How many grams of carbon atoms are present in a sample of C3H8 if there are 4.70 moles of hydrogen atoms in the sample

21.12 grams

Explanation:

Using the given number of hydrogen moles, we calculate the number of carbon atoms, keeping in mind that there are 3 carbon moles per hydrogen mol:

4.70 mol H * = 1.76 mol C

Finally we convert 1.76 moles of carbon into grams, using its molar mass:

1.76 mol * 12 g/mol = 21.12 g