Question

Find the number of molecules of 3.01x1023 mole of HCI.

Answer 1

I dare to suggest that 3.01*10²³ is not a number of moles but number of molecules, so the task is reverse - to derive number of moles from number of molecules, check it please (too large amount of moles, usually such quantities represent amount of single particles - atoms, molecules, not moles).

Anyway

N = n*Na(Avogadro constant)

• if n = 3.01*10²³ (my assumption is wrong and your task is right) then

N = 3.01*10^23*6.02*10²³ = 1.812*10⁴⁷ molecules

• if N = 3.01*10²³ (my assumption is correct) then

n = 3.01*10²³ / 6.02*10²³ = 0.5 moles