Sodium hydroxide, naoh, is a strong base that is used in industrial synthesis and processes such as making paper. what is the mass of 2.60 ×1022 molecules of naoh (molar mass = 40.0 g/mol)?

  The  mass of 2.60 x10^22  molecules of NaOH  is   1.728   grams

calculation
 mass = moles  x molar mass
   molar mass = 40 g/mol

mole   is calculated   using the Avogadro   law
that is  1 mole =   6.02 x10^23 molecules
              ?        =  2.60  x10 ^ 22  molecules

by   cross   multiplication

 (1 mole x  2.60  x10^22) /  6.02 x0^23  =  0.0432  moles

mass   is therefore= 0.0432  mole x  40 g/mol = 1.728 grams