What is the mass of 5.119 102 molecules of copper sulfate
(CuSO4)?

Mass = 135.66 ×10⁻²¹ g

Explanation:

Given data:

Number of molecules of CuSO₄= 5.119×10²

Mass of CuSO₄= ?

Solution:

The given problem will solve by using Avogadro number.

1 mole contain 6.022×10²³ molecules

5.119×10² molecules ×1 mol / 6.022×10²³ molecules

0.85×10⁻²¹ mol

Mass in grams:

Mass = number of moles × molar mass

Mass = 0.85×10⁻²¹ mol × 159.6 g/mol

Mass = 135.66 ×10⁻²¹ g

it means there are 3 atoms of oxygen