# Question f0b2c

Mar 24, 2017

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#### Explanation:

Avogadro constant is defined as the number of molecules present in one mole of compound.

One mole of water is $18$ grams.

Since $3.0 \cdot {10}^{- 21}$ grams contain $200$ molecules, it follows that $18$ grams should have

18 cancel("grams") xx 200/(3 xx 10^(-21) cancel("grams")) = 12 xx 10^23#

Which shows something is wrong with the question because Avogadro's constant is $6.02 \cdot {10}^{23}$.