Household Sugar, Sucrose, has the molecular formula C12H22O11. What is the % Carbon in sucrose by mass?
It’s been ages since chemistry (I won’t tell you how many ages) but I still remember how to do this one. I’ll point you in the right direction, and then I think you’ll be able to figure it out. First of all, note that they are asking about “mass”. You can’t figure this one out solely from the information in the question. But you know about the periodic table of the elements, of course, and the difference between atomic number, which has to do with protons, and atomic weight, which has to do with protons plus neutrons (electrons weighing almost nothing). And you also know about isotopes of carbon, so that the atomic mass of carbon isn’t exactly 12 as it is for C12 (6 protons and 6 neutrons) because there are also varieties of carbon out there with different numbers of neturons, 7, or 8 or more, and since the mix of different isotopes of carbon in the wild isn’t exactly one to one, the actual atomic mass of carbon is a fractional value a little greater than 12 (go look it up in the perio
