Answer:
3.57moles
Explanation:
The number of moles in a compound can be got from the number of molecules it contains.
Since;
number of moles (n) = number of molecules (nA) ÷ Avagadro's number
Avagadro's number = 6.02 × 10^23 molecules
H20 contains 2.15 x 10^24 molecules, according to this question. Therefore,
n = 2.15 x 10^24 ÷ 6.02 × 10^23
n = 0.357 × 10^(24-23)
n = 0.357 × 10^1
n = 3.57moles
Hence, 3.57moles are present in in 2.15 x 10^24 molecules of H2O.
