Answer to Question #163618 in Chemistry for ciara

Question

 How many molecules are present in 500 milimole of AlCl₃? How many atoms is this.

 

Answer 1

According to the Avogadro's number, one mole of any substance contains 6.022 × 10²³ particles. From here, 500 mmol of AlCl3 contains:

n(AlCl₃) = 6.022 × 10²³ × 500 mmol = 6.022 × 10²³ × 0.5 mol = 3.011 × 10²³ molecules

As one molecule of AlCl₃ consists off four atoms, the number of atoms is 500 mmol of AlCl₃ is:

n(atoms) = 3.011 × 10²³ × 4 = 1.2044 × 10²⁴

Answer: 6.022 × 10²³ molecules; 1.2044 × 10²⁴ atoms