How much water, in grams, can be made from1.11 × 1024 hydrogen molecules? answer in units of g., i don't understand this at all. i need : /

A famous Italian scientist named Amedeo Avogadro (not avocado) realized that certain elements were naturally heavier than others, so 1 gram of gold, for instance, had far fewer atoms than 1 gram of lithium. He created a unit of measure, called a mole, which we now know is equal to  particles of a substance.

It is defined such that 12 grams of carbon-12 is equal to 1 mole, but we don't actually need to know that. We use the atomic mass units on the periodic table of the elements to get a molar mass in moles per gram.

For instance, nitrogen has an atomic mass of 14.01 amu. This is equivalent to 14.01 grams per mole.

With this information, let's find how many moles are in  hydrogen molecules.

We use Avogadro's number, which says that 

.

So, making this our conversion factor, we have 


From the periodic table of the elements, we have
.

But, since we have diatomic (molecular) hydrogen, this is actually . So, we double our number.



Now, we use this molar mass as our conversion factor to get from moles to grams.