Question

there are 1.806x10^25 molecules of water (H20). how many moles of water does the sample contain?
a: 30.0 moles
b: 90.0 moles
c: 1.08 x 10^48 moles
d: 6.02 x 10^24 moles

Answer 1

\[1 mol= 6.02x10^{23}atomss\]
There are 3 atoms in one molecule,
\[1.806molecules \times\frac{3atoms}{1molecule}=5.418 \times10^{25}atoms\]
\[5.418 \times10^{25}atoms \times\frac{1mole}{6.02 \times 10^{23}atoms}=90moles\]