Question

How many moles are present in 1.25x1023 molecules of salt (NaCl)?

Answer 1

0.21 mole of NaCl

Step-by-step explanation:

From the question,

using Avogadro's Constant,

1 mole of every compound contains 6.02×10²³ molecules of that compound.

I.e

1 mole of NaCl ⇒ 6.02×10²³ molecules of NaCl

x moles of NaCl ⇒ 1.25××10²³ molecules of NaCl

Solving for x,

x moles of NaCl = (1 mole of NaCl)×(1.25×10²³ molecules of NaCl)/(6.02×10²³ molecules of NaCl)

x moles of NaCl = (1×1.25×10²³)/6.02×10²³

x = 0.208 mole of NaCl

x ≈ 0.21 mole of NaCl