Understanding Normality (N)
Normality is a measure of concentration that expresses the number of gram equivalents of a solute per liter of solution. For NaOH, one gram equivalent is equal to its molar mass (40 g/mol).
Calculations
1. Molarity (M): Since 1 N NaOH solution is equivalent to 1 M NaOH solution, a 0.1 N NaOH solution is also 0.1 M.
2. Mass of NaOH:
* 0.1 M NaOH means there are 0.1 moles of NaOH per liter of solution.
* Mass of NaOH = (0.1 moles/L) * (40 g/mol) = 4 g/L
3. Percentage Concentration (w/v):
* Percentage concentration (w/v) is the mass of solute (in grams) per 100 mL of solution.
* Percentage concentration (w/v) = (4 g/L) * (100 mL/L) / 100 mL = 0.4%
Therefore, a 0.1 N sodium hydroxide solution has a percentage concentration of 0.4% (w/v).
