The paragraph preceding Example 1.1 in the text mentions that the atomic mass of aluminum is 27.0u = 27.0 x 1.66 x 10-27 kg. Example 1.1 says that 27.0u g of aluminum contains 6.02 x 1023 atoms.
(a) Prove that each one of these two statements implies the other.
(b) What If? What if it’s not aluminum? Let M represent the numerical value of the mass of one atom of any chemical element in atomic mass units. Prove that M grams of the substance contain a particular number of atoms, the same number for all elements. Calculate this number precisely from the value for u quoted in the text. The number of atoms in M grams of an element is called Avogadro’s number NA. The idea can be extended: Avogadro’s number of molecules of a chemical compound has a mass of M grams, where M atomic mass unit is the mass of one molecule.
Avogadro’s number of atoms or molecules is called one mole, symbolized as 1 mol. A periodic table of the elements, as in Appendix C, and the chemical formula for a compound contain enough information to find the molar mass of the compound.
(c) Calculate the mass of one mole of water, H2O.
(d) Find the molar mass of CO2-

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