Nota Aula 2 13_06_17 Engenharia Econômica

Reactions in Aqueous Solutions Aqueous solutions contain water as the solvent. Water is a polar molecule, which means it has a positive and negative side. When an ionic compound dissolves in water, the ions separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions. This is why ionic compounds are good conductors of electricity when dissolved in water. Types of Reactions in Aqueous Solutions: 1. Precipitation reactions: These occur when two aqueous solutions combine to form an insoluble solid called a precipitate. A precipitate is a solid product that separates from a solution. 2. Acid-base reactions: These occur when an acid and a base react to form water and a salt. The hydrogen ion from the acid combines with the hydroxide ion from the base to form water. 3. Redox reactions: These involve the transfer of electrons between two species. One species undergoes oxidation (loses electrons), while the other undergoes reduction (gains Table 1. Solubility Rules Soluble Compounds Exceptions 1. All compounds of NH4+ - 2. All compounds of Alkali metal (Li+, Na+, K+, etc.) - 3. All nitrates (NO3-) - 4. Most chlorides, bromides, and iodides Except: Ag+, Pb2+, Hg2+ 5. Most sulfates (SO42-) Except: Ba2+, Sr2+, Pb2+, Ca2+, Ag+ Insoluble Compounds 6. Most hydroxides Except: Na+, K+, Ba2+, Sr2+, Ca2+ 7. Most carbonates (CO32-) Except: NH4+, Alkali metals 8. Most phosphates (PO43-) Except: NH4+, Alkali metals 9. Most sulfides (S2-) Except: NH4+, Alkali metals, Alkaline earth metals PB T CT Table c Reacting masses and volumes Volume of gas at room and pressure In cm 24 cm oxygen elements in compounds imple 1 (f1 tincture of iodine) solutions; dicates of iron with ction = o