How many moles of atoms
7.98x 10^24 C2H2

25.8 grams of Co

Number of moles of C₂H₂ = 13.3 mol

Number of moles of Co = 0.92 mol

Explanation:

Given data:

Number of molecules of C₂H₂ = 7.98 ×10²⁴

Number of moles of C₂H₂ = ?

Mass of Co = 25.8 g

Number of moles of Co = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For C₂H₂:

1 mol = 6.022 × 10²³ molecules

7.98 ×10²⁴ molecules × 1 mol / 6.022 × 10²³ molecules

1.33×10¹ mol

13.3 mol

For Co:

Number of moles = mass/ molar mass

Number of moles = 25.8 g/ 28 g/mol

Number of moles = 0.92 mol