a substance that changes color at a certain pH range.

HIn + H2O ↔ H3O + In-

Acid color base color

When just a small amount of indicator is added to a solution, the indicator does not affect the pH of the solution

These are common indicators that can be seen around us. Many plants contain chemicals from the naturally colored:

Red cabbage Lemon to be an acid-base indicator.Anthocyanin- is the pigment that causes the change of color in some natural indicators.

Identify its color:

Methyl orange at high pHMethyl red at low pHPhenolphthalein at high pHBromothymol blue at low pH

they are used in soil testing kits to establish the approximate pH of soils. Soils are usually acidic in regions of high rainfall and heavy vegetation, and they are alkaline in more arid regions.

In swimming pools, chlorinating agents are most effective at a pH of about 7.4. At this pH the growth of algae is avoided , and the corrosion of pool plumbing is minimized. Phenol red is a common indicator used in testing swimming pool water.

is a chemical reaction between an acid and a base that destroys the characteristic properties of both and produces salt and water.

H+ (aq) + Cl- (aq) + Na+

(aq) + OH- (aq)

acid base

→ Na+ (aq) + Cl- (aq) + H2O

salt water

Excess gastric in the stomach (acid indigestion) is typically neutralized by the ingestion of sodium bicarbonate (NaHCO3) or neutralizing agent such as an antacid.

due to behavior of cation

and anion.

1. A salt of a strong acid and a strong base.

Example:

HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)

Strong acid strong base neutral

Example:

HCl (aq) + NH4OH → NH4Cl (aq) + H2O (l)

Strong acid weak base slightly acidic

Example:

H2CO3 (aq) + 2NaOH (aq) → Na2CO3 + 2H2O

Weak acid strong base slightly basic

Example:

HCN (aq) + NH4OH → NH4CN (aq) + H2OWeak acid weak base

but it depends on acid dissociation and base dissociation constant.

if Kb > Ka, the solution will be basic, whereas if Kb < Ka, the solution will be acidic.

For example, if the acid HClO has a Ka of 3.4 x 10-8 and the base NH3 has a Kb = 1.6 x 10-5, then the aqueous solution of HClO and NH3 will be basic because the Ka of HClO is less than the Kb of NH3.

Find the parent Identify the conjugate acid and base

Example:NaClNH4Cl

NH4CN

2NaOH + H2SO4→ H2SO4 + 2NH4OH →

Identify if it is acidic, basic or neutral using the two steps:

Na2CO3

NaCl Na2S

Titration- the process of reacting a solution of unknown concentration with one of known concentration.

Volumetric analysis- the procedure of measuring the volumes of solutions

Titrant - a substance added slowly to a measured volume of an acid or a base solution of unknown concentration

Neutralization point or equivalence point- the point at which the titrant is enough to fully neutralize the acid or base.

Aquarium Water Testing Titration is used to test the underwater environment in fresh water and marine aquariums. Properties such as water pH and concentration of ammonia, nitrates and nitrites are measured and then corrected to ensure the survival of marine life being kept in the aquarium.