The molar mass of H2O is 18.02 g/mol. How many moles of H20 are present in 2.15 x 10^24 molecules?

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.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

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