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Find energy supplied by electric current using W = IVt Grade 10 SABIS To find the energy supplied by an electric current, the equation W = IVt is utilized, where W represents the energy supplied, I is the current flowing through the circuit, V is the potential difference (voltage) across the circuit, and t is the time for which the current flows. The equation W = IVt is derived from the fundamental relationship between electrical power, current, voltage, and time. Power (P) is defined as the rate at which energy is transferred or consumed, and it can be calculated as the product of current and voltage, P = IV. Multiplying this power by time (t), we obtain the energy supplied or consumed, which is given by the equation W = IVt. The unit of current (I) is measured in amperes (A), the unit of voltage (V) is measured in volts (V), and the unit of time (t) is measured in seconds (s). For example, let's consider a scenario where a circuit has a constant current of 2 amperes (A) flowing through it, a voltage of 12 volts (V) across the circuit, and the current flows for a duration of 10 seconds (s). Using the equation W = IVt, we can calculate the energy supplied as follows: W = (2 A) * (12 V) * (10 s) = 240 joules (J) Therefore, in this case, the energy supplied by the electric current is 240 joules (J). It's important to note that this equation assumes that the current and voltage remain constant during the entire time period. In real-world scenarios, the current and voltage may vary over time, requiring more advanced calculations to determine the total energy supplied. The equation W = IVt is widely applicable in various electrical systems, such as household circuits, electronic devices, and power grids. It allows for the measurement and calculation of energy consumption or supply, enabling us to understand and analyze the energy usage and requirements of electrical systems. By utilizing the equation W = IVt, we can quantitatively assess the energy consumed or supplied by an electric current. This information is essential for managing energy resources, estimating costs, and optimizing energy efficiency in various applications. In summary, finding the energy supplied by an electric current involves using the equation W = IVt, where W represents the energy supplied, I is the current, V is the voltage, and t is the time. By multiplying the current, voltage, and time, we can determine the energy transferred or consumed. Understanding and calculating the energy supplied by electric current are essential in various fields, including electrical engineering, energy management, and sustainable technology.

Know what is meant by electrical work Grade 10 SABIS Electrical work in thermochemistry refers to the work done by or on a system as a result of the flow of electrical charges. It involves the transfer of energy through an electrical circuit and can have significant implications in various chemical and physical processes. When an electric current passes through a conductor, such as a wire, it involves the movement of charged particles, typically electrons. This movement of charges constitutes an electric current and results in the generation of electrical work. The electrical work done can be expressed mathematically using the equation W = IVt, where W represents the work done, I is the electric current, V is the potential difference (voltage), and t is the time over which the current flows. The magnitude of the electrical work done is determined by the product of the current, voltage, and time. A higher current or voltage, or a longer duration of current flow, results in a greater amount of electrical work. In thermochemistry, electrical work is particularly relevant in processes involving electrolysis, where chemical reactions are driven by the passage of an electric current. It is also significant in electrochemical cells, batteries, and other energy storage and conversion devices. For example, in the electrolysis of water, an electric current is passed through water, causing the water molecules to undergo a chemical reaction and separate into hydrogen and oxygen gases. The electrical work done in this process is required to drive the reaction and facilitate the decomposition of water. Understanding electrical work in thermochemistry enables the analysis of energy transformations and conversions involving electrical energy. It provides insights into the relationship between electricity and chemical reactions, and it plays a crucial role in various technological applications. It's important to note that electrical work is just one component of the overall energy changes in a system. It should be considered in conjunction with other forms of work, such as pressure-volume work or shaft work, to fully account for the total energy involved in a process. In summary, electrical work in thermochemistry refers to the work done by or on a system as a result of the flow of electrical charges. It involves the transfer of energy through an electrical circuit and is determined by the current, voltage, and time. Understanding electrical work is essential for analyzing energy transformations in electrochemical processes and other electrical applications.

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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

Inverse Proportion A relationship between two variables where an increase in one variable leads to a decrease in the other variable, and vice versa.

< Back Reaction kinetics Previous Next 🔬 Chapter 9: Rates of Reaction 🔬 Learning Outcomes 🎯: Understand reaction kinetics and the factors affecting the rates of chemical reactions. Recognize the role of surface area, concentration, temperature, and catalysts in reaction rates. Understand the concept of activation energy and its role in determining the rate of reaction. Differentiate between homogeneous and heterogeneous catalysts. Understand the Boltzmann distribution of molecular energies and how it changes with temperature. Factors Affecting Rate of Reaction 📈: Surface Area : Finely divided solids have a larger surface area, leading to more frequent collisions and a faster reaction rate. Concentration and Pressure : Higher concentration or pressure leads to more frequent collisions between reactant molecules, increasing the reaction rate. Temperature : At higher temperatures, molecules have more kinetic energy, leading to more frequent and successful collisions. Catalysts : Catalysts increase the rate of reaction by providing an alternative reaction pathway with a lower activation energy. Activation Energy ⚡: Activation energy is the minimum energy required by colliding particles for a reaction to occur. It acts as a barrier to reaction, and only particles with energy greater than the activation energy can react. Boltzmann Distribution 📊: The Boltzmann distribution represents the number of molecules in a sample with particular energies. At higher temperatures, the distribution changes, showing that more molecules have energy greater than the activation energy, leading to an increase in reaction rate. Catalysis 🧪: Catalysts lower the activation energy, allowing a greater proportion of molecules to have sufficient energy to react. Homogeneous catalysts are in the same phase as the reactants, while heterogeneous catalysts are in a different phase. Enzymes are biological catalysts that provide an alternative reaction pathway of lower activation energy.

Any reaction or process that releases heat energy Grade 10 SABIS SABIS Exothermic

7 calculate enthalpy changes from appropriate experimental results, including the use of the relationships q = mcΔT and ΔH = –mcΔT/n A Level Chemistry CIE Calculating enthalpy changes from experimental results is a fundamental aspect of thermochemistry. Two common relationships used in these calculations are q = mcΔT and ΔH = –mcΔT/n, where q represents the heat energy, m is the mass of the substance, c is the specific heat capacity, ΔT is the temperature change, ΔH is the enthalpy change, and n is the stoichiometric coefficient. The relationship q = mcΔT is utilized when determining the heat energy gained or lost by a substance during a temperature change. Here, q represents the heat energy, m is the mass of the substance, c is the specific heat capacity (which is the amount of heat energy required to raise the temperature of one unit mass of the substance by one degree Celsius or Kelvin), and ΔT is the change in temperature. For example, if we have a sample of water with a known mass and we measure the temperature change before and after a reaction, we can use q = mcΔT to calculate the heat energy gained or lost during the reaction. By substituting the values into the equation, we can determine the energy change associated with the reaction. On the other hand, the relationship ΔH = –mcΔT/n is used specifically for enthalpy changes in chemical reactions. Here, ΔH represents the enthalpy change, m is the mass of the substance, c is the specific heat capacity, ΔT is the temperature change, and n is the stoichiometric coefficient of the substance in the balanced chemical equation. This relationship is based on the principle of conservation of energy, where the heat energy gained or lost by one substance is equal to the heat energy gained or lost by another substance in the reaction. By applying this relationship and the known values of mass, specific heat capacity, temperature change, and stoichiometric coefficients, we can calculate the enthalpy change of the reaction. For instance, if we have a balanced chemical equation and experimental data that includes the temperature change and masses of the reactants or products, we can use ΔH = –mcΔT/n to determine the enthalpy change of the reaction. This equation allows us to relate the heat energy exchanged during the reaction to the stoichiometry of the balanced equation. It's important to ensure that the units of mass, specific heat capacity, and temperature are consistent when using these relationships. Additionally, proper consideration should be given to the direction and sign conventions for energy changes (whether heat is gained or lost) based on the system under study. By applying the relationships q = mcΔT and ΔH = –mcΔT/n, we can calculate enthalpy changes from experimental results, providing valuable insights into the energy transformations occurring in chemical reactions. These calculations enable us to quantify the energy changes associated with reactions and deepen our understanding of thermodynamic processes. In summary, calculating enthalpy changes from experimental results involves the use of relationships such as q = mcΔT and ΔH = –mcΔT/n. These equations allow us to determine the heat energy gained or lost during temperature changes and relate them to enthalpy changes in chemical reactions. By applying these relationships, we can quantify energy changes and expand our understanding of thermochemical processes.

cm³ Grade 10 SABIS SABIS A unit of volume equal to one cubic centimeter, equivalent to 1 milliliter.

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Sum of masses of nucleons in a nucleus is different from nuclear mass Grade 10 SABIS The sum of the masses of nucleons (protons and neutrons) in a nucleus is different from the nuclear mass. This distinction arises due to the concept of mass defect and the conversion of mass into energy, as described by Einstein's famous equation, E = mc^2. The sum of the masses of nucleons refers to the total mass of all protons and neutrons present in the nucleus of an atom. Each nucleon has a specific mass, which can be measured in atomic mass units (amu) or kilograms (kg). Adding up the individual masses of the nucleons gives us the total mass of the nucleus. However, when comparing the total mass of the nucleons to the actual nuclear mass, we observe a discrepancy. The nuclear mass is slightly lower than the sum of the masses of the individual nucleons. This phenomenon is known as mass defect. Mass defect occurs because the binding of nucleons in the nucleus involves the conversion of a small portion of mass into energy. According to Einstein's equation, the mass of a system is equivalent to the energy it contains. During the formation of the nucleus, some mass is converted into binding energy to hold the nucleons together. The binding energy, or the energy required to separate the nucleons in the nucleus, is released when the nucleus is formed. This energy contributes to the stability of the nucleus. Due to the conversion of mass into energy, the total mass of the nucleus is slightly less than the sum of the masses of the nucleons. The difference between the sum of the masses of nucleons and the nuclear mass is known as the mass defect. It represents the mass that has been converted into binding energy within the nucleus. The mass defect is typically measured in atomic mass units (amu) or kilograms (kg). The relationship between mass defect and binding energy is governed by Einstein's equation, E = mc^2. The mass defect corresponds to the energy released during the formation of the nucleus. It is directly proportional to the binding energy and can be calculated using the equation ΔE = Δmc^2, where ΔE represents the energy released and Δm represents the mass defect. The concept of mass defect and the conversion of mass into energy are fundamental in nuclear physics and have significant implications in various fields, including nuclear power generation, nuclear weapons, and understanding the stability and properties of atomic nuclei. In summary, the sum of the masses of nucleons in a nucleus is different from the nuclear mass due to the phenomenon of mass defect. The mass defect arises from the conversion of a small portion of mass into binding energy during the formation of the nucleus. This discrepancy reflects the release of energy and the stability of the nucleus. Understanding the distinction between the sum of nucleon masses and the nuclear mass is crucial in the study of atomic nuclei and nuclear processes.

< Back States of matter Previous Next 🔬 Chapter 5: States of Matter 🔬 Learning Outcomes 🎯: State the basic assumptions of the kinetic theory as applied to an ideal gas. Explain qualitatively in terms of intermolecular forces and molecular size, the conditions necessary for a gas to approach ideal behavior. State and use the general gas equation pV = nRT in calculations. Describe, using a kinetic-molecular model, the liquid state, melting, vaporization, and vapor pressure. Describe in simple terms the lattice structures of crystalline solids, including ionic, simple molecular, giant molecular, hydrogen bonded, or metallic. Discuss the finite nature of materials as a resource and the importance of recycling processes. Outline the importance of hydrogen bonding to the physical properties of substances, including ice and water. Recycling Materials ♻️: Recycling metals saves energy, conserves supplies of the ore, reduces waste, and is often cheaper than extracting metals from their ores. Recycling copper is important due to the low percentage of copper in most remaining ores and the energy savings in recycling compared to extraction. Recycling aluminum is much cheaper than extracting it from bauxite ore, and there is a 95% saving in energy by recycling aluminum compared to extracting it from its ore. The Gaseous State 💨: The kinetic theory of gases assumes that gas molecules move rapidly and randomly, the distance between gas molecules is much greater than the diameter of the molecules, there are no forces of attraction or repulsion between the molecules, and all collisions between particles are elastic. The Liquid State 💧: When a solid is heated, the energy transferred makes the particles vibrate more vigorously, the forces of attraction between the particles weaken, and the solid changes to a liquid (melting). In a liquid, particles are close together but have enough kinetic energy to slide past each other. Vaporization is the change from the liquid state to the gas state, and the energy required for this change is called the enthalpy change of vaporization. The Solid State 🧱: Solids have fixed shape and volume, with particles touching each other and usually arranged in a regular pattern. The state of a substance at room temperature and pressure depends on its structure and bonding, including simple atomic, simple molecular, giant ionic, giant metallic, and giant molecular structures.