Question

What is the mass of 7.675 x 1023 atoms C? Answer in units of g.

Answer 1

Answer: 15.3 grams C

Explanation:  1 mole is 6.02x10^23 atoms.  We can find the moles of C in 7.675 x 10^23 atoms of C by dividing:

(7.675 x 10^23 atoms C)/(6.02x10^23 atoms C/mole) = 1.275 moles C

The molar mass of carbon is 12g/mole.  So the mass of 7.675 x 10^23 atoms is (1.275 moles C)*(12 g/mole C) = 15.3 grams.