Sodium hydroxide, NaOH is a strong base that is used in industrial synthesis and process such as making paper.

What is the mass 2.60x10^22 molecules of NaOH (molar mass=40.0g/mol) ?

Express the mass in grans to three significant figures

Avagadros number / constant states that there are 6.022 x 10²³ units making up 1 mol of any substance.

In NaOH - there are 6.022 x 10²³ NaOH molecules in 1 mol of NaOH

Mass of 1 mol of NaOH - 40 g

therefore 6.022 x 10²³ molecules weigh - 40 g

Then 2.60 x 10²² molecules - 40 x 2.60 x 10²² / (6.022 x 10²³)

mass is then - 1.73 g