M
t
= lead concentration (moles/liter)
V
SO
4
-2
= volume of unknown sample (50 ml)