Question

Sodium hydroxide, NaOH, is a strong base that is used in industrial synthesis and processes such as making paper. What is the mass of 2.40 ×1022 molecules of NaOH (Molar mass = 40.0 g/mol)?

Answer 1

Molar mass NaOH = 40.0 g/mol

40.0 g ------------ 6.02x10²³ molecules
?? g -------------- 2.40x10²² molecules

2.40x10²² x ( 40.0 ) / 6.02x10²³ =

9.6x10²³ / 6.02x10²³ => 1.594 g

hope this helps!

Answer 2

Answer:

                  Mass of NaOH =  1.594 g

Solution:

Data Given:

                 Number of Molecules  =  2.40 × 10²²

                 M.Mass of NaOH  =  40.0 g.mol⁻¹

                 Mass of NaOH  =  ?

Step 1: Calculate Moles of NaOH;

  Moles  =  Number of Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹

Putting value,

  Moles  =   2.40 × 10²² Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹

                   Moles  =  0.04 mol

Step 2: Calculate Mass of NaOH;

                   Moles  =  Mass ÷ M.Mass

Solving for Mass,

                   Mass  =  Moles × M.Mass

Putting values,

                   Mass  =  0.04 mol × 40.0 g.mol⁻¹

                   Mass  =  1.594 g