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fe176007-4e3a-46ed-b793-ee7a9cdf64c4 comparing physical and chemical changes Summary Physical Change Does not produce a new kind of matter Is generally easily reversible Is not accompanied by great heat change Does not produce an observable change in mass Chemical Change Always produces a new kind of matter Is generally not easily reversible Is usually accompanied by considerable heat change Produces an observable change in mass Some examples of physical changes include: Melting ice Boiling water Cutting paper Crushing a rock Mixing salt and water Some examples of chemical changes include: Burning wood Cooking food Rusting iron Digesting food Brewing beer

6c42da10-353f-4cf5-bc39-e6b1c3ba2a58 Recall the expressions for gravitational potential and kinetic energy of an object Summary Gravitational Potential Energy: Gravitational potential energy is the energy possessed by an object due to its position in a gravitational field. The expression for gravitational potential energy (PE) is given by the equation: PE = mgh where m represents the mass of the object, g represents the acceleration due to gravity, and h represents the height or vertical distance of the object from a reference point. For example, if we consider a ball of mass m that is lifted to a height h above the ground, the gravitational potential energy of the ball is given by the product of its mass, the acceleration due to gravity, and the height it is lifted to. Kinetic Energy: Kinetic energy is the energy possessed by an object due to its motion. The expression for kinetic energy (KE) is given by the equation: KE = (1/2)mv^2 where m represents the mass of the object and v represents the velocity of the object. If we consider the same ball that was lifted to a height and then released, as it falls downward, its potential energy is converted into kinetic energy. The kinetic energy of the ball is given by half the product of its mass and the square of its velocity. The expression for kinetic energy shows that the kinetic energy of an object is proportional to its mass and the square of its velocity. This means that an object with a larger mass or a higher velocity will possess more kinetic energy. It's important to note that both gravitational potential energy and kinetic energy are scalar quantities, meaning they have magnitude but no specific direction. They are both measured in units of energy, such as joules (J). In summary, the expressions for gravitational potential energy and kinetic energy provide insights into the energy possessed by an object. Gravitational potential energy is determined by the mass of the object, the acceleration due to gravity, and its height from a reference point. Kinetic energy, on the other hand, depends on the mass of the object and its velocity. Understanding these expressions helps us analyze and quantify the energy changes associated with the position and motion of objects in various scenarios.

321f9bcf-34b5-4b82-803f-7215e00967a2 Halogens: F2 (Z = 9), Cl2 (Z = 17), Br2 (Z = 35) and I2 (Z = 53). Summary

f0561c56-ddc4-4bb6-859f-8bec022f3619 Effect of changing pressure on rate of reaction: Summary if one or more of the reactants are gaseous, an increase in pressure will increase their concentration. Increasing the concentration, increases the number of particles in a given volume thus the reacting particles will collide more frequently so the number of collisions will increase per unit time, thus rate of reaction increases. Pressure can be increased by either injecting more gas or by decreasing the volume of vessel in which the reaction is occurring.

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ffb25afd-266c-4c17-9944-647001834380 RTP (Room Temperature and Pressure) Summary A set of conditions close to room temperature (25°C) and atmospheric pressure used for experimental measurements.

59fc6c6e-346d-47f9-b0a9-da036389c1e1 Graphite is a solid non-metal element which is brittle yet conducts electricity Summary

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f406f7c0-d41d-43f1-89d7-4c7027b4a3e2 Collision Theory: SABIS Summary 1) For a reaction to proceed, particles of reactants must collide with one another.2) Particles must collide with the minimum amount of energy needed to react called the activation energy. Such collisions are called effective or successful collisions.3) To increase the rate of a chemical reaction, it is required to increase the frequency of effective collisions, i.e increase the number of successful collisions per unit time.

< 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.🔍