Express the desired volume in liters.
1L
400 mL X --------= 0.400 L
1000 mL
Multiply the normal concentration times the gram equivalent weight times the volume
expressed in liters to determine the amount of solute needed to prepare the solution.
10 Eq
40.0 g
-------- X -------- X 0.400 L = 160 g
L
Eq
c. Example. What is the Eq/L concentration of an AlPO4 solution that was
prepared by adding 120.0 grams of AlPO4 to a 250 mL flask and adjusting the volume to
the mark?
Solution. Read the problem carefully and determine the desired quantity.
Eq/L concentration.
Determine the GEW of the compound.
AlPO4
Al
27.0 X 1 = 27.0
P
31.0 X 1 = 31.0
O
16.0 X 4 = + 64.0
122.0 g/mol
122.0 g
mol
--------X -------- = 40.67 g/Eq
mol
3 Eq
Express the grams of solute as equivalents using the appropriate conversion
factor.
Eq
120.0 g X --------= 2.951 Eq
40.67 g
MD0837
4-6