Purity, Formulations & Chromatography: Chromatography 🧪 GCSE Chemistry Learning & Revision

This episode discusses how to identify halides. To identify halide ions, in a solution, a two-step process is employed. First, dilute nitric acid is added to eliminate any carbonate ions that could interfere with the subsequent test. Following this, silver nitrate is introduced. The presence of halide ions is indicated by the formation of a precipitate; silver chloride appears white, silver bromide is cream-coloured, and silver iodide presents pale yellow. These observations allow for the identification of the specific halide anion present.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss chromatography.Chromatography is a technique used to separate the components of a mixture. This process relies on two phases: a mobile phase that carries substances and a stationary phase that impedes their movement. The separation occurs because different substances have varying affinities for these two phases. If a substance is more attracted to the mobile phase, it travels further; conversely, greater attraction to the stationary phase results in less movement. The effectiveness of separation can be influenced by the solvent used as the mobile phase.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we talk about addition polymerisation.Addition polymerisation is a process where numerous short-chain monomers, specifically alkenes, combine to form a single long-chain polymer. This occurs because the carbon-carbon double bonds in the alkene monomers break, enabling them to link together. Notably, the resulting polymer is the sole product of this reaction, meaning its repeating unit possesses the same atoms as the initial monomer. Naming these polymers involves prefixing 'poly' to the bracketed name of the starting monomer, as illustrated by the formation of poly(ethene) from ethene and poly(propene) from propene.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

This episode outlines the fundamental aspects of carboxylic acids. We begin by listing and providing the chemical formulas for the four smallest carboxylic acids in order of increasing size: methanoic, ethanoic, propanoic, and butanoic acids. We then describes typical chemical reactions that carboxylic acids undergo. These reactions include interactions with carbonates, resulting in a salt, carbon dioxide, and water, as well as their dissolution in water to form acidic solutions. Finally, the text explains that carboxylic acids react with alcohols in the presence of an acid catalyst to produce esters and water, illustrated with the example of ethanoic acid and ethanol forming ethyl ethanoate and water.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss fermentation.Fermentation, a common method for making ethanol, a key ingredient in alcoholic beverages, is detailed. The process involves adding yeast to a sugary liquid. This results in a reaction that yields ethanol in a water-based solution and carbon dioxide. Optimal conditions for this process include a temperature of 37°C, a slightly acidic environment, and the absence of oxygen. In essence, the episode outlines the fundamental process and necessary conditions for producing ethanol through fermentation.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss reactions of alcohols.Alcohols exhibit consistent reactivity with various substances. When mixed with water, they form neutral solutions. Their reaction with sodium yields hydrogen gas. Strong oxidising agents transform alcohols into carboxylic acids. Finally, in the presence of air and heat, alcohols undergo complete combustion, producing carbon dioxide and water, as exemplified by the provided equation for methanol.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss alcohol and the smallest alcohols.Alcohols are organic compounds characterised by the presence of a hydroxyl group (-OH). They form a homologous series with a general chemical formula of CnH2n+1OH. The episode specifically outlines the four smallest members of this series. These are presented in order of increasing size: methanol (CH3OH), ethanol (CH3CH2OH), propanol (CH3CH2CH2OH), and butanol (CH3CH2CH2CH2OH). The information therefore serves as a basic introduction to the structural features and initial members of the alcohol family.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss fractional distillation, a method for separating hydrocarbons found in crude oil based on their varied boiling points. The process begins with heating crude oil to create a vapour, which then enters a fractionating column. As the vapour rises, different-sized hydrocarbons condense at different temperature levels, with longer chains condensing lower down due to their higher boiling points, and shorter chains condensing higher up. These collected fractions can then be used as fuels or as feedstock for the petrochemical industry to produce other materials.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss the properties of hydrocarbons.Hydrocarbon characteristics are directly influenced by their chain length. Specifically, longer hydrocarbon chains exhibit elevated boiling points and increased viscosity, meaning they are thicker and less prone to flow. Conversely, hydrocarbons with extended chains demonstrate reduced flammability. Therefore, the size of a hydrocarbon molecule is a key determinant of its physical and chemical behaviours, particularly regarding its suitability as a fuel source.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!

In this episode, we discuss conditions and equilibrium in a reversible reaction.Reversible reactions reach a state of equilibrium, where the amounts of reactants and products remain constant. Altering the conditions of such a system will disrupt this balance. Le Chatelier's principle explains that the system will respond in a way that opposes the imposed change, attempting to re-establish equilibrium. This principle serves as a tool for predicting how a system at equilibrium will shift when subjected to new conditions. The analogy of falling off and then successfully mounting a horse illustrates the system's tendency to return to a state of balance after a disturbance.Don't miss out on subscribing for more educational content tailored to help you succeed in your exams. Perfect for AQA, OCR, Edexcel, CIE and WJEC exam boards.⁠Click here to see all of our GCSE Chemistry content!