Home Early recorded sounds & wax cylinders Cylinder music shop An Edison commemorative 2nd page Note to early recordings collectors Cylinder of the month Links to related topics What's new Tinfoil resource center Cylinders of the month archive CJ's comics Copyright (C) (P) 1996-2015 Glenn Sage, Portland, Oregon.
1) That looks right. 2) Step 1: Moles=Mass/Mr, so it's 144/72= 2mol. Step 2: Stoichiometry means the ratio of oxygen to pentane is 1:8 so moles of oxygen is moles of pentane times 8. 2*8=16mol of oxygen. Step 3: 16= 9.6*10^24. 3) The ratio of oxygen to carbon in CO2 is 1:2. so it's 192/3 = 64.
1 Empirical formula is a comparison of the number of moles of a compound so you need your values in moles. 2  Using the oxygen example again, there are 16.0 grams per mole of oxygen so 40 grams of oxygen would be 40/16 = 2.5 moles of oxygen.hen you have the molar mass you can find the ratio of the actual mass of the compound to the empirical mass. If the ratio is one (as with water, H 2 O), then the empirical formula and molecular formula are the same.