Chemistry Acid and Bases

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ACID AND BASES Prepared by: Alvin Sia SMSM Definition of an acid
An acid is a chemical substance that ionize in water and produce hydrogen ion, H⁺ Uses of acids, bases and alkalis
Acid| Uses|
Nitric acid| Make fertilizer|
Benzoic acid| Preserve food|
Methanoic acid | Coagulate latex|
Sulphuric acid | Make paints|

Bases| Uses|
Aluminium hydroxide| Make gastric pill|
Sodium hydroxide| Make soap, paper,detergent|
Ammonia| Remove grease|

Uses of acids, bases and alkalis
Acid| Uses|
Nitric acid| Make fertilizer|
Benzoic acid| Preserve food|
Methanoic acid | Coagulate latex|
Sulphuric acid | Make paints|

Bases| Uses|
Aluminium hydroxide| Make gastric pill|
Sodium hydroxide| Make soap, paper,detergent|
Ammonia| Remove grease|

Bases and alkalis
A base is defined as a chemical substance which can react with an acid to form a salt and water. HCl + NaOH NaCl + H₂O
Thus, all oxide and hydroxide metals and ammonia are bases.
Most of the bases are insoluble in water .

Bases with are soluble in water are called alkalis.

An alkali is defined as a chemical substance that can dissolve in water to produce hydroxide ions, OH⁻. Bases and alkalis
A base is defined as a chemical substance which can react with an acid to form a salt and water. HCl + NaOH NaCl + H₂O
Thus, all oxide and hydroxide metals and ammonia are bases.
Most of the bases are insoluble in water .

Bases with are soluble in water are called alkalis.

An alkali is defined as a chemical substance that can dissolve in water to produce hydroxide ions, OH⁻. A substance has acidic properties because of the formation of H⁺ or hydroxonium ions, H₃O⁺ in water. The H⁺ cannot exists in aqueous solution but combines with a water molecule (hydrated) and form H₃O⁺. Hydrogen ions mean Hydroxonium ions. H₂O + H⁺ H₃O⁺

Acids can be divided into two types according to the elements contain. Mineral acids do not contain carbon but organic acids contain carbon element. Types of acid| Examples|
Mineral acid | HCl, H₂SO₄, HNO₃|
Organic acid| CH₃COOH, HCOOH, H₂C₂O₄|

A substance has acidic properties because of the formation of H⁺ or hydroxonium ions, H₃O⁺ in water. The H⁺ cannot exists in aqueous solution but combines with a water molecule (hydrated) and form H₃O⁺. Hydrogen ions mean Hydroxonium ions. H₂O + H⁺ H₃O⁺

Acids can be divided into two types according to the elements contain. Mineral acids do not contain carbon but organic acids contain carbon element. Types of acid| Examples|
Mineral acid | HCl, H₂SO₄, HNO₃|
Organic acid| CH₃COOH, HCOOH, H₂C₂O₄|

Indicator| Colour in|
| Acid| Alkali|
Litmus | Red| Blue|
Phenolphthalein| Colorless| Red/pink|
Methyl orange| Red| Yellow |

Indicator| Colour in|
| Acid| Alkali|
Litmus | Red| Blue|
Phenolphthalein| Colorless| Red/pink|
Methyl orange| Red| Yellow |

Basicity of an acid
An acid can be classified into monoprotic acid, diprotic acid, or tripotic acid based on its basicity. Basicity = the number of ionisable hydrogen atoms per molecule of an acid * Monoprotic acid HNO₃ (aq) H⁺(aq) + NO₃⁻(aq)

* Diprotic acid H₂SO₄ (aq) 2H⁺ (aq) + SO₄²⁻(aq)

* Tripotic acid H₃PO₄(aq) 3H⁺(aq) + PO₄³⁻ (aq)

Basicity of an acid
An acid can be classified into monoprotic acid, diprotic acid, or tripotic acid based on its basicity. Basicity = the number of ionisable hydrogen atoms per molecule of an acid * Monoprotic acid HNO₃ (aq) H⁺(aq) + NO₃⁻(aq)

* Diprotic acid H₂SO₄ (aq) 2H⁺ (aq) + SO₄²⁻(aq)

* Tripotic acid H₃PO₄(aq) 3H⁺(aq) + PO₄³⁻ (aq)

An alkali only shows its...
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