I believe it is C, but I can't guarantee it.
(7.3 x 10^29 atoms) / (24 atoms/molecule) / (6.022 x 10^23 molecules/mol) =
5.1 x 10^4 mol C6H12O6
The third question requires you to solve for the weight of sodium (Na) and weight of Chloride (Cl) from the calculated moles of each element Na, and Cl.
So, you need to multiply the calculated moles of Na with its molar mass (23 g/ mol) to get the answer for Na. And multiply the calculated moles of Cl with its molar mass (35.45 g/mol) to get the answer for Cl.
Following the Law of Conservation of Mass, you simply add the mass of both substances. Thus, 160 grams + 40 grams = 200 grams. So, even if initially, they are in liquid and solid form, they would still have the same mass even if they change phases, owing to that they are in a closed space.
