Here's how to calculate the number of molecules in 2.1 mol of sulfuric acid (H₂SO₄):

1. Avogadro's Number:

* Avogadro's number states that there are 6.022 x 10²³ particles (atoms, molecules, etc.) in one mole of a substance.

2. Calculation:

* To find the number of molecules in 2.1 mol of H₂SO₄, multiply the moles by Avogadro's number:

(2.1 mol H₂SO₄) * (6.022 x 10²³ molecules/mol) = 1.26 x 10²⁴ molecules of H₂SO₄

Therefore, there are approximately 1.26 x 10²⁴ molecules of sulfuric acid in 2.1 moles.