Solution:
Step 1: Calculate the molar mass of NaOH.
molar mass = (22.99 g/mol × 1) + (16.00 g/mol × 1) + (1.008 g/mol × 1)
molar mass = 39.998 g/mol
Step 2: Calculate the number of formula units of NaOH.
[tex]\text{number of NaOH formula units = 20 g NaOH} × \frac{\text{1 mol NaOH}}{\text{39.998 g NaOH}} × \frac{\text{6.022 × 10²³ NaOH formula units}}{\text{1 mol NaOH}}[/tex]
[tex]\boxed{\text{number of NaOH formula units = 3.01 × 10²³ formula units}}[/tex]
