Question

How many moles of water are in 1.23x10^18 water molecules

Answer 1

Answer:

There are 2.04*10⁻⁶ moles of water in 1.23*10¹⁸ water molecules

Explanation:

Avogadro Number is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of that substance. Its value is 6.023 * 10²³ particles per mole. The Avogadro number applies to any substance.

In this case you know that there are 1.23*10¹⁸ molecules of there. So, knowing Avogadro's number, a rule of three applies as follows: if 6.023*10²³ molecules represent 1 mole of the compound, 1.23*10¹⁸ molecules in how many moles will they be?

$moles=\frac{1.23*10^{18} molecules*1mole}{6.023*10^{23}molecules }$

moles=2.04*10⁻⁶

There are 2.04*10⁻⁶ moles of water in 1.23*10¹⁸ water molecules

Answer 2

By 1.23 x 1024 you mean 10 to the power of 24 molecules? If so all you need to do is divide the number of molecules you have by Avagadros number, 6.022 x 10^23. This will give you the mols of water, or the mols of anything, since there is always 6.022 x 10^23 molecules in 1 mol of substance.

1.23x10^24 atoms/6.022x10^23 atom/mol = 2.04 mol H20