Question

A sample of toluene, C7H8 has a mass of 74.5 g.
a) how many molecules does the sample contain?
b) How many carbon atoms does it contain? How many hydrogen atoms does it contain?

My work
For b would it be 7 carbon atoms and 8 hydrogen atoms

Answer 1

If it weighs any number of grams it has millions of atoms even if it is URANIUM!!!!!

6.02 * 10^23 molecules/mol
Avagadro's constant

7 C = 84 g/mol
8 H = 8 g/mol
so 92 g/mol

(74.5/92) * 6*10^23 = 4.86 *10^23 MOLECULES

7 times that many C atoms
8 imes that many H atoms

Answer 2

So would i multiply 4.86 x 10^23 by 7 to get the number of carbon atoms
And multiply by 8 to get the number of hydrogen atoms