Acids and Bases

An acid is any hydrogen-containing substance that is capable of donating a proton (hydrogen ion) to another substance. When an acids dissolves in water it donates it's hydrogen ions to the water molecules .

HCl  (g)+ H2O (l)  $\rightarrow$  H30+ (aq)  + Cl- (aq)

produce one mole of H+ ions per mole of acid. For example:
HCl (aq) $\rightarrow$  H+ (aq) + Cl- (aq)

1 mole       1 mole

produce two moles of H= ions per mole of acid. for example,
H2SO4 (aq)  $\rightarrow$  2H+ (aq) + SO4  $2-$  (aq)

Produce three moles of H+ ions per mole of acid. For example,
H3Po4(aq)  $\rightarrow$  3H+ (aq) + PO4   3- (aq)

Strong acids and weak acids

dissolves completely in water to produce the maximum number of H+ ions. For example,
HCl (aq)  $\rightarrow$  H+(aq)   + Cl- (aq)

dissolves partially in water, the contain low concentration of H+ ions. For example,
CH3COOH (aq)  $\rightarrow$  CH3COO- (aq) + H+ (aq)

A base can be defined as a substance that will react with n acid to from salt and water only. A proton (H+ ion) acceptor.

An Alkali is a base which dissolves in , or react with, water to form a solution which contains OH- ions forming what is called an alkaline solution.

Similarly to acids, a strong base completely dissolves in water, their solutions contain a high concentration of OH- ions. For example,
NaOH(aq)  $\rightarrow$  Na+ (aq) + OH-(aq)

An oxide that combines with water to give an acid is termed as an acidic oxide. Acidic oxides are the oxides of non-metals (Groups 14-17) and these acid anhydrides form acids with water. For example,

SO2+H2O→H2SO3 (Sulfurous acid)

The oxide that gives a base in water is known as a basic oxide. (when an oxide reacts with water to produce a base. Group 1 and 2 elements form basic oxides. For example,
K2O (s) + H2O (l)  $\rightarrow$  2KOH (aq)

A slat is a compound that is formed after the reaction of a acid and a base. A salt consists of the positive ion (cation) of a base and the negative ion (anion) of an acid.

Acid salts are formed when only some of the H+ ions are replaced. They contain some H+ ions from the original acid. For example,
NaOH(aq) + H2SO4 (aq)  $\rightarrow$  NaHSO4 (aq) + H2O (l)

A normal salt is formed when all the H+ ions are replaced. For example,
2NaOH (aq) + H2SO4(aq)  $\rightarrow$  Na2SO4(aq)  + 2H2O (l)