Question

How many molecules are in 0.0021 mol of magnesium oxide?

Answer 1

Solution:

magnesium oxide = MgO

One mole of any substance contains 6.022×10²³ atoms/molecules.

Hence,

Number of MgO molecules = (0.0021 mol MgO)×(6.022×10²³ molecules / 1 mol) = 4.78×10²¹ molecules

Number of MgO molecules = 1.26×10²¹ molecules

Answer: 1.26×10²¹ molecules are in 0.0021 mol of magnesium oxide (MgO).