Asnowflake contains 1.9 1018 molecules of water. how many moles of water does it contain?

3.16× 10^40 moles.

Explanation:

Before we dive Right into the question, let us take one or two facts down. From the question, we know that we are to find the number of moles of water that the snowflake contains.

MEANING OF MOLE: A mole is an SI unit usually represented as 'mol'. A mole can be defined as the mass of substance containing the same number of elementary units as there are atoms in exactly 12grams of carbon-12.

ADDITIONAL INFORMATION:

One mole of any substance contains 6.02214076 × 10^23 of either molecules, ions, electrons or atoms. This value is exactly the value given for Avogrado's constant.

SOLVING THE QUSTION: Therefore, from the above explanations, we can see that;

One mole of any substance= 6.02214076 × 10^23 molecules.

That is;

One mole of snowflake= 6.02214076 × 10^23 molecules.(1).

X moles= 1.9 × 10^18 molecules. (2).

Hence, combination of equation (1) and (2) gives;

1.9×10^18/6.02214076 × 10^23.

= 3.16× 10^40 moles