Solubility NaCl + NaOH mixed solutions

How do we recognize acid-base reactions One of the most difficult tasks for someone inexperienced in chemistry is to predict which reaction might occur when two solutions are mixed. With precipitation reactions we found that the best way to deal with this problem is to focus on the species actually present in the mixed solution. This also applies to acid-base reactions. For example, when an aqueous solution of hydrogen chloride (HCl) is mixed with an aqueous solution of sodium hydroxide (NaOH), the combined solution contains the ions H, Cl, Na, and OH, since HCl is a strong acid and NaOH is a strong base. How can we predict what reaction occurs, if any First, will NaCl precipitate From Table 4.1 we know that NaCl is soluble in water and thus will not precipitate. The Na and Cl ions are spectator ions. On the other hand, because water is a nonelectrolyte, large quantities of H and OH ions cannot coexist in solution. They will react to form H2O molecules ... 

Aqueous amylose solution (1%) was prepared by dissolving amylose powder in hot water (80°C). A 1% salt free aqueous water-soluble chitosan (WSC) was obtained by the dialysis of a WSC solution that included NaCl produced by the neutralization of a dilute hydrochloric acid solution of WSC with NaOH. Each film having a thickness of 40-50 om was prepared by casting the amylose, WSC, or their mixed solutions at 60°C. A film of fully deacetylated chitosan was obtained by casting a 0.1 M aqueous AcOH solution of fully deacetylated chitosan (1%) on a Kapton (polyimide) film. The resulting acidic chitosan film was neutralized with 1M aqueous NaOH followed by washing with water and then dried. 

In a later study Felmy et al. [1999FEL/RAI] extended their model to alkaline NazCOz-NaCl solutions. The experimental solubility data determined with ThOz(am, hyd) in 2.33 and 4.67 m NaCl containing 0.1-2.3 M NazCOs and 0.1 M NaOH were fitted with mixing parameters of 0(Th(CO31 -CF) = 1.8 kg-mol and v /( Th(C03 )j -CF-Na ) = 0.3 kg -moF, indicating that the activity coefficients of Th(C03)j in NazCOs-NaCl solutions differ considerably from those in NazCOs-NaC104 solutions. 

Just one more example before we move on to the next chapter. An aqueous solution of FeClj is yellow. An aqueous solution of NaOH is colorless. If we mix the two solutions together, we get a rusty brown precipitate. We know from rule 1 that NaCl is soluble. Rule 6 tells us that FeCOHJj is insoluble. Therefore, in this reaction Na+ and Cl are spectator ions and the precipitate is Fe(OH)3. This reaction is shown in the following net ionic equation ... 

---