What is the mass of 2.30 * 1022 molecules of NaOH (Molar mass = 40.0 g/mol) ?

1.52 g NaOH

Explanation:

The molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by the amount of substance.

Molar mass of NaOH is 40.0 g/mol

40.0 g/mol contains 6.022 * 10²³ molecules

∴ 2.30 * 10²² molecules will contain (2.30 * 10²²) * (40.0) / 6.022 * 10²³

= 1.52 g NaOH