Question

How many atoms of each element (Carbon, Hydrogen and Oxygen) are in a sample of 1.202 grams of Sucrose (C12H22O11)?

There are 0.042 moles Carbon, 0.077 moles Hydrogen and 0.386 moles Oxygen in this sample.

Answer 1

If they already give you the amounts of moles of each element, the 1.202 g shouldn't be important. Multiply each mole amount by Avagadro's number (6.02 x 10^23 atoms/mole) to get each element's amount in atoms.

So:

Carbon: 2.5x10^22 atoms

Hydrogen: 4.6x10^22 atoms

Oxygen: 2.3x10^23 atoms

Hope this helps!