The molar mass of sodium hydroxide (NaOH) can be calculated by adding up the atomic masses of its constituent elements.

The atomic masses of sodium (Na), oxygen (O), and hydrogen (H) are as follows:

Sodium (Na) = 22.99 g/mol

Oxygen (O) = 16.00 g/mol

Hydrogen (H) = 1.01 g/mol

To calculate the molar mass of NaOH, we sum the atomic masses:

Molar mass of NaOH = Atomic mass of Na + Atomic mass of O + Atomic mass of H

= 22.99 g/mol + 16.00 g/mol + 1.01 g/mol

= 40 g/mol