Section II. NORMAL SOLUTIONS
4-5.
DEFINITION
A normal solution is defined as the number of equivalents per liter of solution.
equivalent weight of a substance will react exactly with one gram equivalent weight of
another substance. A one normal solution contains one GEW of solute in one liter of
total solution. Use the following information in solving normality problems.
4-6. SOLVING NORMALITY PROBLEMS
a. Method. Based on the definition given above, it follows that:
(1)
Normality (Eq/L) = number of equivalents per liter of solution
(2)
GEW = grams per equivalent
(3)
Liter = total volume of solution
b. Example. How much NaOH is needed to prepare 400 mL of a 10.0 Eq/L
NaOH solution?
Solution. Read the problem carefully and determine the desired quantity.
Grams of NaOH.
Regardless of the type, most normality problems require the gram equivalent weight, so
calculating the gram equivalent weight is a good starting point.
NaOH
Na
23.0
O
16.0
H
+ 1.0
40.0 g/mol
40.0 g
mol
------X -------- = 40.0 g/Eq
mol
1 Eq
MD0837
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