Lesson Note on Chemistry SS1 Third Term

 SCHEME OF WORK

 

SS1 CHEMISTRY THIRD TERM: ACIDS (ORGANIC AND INORGANIC)

ACIDS

BASES AND ALKALIS

SALTS

ACIDITY AND ALKALINITY

CARBON

OXIDES OF CARBON

TRICARBONATES

HYDROCARBONS

CHEMICAL INDUSTRIES

Chemistry Lesson Note For SS1 (Third Term) 

Below are the 2022 complete Chemistry lesson notes for SS1 Third Term

 

Week 1

Topic: Acids

Acids have long been associated with the sour taste of some fruits such as lime and lemon. Their ability to change litmus solution from blue to red is well known. There are two classes of acids – organic and inorganic acids. The former occurs as a natural product in plants and animals while the latter can be prepared from mineral elements or inorganic matter. An organic acid is an organic substance that has the properties of an acid, while inorganic acids, also known as mineral acids, come from inorganic substances. Some examples of inorganic acids include sulphuric acid, hydrochloric acid, nitric acid, boric acid and hydrofluoric acid.

Mineral/Inorganic Acids

• They are generally much stronger
• Most do not occur naturally
• They usually have simpler molecules. To learn more, Click here. 

Week 2

Topic: Acids

Introduction

Acids form a class of chemical substances which contain hydrogen ions in aqueous solution, H⁺ (aq), as the only positive ion. Acids are usually classified into mineral (Inorganic) or organic acids. An acid is a substance which produces hydrogen ions or protons as the only positive ion when dissolved in water. Acids dissolve in water to produce hydrogen ions H⁺ as the only positive ions together with the corresponding negative ions. This process is known as ionization.

Acids in Solution

Acids are substances that form hydrogen ions when dissolved in water. A hydrogen ion is actually a proton. Therefore, acids are called proton donors.

Strong Acids ionize completely in water to give hydrogen ions and anions. The concentration of hydrogen ions is very high in such acid solutions. To learn more, Click here. 

Week 3

Topic: Bases and Alkalis

Introduction

Bases are substances that, in aqueous solution, are slippery to the touch, taste bitter, change the colour of indicators (e.g., turn red litmus paper blue), react with acids to form salts, and promote certain chemical reactions (base catalysis). Bases are usually metallic oxides or metallic hydroxides.

Bases that are soluble in water are called alkalis.

 

In an aqueous solution, alkali produces hydroxide ions (OH^–). In short, alkalis are substances that form hydroxide ions (OH^–(aq)) in water. To learn more, Click here. 

Week 4

Topic: Salts

Introduction
A salt is an ionic compound formed when the hydrogen of an acid is partly or completely replaced by a metal ion or ammonium ion. All salts are chemically and electrically neutral.
Example:

The diagram above shows that when the hydrogen ion in nitric acid is replaced by Na⁺, Ca²⁺, NH₄⁺ or Al³⁺ ions, salts are formed. To learn more, Click here. 

Week 5

Topic: Alkalinity and Acidity

Content

1. Alkalinity and Acidity
2. Calculations of pH and pOH
3. Indicators
4. Hygroscopy
5. Drying Agents

Alkalinity and Acidity

Alkalinity and Acidity are measured using a scale of numbers from 0 to 10 called the pH scale. A solution with pH value of 7 is neutral. A solution with a pH value less than 7 is acidic while a solution with pH value greater than 7 is alkaline. Acidity increases with decreasing pH while alkalinity increases with increasing pH. 

Dissociation of water

Water is neutral and it ionizes very slightly to yield an equal number of hydrogen ions and hydroxide ions. 

[H⁺] = [OH^–] = 1 x 10^-7 mol dm^-3 (at 25^oC) To learn more, Click here. 

Week 6

Topic: Carbon

Introduction

Carbon forms the largest number of compounds, next only to hydrogen. It ranks seventeenth in the order of abundance in the earth’s crust. Carbon occurs in the free native state as well as in the combined state. Carbon and its compounds are widely distributed in nature.

In its elemental form, carbon occurs in nature as diamond and graphite. Coal, charcoal and coke are impure forms of carbon. The latter two are obtained by heating wood and coal in the absence of air, respectively. In the combined state, carbon is present as carbonate in many minerals, such as hydrocarbons in natural gas, petroleum etc. In air, carbon dioxide is present in small quantities, (0.03%).

Our food also contains carbon in the combined form. All living systems contain carbon compounds. Indeed, life as we know today, would be impossible without such carbon compounds.

Carbon is a non-metallic element and the first member of group 4 of the periodic table. To learn more, Click here. 

Week 7

Topic: Oxides of Carbon

Introduction

Carbon forms two important oxides, namely  carbon (iv) oxide and carbon (ii) oxide. The atmosphere contains about 0.03% by volume of carbon(iv) oxide. A small percentage of carbon (iv) oxide is found in the dissolved form of water. In the combined form, it is found mainly as metallic trioxocarbonates(iv) and hydrogen trioxocarbonates (iv) in the earth’s crust. 

Carbon (ii) Oxide

Carbon (II) oxide, also known as carbon monoxide, exhibits an oxidation state of +2. It is the choking gas produced during the incomplete combustion of gasoline in car engines. Carbon monoxide is a colourless, odourless, and tasteless gas that is slightly less dense than air. To learn more, Click here. 

Week 8

Topic: Trioxocarbonates

Introduction

These are the salts of carbonic acid. The anions are represented as:

• Carbonate ion trioxocarbonate (IV) : CO₃^2-
• Bicarbonate ion or hydrogen trioxocarbonates:  HCO₃^–

These anions are formed from carbonic acid, H₂CO₃ as follows:

H₂CO₃ <——-> HCO₃^– + H⁺ <——–> CO₃^2- + H⁺

To learn more, Click here. 

Week 9

Topic: Hydrocarbons

Introduction

Hydrocarbons are any organic compounds that contain only carbon and hydrogen

Hydrocarbons as a source of energy

Hydrocarbons are energy-rich because of their high carbon content. They are burned in oxygen (combustion) to release their energy.

Crude oil, or petroleum, is the main source of liquid hydrocarbons. Crude oil is a mixture of various hydrocarbons, which can be separated via fractional distillation.

These components have distinct uses, from providing energy for cooking to lubricating machine parts.

Natural gas mainly contains methane, which is the smallest hydrocarbon. To learn more, Click here. 

Week 10

Topic: Chemical Industries 

The development of the chemical industry had important effects on chemistry. In 1749, the Chamber process for the commercial manufacture of hydrogentetraoxosulphate (vi) was developed. 

Important Raw Materials

The important raw materials are air, sea water and rock salt, sulphur, calcium trioxocarbonate (IV), metallic mineral ores, coal, natural gas and petroleum. Most of the naturally occurring raw materials are themselves chemicals which are used as starting materials to produce other chemicals and products on a large scale. All these important raw materials except air are mined from the earth’s crust. Salt is obtained mainly from seawater. To learn more, Click here.