Answer:
160.9 mol ≅ 161.0 mol.
Step-by-step explanation:
- It is known that every 1.0 mole of compound or element contains Avogadro's number (6.022 x 10²³) of molecules or atoms (formula units).
Using cross multiplication:
1.0 mole of Fe(NO₃)₃ contains → 6.022 x 10²³ formula units.
??? mole of Fe(NO₃)₃ contains → 9.69 x 10²⁵ formula units.
∴ The no. of moles of He contains (9.69 x 10²⁵ formula units) = (1.0 mol)(9.69 x 10²⁵ formula units.)/(6.022 x 10²³ formula units) = 160.9 mol ≅ 161.0 mol.