Summary of Facts and Concepts

Therefore, TiCl4 is the limiting reagent because it produces a smaller amount of Ti. The mass of Ti formed is 

Check Should the percent yield be less than 100 percent  

Practice Exercise Industrially, vanadium metal, which is used in steel alloys, can be obtained by reacting vanadium(V) oxide with calcium at high temperatures  

Atomic masses are measured in atomic mass units (amu), a relative unit based on a value of exactly 12 for the C-12 isotope. The atomic mass given for the atoms of a particular element is the average of the naturally occurring isotope distribution of that element. The molecular mass of a molecule is the sum of the atomic masses of the atoms in the molecule. Both atomic mass and molecular mass can be accurately determined with a mass spectrometer. A mole is Avogadro s number (6.022 X 10 ) of atoms, molecules, or other particles. The molar mass (in grams) of an element or a compound is numerically equal to its mass in atomic mass units (amu) and contains Avogadro s number of atoms (in the case of elements). 

Chemical changes, called chemical reactions, are represented by chemical equations. Substances that undergo change—the reactants—are written on the left and the substances formed—the products—appear to the right of the arrow. Chemical equations must be balanced, in 

From the net ionic equation we see that 5 mol Fe — 1 mol MnO. Therefore, the number of moles of FeS04 oxidized is 

The concentration of the FeS04 solution in moles of FeS04 per liter of solution is 

Practice Exercise How many milliliters of a 0.206 M HI solution are needed to reduce 22.5 mL of a 0.374 M KMn04 solution according to the following equation  

The Chemistry in Action essay on p. 158 describes an industrial process that involves the types of reactions discussed in this chapter. 

Aqueous solutions are electrically conducting if the solutes are electrolytes. If the solutes are nonelectrolytes, the solutions do not conduct electricity. 

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