Understanding of Acid, Base and Salt
Understanding Acids, Bases, Salt, Characteristics, Properties, Indicators, Images and Examples: Acids are chemical compounds that when dissolved in water will produce a solution with a pH less than 7. Bases are chemical compounds that absorb hydronium ions when dissolved in water. Bases have a pH greater than 7. Salt or "Sodium Chloride" (Nacl) is an ionic compound consisting of positive ions (cations) and negative ions (anions)
Understanding of Acid Bases and Salt
Acids and bases have been known since ancient times. The term acid (acid) comes from the Latin acetum which means vinegar. The term base (alkali) comes from Arabic which means ash. Bases are used in making soap. It has also been long known that acids and bases neutralize each other. In nature, acids are found in fruits, for example the citric acid in oranges serves to give a sharp lemonade flavor.
Vinegar contains acetic acid, and tanned acid from tree bark is used to tan the skin. Stronger mineral acids have been made since the Middle Ages, one of which is aqua forti (nitric acid) which is used by researchers to separate gold and silver.
Understanding Acid
Understanding Acid is Acid in chemistry is a chemical compound that if dissolved in water will produce a solution with a pH less than 7. In the modern definition, acid is a substance that can give protons (H + ions) to other substances (called bases) , or can accept a lone pair of electrons from a base.
Basic understanding
Bases are substances that can act with acids, producing compounds called salts. While base is a substance that can neutralize acids. Chemically, acids and bases are opposites. The nature of the base is generally shown from the bitter and slippery taste.
Understanding Salt
In chemistry, salt is an ionic compound consisting of positive ions (cations) and negative ions (anions), so that they will form neutral (without charged) compounds. Salt is formed from the results of an acid and base reaction.
Theories of Acids and Bases According to Arrhenius
In 1884, Svante Arrhenius (1859-1897) a Swedish scientist who won the Nobel Prize for his work in the field of ionization, introduced the thought of compounds that were separated or decomposed into parts of ions in solution. He explained how the strength of acids in aqua (water) solution depends on the concentration of hydrogen ions in them.
According to Arrhenius, acids are substances that in water release H + ions, whereas bases are substances that in water release OH- ions. So the acidic carrier is the H + ion, while the alkaline carrier is the OH- ion. Arrhenius acid is formulated as HxZ, which in water undergoes ionization as follows.
HxZ ⎯⎯ → x H + + Zx–
The amount of H + ions that can be produced by 1 acid molecule is called valence acid, while negative ions that form from acids after releasing H + ions are called acidic residual ions. Some examples of acids can be seen in the table
acid type table
The Arrhenius base is a metal hydroxide, M (OH) x, which in water decomposes as follows.
M (OH) x ⎯⎯ → Mx + + x OH–
The amount of OH ions that can be released by one base molecule is called base valence. Some base examples are given in the table
base type table.jpg Sulfuric acid and magnesium hydroxide in ionizing water as follows.
H2SO4 ⎯⎯ → 2 H + + SO42–
Mg (OH) 2 ⎯⎯ → Mg + + 2 OH–
The water ionization equation can be written as:
H2O (l) ← ⎯⎯⎯⎯ → H + (aq) + OH– (aq)
The price of water constant is:
Price for water
The concentration of H2O ionized into H + and OH– is very small compared to the initial H2O concentration, so the H2O concentration can be considered constant, then the value of K [H2O] is also fixed, which is called the water equilibrium constant or written in Kw.
H2O concentration
At 25 ° C, the Kw obtained from the experiment was 1.0 × 10–14.
This Kw price depends on temperature, but for experiments where the temperature does not deviate too much from 25 ° C, the Kw price can be considered fixed.
Kw prices at various temperatures can be seen in the following table.
Price table K
Strength of acids and bases
Acid Strength
Acid strength is influenced by the number of H + ions produced by acidic compounds in the solution. Based on the many at least H + ions produced, acid solutions can be divided into two types as follows.
Strong Acid
Strong acid is an acid compound which in its solution ionizes entirely into its ions. The strong acid ionization reaction is an end reaction. In general, strong acid ionization is formulated as follows.
HA (aq) ⎯⎯ → H + (aq) + A– (aq)
Strong Acid
Weak Acid
Weak acids are acidic compounds in which the solution is only slightly ionized into ions. The weak acid ionization reaction is an equilibrium reaction. In general, the valence of weak valence one can be formulated as follows.
HA (aq) ← ⎯⎯⎯⎯ → H + (aq) + A– (aq)
The stronger the acid, the more acidic equilibrium reaction will turn to the right, as a result Ka increases. Therefore, the value of Ka is a measure of acid strength, the greater the Ka the stronger the acid. Based on the above equation, because of the weak acid [H +] = [A–], the above equation can be changed to:
Weak Acid Examples of acids
Alkaline Strength
The strength of a base is influenced by the number of OH ions produced by the base compound in the solution.
Based on how much OH ions are produced, base solutions are also divided into two types as follows.
Strong bases
A strong base is a base compound which ionizes entirely into its ions. The strong base ionization reaction is an end reaction.
In general, strong base ionisations are formulated as follows.
M (OH) x (aq) ⎯⎯ → Mx + (aq) + x OH– (aq)
Strong bases
Weak base
Weak bases are base compounds in which the solution is only slightly ionized into ions.
The weak base ionization reaction is also an equilibrium reaction.
In general, weak valence one ionization bases can be formulated as follows.
M (OH) (aq) ← ⎯⎯⎯⎯ → M + (aq) + OH– (aq)