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

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

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

What happens when you remove products from an equilibrium? This video demonstrates how a decrease in the amount of product affects reaction rates in accordance with Le Chatelier’s principle. Students will observe how the appearance of a solution of zinc hydroxide changes when hydrochloric acid are added. Footage of a real lab demonstration makes this essential viewing for senior secondary chemistry students. Show Less

What does Le Chatelier have to do with chemical equilibrium? This shows how various changes can affect the balance of a reaction in equilibrium and favour one reaction over another, as predicted by Le Chatelier’s principle. Easy-to-understand explanations and clear examples make this essential viewing for senior secondary chemistry students. Show Less

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

What does it mean if a reaction is in equilibrium? This video introduces key concepts such as reversible and irreversible reactions, forward and reverse reactions and equilibrium. Easy-to-understand explanations and examples of chemical equilibria in daily life make this essential viewing for senior secondary chemistry students. Show Less

The majority of today’s astronomers and scientists support the theory we call the Big Bang. But what does the theory actually entail? How did it develop? Who was Edwin Hubble and what are spectral lines? In this film, we explore the background of the Big Bang theory. Was it really a bang? What different substances and particles were formed right after the Big Bang? We will explore these things. We will also find out how nebulas, stars, planets and solar systems were created. And finally, we will learn what evidence exists that supports this theory. What evidence is there that the Big Bang theory could be true? Show Less

Nucleophilic substitution is a reaction in which an electron rich group, called nucleophile, substitutes an outgoing group called leaving group, which carries with it the bonding electron pair. Good leaving groups are weak bases.Alkyl halides undergo nucleophilic substitution with various nucleophiles to form alcohols, ethers, esters, thiols, sulphides, amines, azides and nitriles Show Less

A balanced chemical equation represents the relative number of the reactant and product species taking part in a reaction. The ratio of the number of moles of any two substances in a chemical reaction is called their mole ratio. The mole ratio is a conversion factor that allows for the conversion between the moles of one substance to the moles of another. Show Less

According to the law of definite proportions ’A chemical compound always contains exactly the same proportion of elements by weight’. In the compound water, obtained from any source, such as rain or a river, the masses of hydrogen and oxygen are always in the ratio of 1:8. The law can be verified experimentally in a laboratory. Copper oxide prepared by different methods contains copper and oxygen in a fixed proportion by weight. Show Less

Substitution nucleophilic bimolecular or SN2 reactions occur in a single step. In this reaction, both bond - making and bond - breaking occur at the same time. It’s a second order or bimolecular reaction, in which the rate of the reaction depends upon the concentration of two reactants. The order of the reactivity of the alkyl halides in SN2 reactions increases from the tertiary alkyl halides to the primary alkyl halides. Show Less

The anti-Markovnikov rule describes the regiochemistry where the substituent is bonded to a less substituted carbon, rather than the more substitued carbon. This process is quite unusual, as carboncations which are commonly formed during alkene, or alkyne reactions tend to favor the more substitued carbon. Show Less

In the E-Z system for geometric isomers, if two groups or atoms of higher priority are on the same side of the double bond, then they are called Z isomers, and when they are on the opposite sides of the double bond, then they are called E isomers. The priority of groups or atoms is decided on the basis of the Cahn-Ingold-Prelog rules. Show Less

This video covers a number of different chemical reactions that carbon compounds can have. Carbon compounds can undergo combustion, substitution, addition, and oxidisation reactions. The video also looks at chemical reactions that ethanol and ethanoic acid can undergo. Show Less

This video introduces hydrocarbons, and highlights the difference between saturated and unsaturated hydrocarbons. It also introduces the International Union of Pure and Applied Chemistry naming conventions for straight chained hydrocarbons, branched-chain saturated hydrocarbons, and organic compounds containing the halo, alcohol, aldehyde, ketone, and carboxylic groups. Show Less

Carbon is a versatile element. Its tetravalent nature, to form strong covalent bonds and the property of catenation enables it to form a large number of compounds. This video introduces covalent bonds and their properties, with a focus on how carbon compounds bond, Show Less

In this video students will learn about functional groups, the atom or groups of atoms that give a characteristic property to a compound. The video also introduces homologous series—organic compounds that have similar structures—and isomers—compounds with the same molecular formula but different chemical structures. Show Less