In this series of videos, we will go through the top 40 chemical substances all students must know.
Part 1 – First 20 Chemical Substances
Part 2 – Next 20 Chemical Substances
Part 3 – Revision : Go through worksheet focusing on the chemical formulas of the chemical substances
Video Part 1 – with subtitles
- Hydrogen is colourless, odourless and neutral. It is the lightest gas and highly flammable.
- Oxygen is a neutral and odourless gas. It supports oxidation and combustion.
- Nitrogen is the most abundant gas. It is colourless and odourless. This gas is quite chemically inert.
- Fluorine (pale yellow gas at r.t.p)
- Chlorine (greenish yellow gas at r.t.p) In the test for chlorine gas, the moist blue litmus paper turns red, then bleaches.
- Bromine (reddish brown liquid at r.t.p)
- Iodine (purplish black solid at r.t.p)
- Ozone is an allotrope of oxygen. It is a pale blue gas with a pungent odour.
- Water exists as liquid at r.t.p, and freezes into ice at 0°C, boils into steam at 100°C. Water expands when it freezes.
- Methane (main component of natural gas) is a colourless and neutral gas.
- Ammonia is a colourless and alkaline gas. Ammonia gas turns moist red litmus paper blue.
- Carbon monoxide is a colourless and neutral gas. It is poisonous.
- Carbon dioxide is the colourless gas that we breathe out. Unpolluted rainwater has a pH of around 5.6 due to carbon dioxide gas, which is an acidic gas.
- Carbonic acid – Carbon dioxide dissolves in rainwater to form weak carbonic acid.
- Calcium hydroxide, also known as limewater in Chemistry lab, is an alkali used to test for acidic carbon dioxide gas. In agriculture, calcium hydroxide is known as slaked lime.
- Calcium oxide – To reduce the acidity of soil, calcium hydroxide (slaked lime), or calcium oxide (quicklime) is added to the soil.
- Sulfur dioxide is pungent, chocking and colourless. Sulfur dioxide is an acidic gas. It dissolves in water to form sulfurous acid.
- Sulfurous acid is then oxidised to sulfuric acid by oxygen. Presence of sulfur dioxide in the atmosphere gives rise to acid rain. Sulfur dioxide pollution can be reduced by flue gas desulfurisation.
- Hydrogen chloride is a colourless and acidic gas. It dissolves in water to form hydrochloric acid, which is a strong acid.
- Hydrochloric acid – Hydrogen ions and chloride ions are released in the aqueous solution. Hydrochloric acid is used to clean impurities.
Video Part 2 – with subtitles
- Sulfuric acid is one of the widely used acids.
- Nitric acid is important industrial chemical.
- Phosphoric(V) acid is added to food and beverages.
- Sodium hydroxide, a common alkali, is also known as lye or caustic soda.
- Sodium chloride
- Carbon (Coke) acts as a reducing agent.
- Iron(III) oxide – The main ore of iron is haematite.
- Calcium silicate (Slag) – In the blast furnace, useful product like slag can be formed. Slag is commonly used in construction.
- Calcium carbonate is a white solid at r.t.p.
- Silicon dioxide (Silica) is a solid at r.t.p. It is an acidic oxide. It has giant molecular structure.
- Ethanol can be made through fermentation process.
- Ethanoic acid (Dilute solution of Vinegar) is a colourless liquid at r.t.p and has characteristic smell of vinegar.
- Glucose – During photosynthesis, green plants convert carbon dioxide and water into glucose and oxygen. During respiration, glucose is converted into energy, carbon dioxide and water.
- Hydrated copper(II) sulfate (blue crystals)
- Anhydrous copper(II) sulfate (white powder)
- Nitrogen monoxide (Nitric oxide) is colourless, odourless, neutral and water insoluble.
- Nitrogen dioxide is a reddish brown and odourless gas which gives rise to acid rain.
- Acidified potassium manganate (VII), is a common oxidising agent.
- Potassium iodide, is a common reducing agent.
- Hydrogen peroxide acts as oxidising or reducing agent. It is commonly used as bleaching agent and antiseptic.
Video Part 3 – with subtitles