Bases

NaOH à Na⁺  + OH^-

The blue color indicates that the paper is in an acid medium.

Bases are compounds capable of dissociating in aqueous media releasing ions, of which a single anion is OH-.

* Form electrolytic solutions (conduct electricity).

Ex: NaOH, KOH, NH4 OH

* React with acids by neutralizing reactions and generate salt and water as products.

Ex: H2SO4 + 2NaOH à Na2 SO4 + 2H2O

* Act as acid-base indicators.

Bases are also important for pH reading, solutions with pH higher than 7 are basic. There are several acid-base indicators to identify if the compound is basic, the most commonly used is litmus, but there are others that can also be used. As for force, the bases are determined from their degree of dissociation, for strong bases (value greater than 5%), for weak (value equal to or less than 5%).

LENZI, Ervim, Química Geral Experimental, 2.ed. Rio de Janeiro: F. Bastos, 2012CHRISTOFF, Paulo, Química Geral, Curitiba: Intersaberes, 2015

               

Solutions

Cs: 36g of NaCl in 100ml of H2o the  20°c

Unsaturated

100ml of de H2o with  20g of NaCl

Saturated

100ml of de H2o with  36g of NaCl

Supersaturated

à

 100ml of H20 with 37g of NaCl, is heated to dissolves the  bottom body 

Solutions studied in chemistry are homogeneous, formed by a product and solvent. The solute dissolves the solvent is in largest amount and will act dissolving the solution. The solution can be liquid, solid or gas. Another way to sort the solutions in about this aspect, we have three types of solutions:

Unsaturated: when the amount of solute is less  than it can be dissolved.

Saturated: when the amount of solute is equal to that which can be dissolved without having a bottom body.

Supersaturated: when the amount of solute is greater than it can be dissolved, bt without a bottom body, as the bottom body dissolved after the solution is heated.

referencia :LENZI, Ervim, Química Geral Experimental, 2.ed. Rio de Janeiro: F. Bastos, 2012 CHRISTOFF, Paulo, Química Geral, Curitiba: Intersaberes, 2015

Acids

HCL à H⁺ + Cl^-

According to Arrhenius acids are substances which ionize in aqueous solution, releasing kation H+. There are two types of acids: Oxyacids (they have in their composition the element oxygen) and Hydracids (they do not have in their composition the element oxygen). Acids are also important for pH reading, solutions with pH less than 7 are acidic. pH is related to the activity of the ion H+ in solution. 

^{Ex: H2CO3, H2¬SO4, HI, HF, HCN.}

^reference:LENZI, Ervim, Química Geral Experimental, 2.ed. Rio de Janeiro: F. Bastos ,2012.