A normal solution is defined as the number of equivalents per liter of solution.

Normality is used to account for different degrees of reactivity of chemicals. One gram

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.

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

4-5

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