text: For some reason, there seems to be confusion on this question. My answers, in short are d < a < b < c. Here is my explanation:\n\na) a mole is a mole, which equals to 6.02 x 10^23 molecules (no calculations needed here)\n\nb) 27g H2O * (6.02 x 10^23 molecules/ 18g H2O) = 9.03 x 10^23 --- here you can estimate...pull out a nine, leaving three-halves times 6.02 and tack on the exponential\n\nc) 34g NH3 * (6.02 x 10^23 molecules/ 17g NH3) = 12.04 x 10^23 molecules\n\nd) 22g CO2 (6.02 x 10^23 molecules/ 44g CO2) = 3.01 x 10^23 molecules