Calculate the number of carbon atoms in 25.0 grams of isopropyl alcohol (c3h8o)

First, let's determine the number of moles of carbon atoms by using molar mass. Then, using Avogadro's number, we can find the number of C atoms:

*1 mole of C3H8O = (12.0x3) + (1.0x8) + (16.0x1) = 60.0g/mol

25.0 grams C3H8O x (1 mole C3H8O/60.0 grams) = 0.417 mol

0.417mol C3H8O has (3 x 0.417 moles) C atoms = 1.251 moles C atoms

1.251 moles C atoms x (6.022x10^23 atoms/mol) = 9.42x10^23 C atoms.

The answer is in 3 significant figures, as that's what we have in the given, and we matched it with our rounding of the atomic masses from the periodic table.

You can do this all in one equation written left to right, just exclude the intermediate answers. Just easier to show it this way on the computer screen.