How many molecules of H2 are present in 7.5 grams of H2? How many H atoms?

The answer is 2.258 x 10^24 molecules are presented in 7.5 grams of H2.

Explanation:

I am going to use the chart that I attached to answer this question.

To convert grams to molecules we need to divide by the molar mass and multiply by 6.02 x 10^23, which is the value of a mole.

In this case the molar mass is 2 because the molar mass of H is 1 and we need to multiply by 2 to get the molar mass of 2 hydrogens.

Molar Mass = 1 x 2 = 2

Then, we need to divide the grams that we have by 2 to covert grams into moles. Finally, to convert moles into molecules we need to multiply the moles by 6.02 x 10^23.

7.5 grams / 2 = 3.75 moles

(3.75 moles)(6.02 x 10^23) = 2.258 x 10^24 molecules

Molecules are equal to atoms, so 2.258 x 10^24 molecules = 2.258 x 10^24 atoms