Question #b8d89

1 Answer
Dec 21, 2017

Answer:

From the formula, there are #3# #"C"# atoms for every #8# #"H"# atoms. So...

Explanation:

#5.60 * 10^24"H atoms" * "3 C atoms" / "8 H atoms" = 2.1* 10^24# #"C atoms"#

Now, to get to the mass of the sample, you must calculate the number of moles of #"C"_3"H"_8# in the sample, and then use the molar mass of #"C"_3"H"_8# to calculate the mass in grams:

#5.60* 10^24 "H atoms" xx ("1 molecule C"_3"H"_8) / "8 H atoms" xx ("1 mole C"_3"H"_8) / (6.02xx10^23 "molecules") = "1.162 moles C"_3"H"_8#

#"Molar mass" = 3 xx "12 g/mol" + 8 xx "1 g/mol" = "44 g/mol"#

So

#"Total mass" = "1.162 moles C"_3"H"_8 xx "44 g/mol" = "51.1 g C"_3"H"_8#