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< Back Chapter 3: Acids and Bases Dive into the world of acids and bases and discover the properties and reactions of different acids and bases. Chapter 3: Acids and Bases - This chapter covers the properties of acids and bases and their behavior in aqueous solution. Students will learn about pH, pOH, acid-base titrations, and buffer solutions. The chapter also covers the different theories of acid-base behavior and the strengths of acids and bases. Previous Next

6. The process of cooling liquid paradichlorobenzene until it Grade 10 SABIS SABIS

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Freezing/Solidification ​ ​ The change of a substance from a liquid to a solid state at a specific temperature.

Sublimation of iodine Grade 10 SABIS SABIS Endothermic

Electrical Work Grade 10 SABIS ​ Electric work is the energy supplied by an electric current. In thermochemistry, it refers to the energy transfer that occurs during an electrochemical reaction or when electrical energy is used to perform work. To understand electric work, let's consider an everyday example: charging a mobile phone. When you connect your phone to a charger, electrical energy flows from the power source to the phone's battery. This energy transfer allows the battery to store electrical energy, which can later be used to power the phone and perform various tasks. Similarly, when you plug in an electrical device such as a laptop or a blender, electric work is done to power the device and enable its functionality. The electrical energy supplied through the power cord allows the device to operate and perform the desired tasks. In thermochemistry, electric work is involved in various electrochemical processes. For instance, during electrolysis, an electric current is passed through a solution or molten compound, causing a chemical reaction to occur. This reaction is driven by the electric work performed, leading to the separation or deposition of substances. Consider the process of electroplating, where a thin layer of metal is deposited onto an object. By passing an electric current through a solution containing metal ions, the metal ions are reduced and form a solid metal layer on the object's surface. The electrical work is responsible for driving this electrochemical process. Electric work is also crucial in battery technology. When a battery is used to power a device, such as a flashlight or a remote control, electric work is done as the chemical reactions inside the battery generate an electric current. This current supplies the necessary energy for the device to function. In summary, electric work in thermochemistry refers to the energy transfer that occurs during electrochemical reactions or when electrical energy is used to perform work. Examples include charging a mobile phone, operating electrical devices, electrolysis, electroplating, and battery-powered devices. Understanding electric work helps explain the energy transformations involved in various electrochemical processes and the role of electrical energy in powering everyday devices.

At STP there are 10 gaseous elements. 5 monoatomic: helium(He), neon(Ne), argon(Ar), krypton(Kr), and xenon(Xe); 5 daitomic: fluorine(F2), chlorine(Cl2), oxygen(O2), hydrogen(H2) and nitrogen(N2) Grade 10 SABIS ​

< Back Equilibria ​ ​ Previous Next 🔬 Chapter 8: Equilibrium 🔬 Learning Outcomes 🎯:Explain what is meant by a reversible reaction and dynamic equilibrium.State Le Chatelier’s principle and apply it to deduce qualitatively the effect of changes in temperature, concentration, or pressure on a system at equilibrium.State whether changes in temperature, concentration, or pressure or the presence of a catalyst affect the value of the equilibrium constant for a reaction.Deduce expressions for equilibrium constants in terms of concentrations (Kc) and partial pressures (Kp).Calculate the value of equilibrium constants in terms of concentrations or partial pressures and the quantities of substances present at equilibrium.Describe and explain the conditions used in the Haber process and the Contact process.Show understanding of, and use, the Brønsted–Lowry theory of acids and bases.Explain qualitatively the differences in behavior between strong and weak acids and bases and the pH values of their aqueous solutions in terms of the extent of dissociation. Reversible Reactions and Dynamic Equilibrium 🔄:A reversible reaction is one in which the products can change back to reactants.Chemical equilibrium is dynamic because the backward and forward reactions are both occurring at the same time.A chemical equilibrium is reached when the rates of the forward and reverse reactions are equal. Le Chatelier’s Principle 📊:Le Chatelier’s principle states that when the conditions in a chemical equilibrium change, the position of equilibrium shifts to oppose the change.Changes in temperature, pressure, and concentration of reactants and products affect the position of equilibrium. Equilibrium Constants (Kc and Kp) 🧮:For an equilibrium reaction, there is a relationship between the concentrations of the reactants and products which is given by the equilibrium constant K.Equilibrium constants in terms of concentrations (Kc) and partial pressures (Kp) can be deduced from appropriate data. Brønsted–Lowry Theory of Acids and Bases 🧪:The Brønsted–Lowry theory of acids and bases states that acids are proton donors and bases are proton acceptors.Strong acids and bases are completely ionized in aqueous solution whereas weak acids and bases are only slightly ionized.Strong and weak acids and bases can be distinguished by the pH values of their aqueous solutions.🔍

Residue ​ ​ The solid substance left behind on the filter paper after filtration.

Amadeo Avogadro ​ ​ Italian chemist Amadeo Avogadro (1776-1856) Avogadro , in full Lorenzo Romano Amedeo Carlo Avogadro, conte di Quaregna e Cerreto , (born August 9, 1776, Turin, in the Kingdom of Sardinia and Piedmont [Italy]—died July 9, 1856, Turin), Italian mathematical physicist who showed in what became known as Avogadro’s law that, under controlled conditions of temperature and pressure, equal volumes of gases contain an equal number of molecules.

Know that a calorimeter is used to determine ΔH at constant V Grade 10 SABIS ​ Calorimeters are devices used in thermodynamics to measure the heat energy exchanged during a chemical or physical process. They are particularly useful in determining the change in enthalpy (ΔH) of a system. The statement "Know that a calorimeter is used to determine ΔH at constant V" means that a calorimeter is designed to measure the change in enthalpy at constant volume (V). In a constant volume calorimeter, the volume of the system remains constant throughout the process, allowing for the determination of ΔH under these specific conditions. When using a calorimeter to determine the heat of combustion of a substance with oxygen, we can obtain the ΔH for the substance at constant pressure (c). This is because combustion reactions typically occur under atmospheric pressure, and a constant pressure calorimeter is commonly used to measure the heat changes associated with these reactions. In a constant pressure calorimeter, the pressure remains constant throughout the process. This is achieved by using an open system or ensuring that the pressure inside the calorimeter is the same as the surrounding atmospheric pressure. By maintaining a constant pressure, the heat exchange can be accurately measured and used to determine the enthalpy change (ΔH) for the substance. The option (c) ΔH for the substance at constant pressure aligns with the concept of using a calorimeter to determine the heat of combustion. It takes into account the fact that combustion reactions usually occur at constant atmospheric pressure and can be accurately measured in a constant pressure calorimeter. The other options can be eliminated as follows: Option (a) ΔH for a constant mass of the substance is not necessarily true because the mass of the substance may change during the combustion process. Option (b) ΔH for the substance at constant temperature is not accurate because the temperature may change during the combustion process. Option (d) ΔH for the substance at constant volume is not applicable as the volume usually changes during the combustion process. Option (e) ΔH for the substance at constant product PV is not directly related to the use of a calorimeter in determining the heat of combustion. In summary, a calorimeter is used to determine the change in enthalpy (ΔH) at constant volume (V). When using a calorimeter to measure the heat of combustion of a substance with oxygen, the ΔH for the substance can be determined at constant pressure (c). This is achieved using a constant pressure calorimeter, which allows for accurate measurement of the heat exchange during the combustion process.

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