How many moles are there in 1.505 X 1024 molecules of water, H2O?

Question

A) 2.5 moles

B) 2.50 moles

C) 9.03 moles

D) 9.03 x 10⁴⁷ moles

Answer 1

1.505x10²⁴ molecules H2O x 1 mole H2O / 6.02x10²³ molecules = 2.50 moles

ANSWER B (3 sig. figs. based on the value used for Avogadro's number)