Question

"How many Na+ atoms are in 100 mL of 2 M sodium sulfate, Na₂SO₄

a.) 1.2 x 10²³ atoms
b.) 2.4 x 10²³ atoms
c.) 1.4 x 10²¹1 atoms
d.) 8.9 x 10²⁴ atoms

Answer 1

There are 1.2 x 10²³ Na+ atoms in 100 mL of 2 M sodium sulfate.

Step-by-step explanation:

To find the number of Na+ atoms in 100 mL of 2 M sodium sulfate (Na₂SO₄), we need to first calculate the number of moles of Na+ ions in the solution.

1 molecule of Na₂SO₄ contains 2 Na+ ions, so in 2 moles of Na₂SO₄, there are 4 moles of Na+ ions. Since the solution is 2 M, there are 2 moles of Na₂SO₄ in 1 L (1000 mL) of solution.

Therefore, the number of moles of Na+ ions in 100 mL of 2 M Na₂SO₄ is 2/1000 x 100 = 0.2 moles. Since 1 mole of any substance contains 6.02 x 10²³ particles (Avogadro's number), the number of Na+ atoms in 0.2 moles is 0.2 x 6.02 x 10²³ = 1.2 x 10²³ atoms.