Secondary Catalogue

This programme is about seawater. It is the most important liquid on Earth, not only from its sheer volume, but also because it has remarkable qualities. A few of them, like buoyancy, are common to all liquids - but seawater is also the cradle of life. Three key factors of water underpin life in the sea: water’s dissolving power, its tendency to keep a stable temperature, and its transparency to light. This programme explains the mechanisms and the outcomes of these key facts—and other things—that make seawater both weird and wonderful. Show Less

Newton’s Third Law of Motion states that to every action there is an equal and opposite reaction. Newton’s Universal Law of Gravitation is equivalent to his Third Law of Motion in the sense that any two objects in the universe attract each other with forces which are equal in magnitude and opposite in direction. Show Less

The chemical reactivity of metals increases from the top to the bottom in a group, while the chemical reactivity of non-metals decreases as we move down in the group. On moving down in a group of the Periodic Table, there is no change in the nature of the oxides of the elements. Show Less

Fats are the nutrients which provide almost double the amount of energy as compared to carbohydrates. All types of oils and nuts, butter, milk and meat are excellent sources of fats. When eaten in excess, fats get stored in the liver, under the skin, and around the heart and the kidneys where it interferes with the normal functioning of these organs, leading to various diseases. Show Less

Moderately reactive metals are extracted from their metal oxides by the process called reduction. The reduction of metal oxides, by heating with carbon, in the form of coke, is called smelting, and the reduction of metal oxides to metal, using aluminium, is called an aluminothermite reaction. Show Less

Coal is a fossil fuel and mainly consists of carbon and small amounts of hydrogen, sulphur, oxygen and nitrogen. Heating coal, in the absence of air, is known as destructive distillation of coal. It yields various useful products like coke, coal gas, coal tar, and ammoniacal liquor. Show Less

On moving down in a group of the periodic table, the metallic character of the elements increases while their non-metallic character decreases. Metals have a tendency to lose electrons to form positive ions and are hence known as electropositive elements, while non-metals have tendency to gain electrons to form negative ions and hence are known as electronegative elements. Show Less

Liquids have a fixed volume but no fixed shape. The spaces between the particles in liquids are almost the same as in solids. However, the particles in liquids are free to move. The speed of the movement of the molecules in a liquid decreases with a decrease in temperature, and increases with an increase in temperature. Show Less

How is chemical equilibrium important for making ammonia? This video demonstrates how an understanding of chemical equilibrium and Le Chatelier’s principle is applied in the Haber-Bosch Process, making the production of ammonia more efficient. Clear explanations of the theory behind the process make this essential viewing for senior secondary chemistry students. Show Less

What happens when you add more product to an equilibrium? This video demonstrates how an increase in products affects reaction rates in accordance with Le Chatelier’s principle. Students will observe how the appearance of a solution of sodium chloride changes when products are added. Footage of a real lab demonstration makes this essential viewing for senior secondary chemistry students. Show Less

What is an equilibrium constant and how do we work it out? This video explains various aspects of the equilibrium constant, including what it is, how to calculate it and how it can be affected by other factors like temperature and pressure. Easy-to-understand explanations and worked-through examples of Kc calculations make this essential viewing for senior secondary chemistry students. Show Less

How is chemical equilibrium important for cellular respiration? This video explains how two competing equilibrium reactions involving haemoglobin are at work in the process of cellular respiration. Clear explanations of this life-or-death example of competing equilibria make this essential viewing for senior secondary chemistry students. Show Less

What happens when you increase the pressure on an equilibrium? This video demonstrates how changing pressure affects reaction rates in accordance with Le Chatelier’s principle. Students will observe the colour of a gaseous mixture of nitrogen dioxide and dinitrogen tetroxide under different pressure conditions. Footage of a real lab demonstration makes this essential viewing for senior secondary chemistry students. Show Less

What happens when you turn up the heat in an equilibrium? This video demonstrates how changing temperature affects reaction rates in accordance with Le Chatelier’s principle. Students will observe the colour of a solution of cobaltous chloride at different temperatures. Footage of a real lab demonstration makes this essential viewing for senior secondary chemistry students. Show Less