Chapter 1414.1 Molecular Mass, the Mole, and Avogadro’s NumberSlide 3Slide 4Slide 5Slide 6Chapter 14The Ideal Gas Law and Kinetic Theory14.1 Molecular Mass, the Mole, and Avogadro’s NumberTo facilitate comparison of the mass of one atom with another, a mass scaleknow as the atomic mass scale has been established.The unit is called the atomic mass unit (symbol u). The reference element ischosen to be the most abundant isotope of carbon, which is called carbon-12.kg106605.1u 127The atomic mass is given in atomicmass units. For example, a Li atom has a mass of 6.941u.14.1 Molecular Mass, the Mole, and Avogadro’s NumberOne mole of a substance contains as manyparticles as there are atoms in 12 grams ofthe isotope cabron-12.The number of atoms per mole is known asAvogadro’s number, NA.123mol10022.6ANANNn number ofmolesnumber ofatoms14.1 Molecular Mass, the Mole, and Avogadro’s Numbermoleper MassparticleparticlemNmNmnAThe mass per mole (in g/mol) of a substancehas the same numerical value as the atomic or molecular mass of the substance (in atomicmass units).For example Hydrogen has an atomic massof 1.00794 g/mol, while the mass of a single hydrogen atom is 1.00794 u.14.1 Molecular Mass, the Mole, and Avogadro’s NumberExample 1 The Hope Diamond and the Rosser Reeves RubyThe Hope diamond (44.5 carats) is almost pure carbon. The RosserReeves ruby (138 carats) is primarily aluminum oxide (Al2O3). Onecarat is equivalent to a mass of 0.200 g. Determine (a) the number ofcarbon atoms in the Hope diamond and (b) the number of Al2O3 molecules in the ruby.14.1 Molecular Mass, the Mole, and Avogadro’s Number      mol 741.0molg011.12carat 1g 200.0carats 5.44moleper Massmn(a)(b)         mol 271.0molg96.101carat 1g 200.0carats 138moleper Mass99.15398.262mn  atoms1046.4mol10022.6mol 741.023123AnNN  atoms1063.1mol10022.6mol