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Heating Curve ​ ​ A graphical representation of the relationship between temperature and time as a substance is heated.

Effect of changing temperature on rate of reaction: Grade 10 SABIS ​ increasing the temperature increases the average kinetic energy of the reactant particles, the number of particles that collide with activation energy or more increases, thus the number of effective collisions increases and so does the rate. A second, not as important, effect is an increase in the collision frequency.

Reactivity of alkali metals increases as their atomic number increases. Grade 10 SABIS ​

Energy Conversion Grade 10 SABIS ​ Energy conversion refers to the process of transforming energy from one form to another. It involves the conversion of energy between different types, such as mechanical, electrical, thermal, chemical, or radiant energy. To understand energy conversion, let's consider an everyday example: a car. When you drive a car, the engine converts the chemical energy stored in fuel into mechanical energy to move the vehicle. Here, energy is transformed from the chemical form (fuel) to mechanical energy (motion). Another example of energy conversion is the use of solar panels to generate electricity. Solar panels convert radiant energy from the sun into electrical energy, which can be used to power homes, devices, or charge batteries. In a similar manner, a wind turbine converts the kinetic energy of the wind into electrical energy. The movement of the wind blades causes the rotor to spin, generating electricity through the conversion of kinetic energy to electrical energy. In thermodynamics, a steam power plant exemplifies energy conversion. Heat energy from burning fossil fuels or nuclear reactions is used to produce steam, which then drives a turbine to generate electrical energy. Here, the energy is converted from thermal energy to mechanical energy and finally to electrical energy. Energy conversion is also evident in the use of batteries. When you charge a battery, electrical energy from a power source is converted into chemical energy, which is stored in the battery for later use. When you use the battery, the stored chemical energy is then converted back into electrical energy. Furthermore, when you switch on a light bulb, electrical energy is converted into radiant energy (light) and thermal energy (heat) as the filament emits light and produces heat. In our bodies, food is converted into energy through a process called cellular respiration. The chemical energy stored in food molecules is transformed into usable energy in the form of adenosine triphosphate (ATP), which powers various biological processes. Energy conversion is essential in various industries and technologies. For example, in hydroelectric power plants, the potential energy of water stored in dams is converted into kinetic energy as it flows downhill, which is then transformed into electrical energy. In summary, energy conversion is the process of transforming energy from one form to another. Examples such as cars converting chemical energy to mechanical energy, solar panels converting radiant energy to electrical energy, and batteries converting electrical energy to chemical energy help illustrate the concept. Energy conversion plays a crucial role in various systems, technologies, and natural processes, enabling the utilization and transfer of energy in different forms for everyday applications.

Heating water from 20°C through to boiling continuously at 100°C Grade 10 SABIS SABIS Endothermic

Fractional Coefficients Grade 10 SABIS SABIS Coefficients in a chemical equation that are fractions, used to balance the equation.

Application on Hess’s Law Grade 10 SABIS ​ Question 1: Given the following reactions and their respective enthalpy changes: C(graphite) + O2(g) → CO2(g) ΔH1 = -393.5 kJ/mol CO(g) + 1/2O2(g) → CO2(g) ΔH2 = -283.0 kJ/mol C(graphite) + 1/2O2(g) → CO(g) ΔH3 = -110.5 kJ/mol Calculate the enthalpy change for the reaction: C(graphite) + 1/2O2(g) → CO2(g) Answer 1: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Adding reactions 2 and 3 gives: 2CO(g) + O2(g) → 2CO2(g) ΔH2 + ΔH3 = -283.0 kJ/mol + (-110.5 kJ/mol) = -393.5 kJ/mol Since this reaction is the reverse of reaction 1, the enthalpy change for the given reaction is the negative of ΔH1. ΔH = -(-393.5 kJ/mol) = 393.5 kJ/mol Question 2: Given the following reactions and their respective enthalpy changes: N2(g) + O2(g) → 2NO(g) ΔH1 = 180.6 kJ/mol 1/2N2(g) + O2(g) → NO2(g) ΔH2 = 33.2 kJ/mol Calculate the enthalpy change for the reaction: NO(g) + NO2(g) → N2O3(g) Answer 2: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add the enthalpy changes. Multiplying reaction 2 by 2 gives: N2(g) + 2O2(g) → 2NO2(g) 2ΔH2 = 2(33.2 kJ/mol) = 66.4 kJ/mol Adding reactions 1 and 2 gives: 2N2(g) + 2O2(g) → 4NO(g) 2ΔH1 + 2ΔH2 = 2(180.6 kJ/mol) + 66.4 kJ/mol = 427.6 kJ/mol Since this reaction is the reverse of the desired reaction, the enthalpy change for the given reaction is the negative of the calculated value. ΔH = -427.6 kJ/mol Question 3: Given the following reactions and their respective enthalpy changes: 2H2(g) + O2(g) → 2H2O(l) ΔH1 = -572 kJ/mol 2H2O(l) → 2H2(g) + O2(g) ΔH2 = 572 kJ/mol Calculate the enthalpy change for the reaction: H2(g) + 1/2O2(g) → H2O(l) Answer 3: To calculate the enthalpy change for the given reaction, we can use Hess's Law. By manipulating the given reactions, we can cancel out the common compounds and add

Subscript Grade 10 SABIS SABIS The number used after a chemical symbol to indicate the number of atoms present per molecule

Observations for the reaction of alkali metal with water: Grade 10 SABIS ​  Piece of metal floats (alkali metals have low density).  Piece of metal darts around.  A hissing sound is heard due to the evolution of a gas.  If red litmus paper is dipped in the solution, the paper turns blue due to the formation of the alkali metal hydroxide.  If few drops of phenolphthalein indicator are added to the water solution turns pink due to the formation of alkali metal hydroxide.  If the gas produced is tested with a lit splint, it burns with a squeaky pop sound.

Decomposition Grade 10 SABIS SABIS A chemical reaction in which a single compound breaks down into two or more simpler substances.

Recall the expressions for gravitational potential and kinetic energy of an object Grade 10 SABIS ​ 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.

Atoms or ions that have the same electron arrangement around their nuclei as the noble gases will be stable. Grade 10 SABIS ​