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Warm Up3-9-15 1.Write a scenario where energy is transferred (ex. making popcorn) 2.A hot frying pan is immersed in water. Describe how heat flows. 3.Turning gas to liquid a _____thermic reaction, because ________ Agenda Go over test Unit 3 Notes Unit 4 Specific Heat One-on-one grade check WS Specific heat Homework Finish WS
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TEST UNIT 3 Version 1 17. 5.28 atm 18. The heat from the road causes the air to move faster generating more collision and increases pressure. 19. Volume and temperature increases together 20. See board Version 2 17. The heat from the road causes the air to move faster generating more collision and increases pressure. 18. Volume and temperature increases together 19. 5.28 atm 20. See board
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Specific Heat Unit 4 Day 2
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Heat vs. Temperature Heat is energy, and temperature is a measurement of heat Heat is energy in transit –Flows from warm to cooler objects –Measured in joules (J) and calories (cal)
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Heat vs. Temperature -Temperature: the measure of the average kinetic energy of the random motion of particles in a substance –Kinetic Energy: energy of an object due to the object’s motion –The hotter the substance, the faster the particles are moving
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Heat vs. Temperature Measured in 3 different temperature scales: Fahrenheit, Celsius, and Kelvin Kelvin is based on absolute zero scale. At zero °Kelvin, all molecules froze & stop moving °K = °C + 273 °C = °K – 273°C = (°F – 32) x 5 ⁄ 9
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Heat vs. Temperature Celsius Scale –0 o C - water freezes/melts –100 o C - water boils Kelvin Scale –0 K- molecular motion stops, also known as absolute zero –0 Kelvin = –273 o C
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Transfer of heat does not always result in a temperature change (ΔT) Specific heat – the amount of energy required to raise 1 gram of a substance by one degree of temperature Water has a specific heat of 4.18 J/g·K Specific Heat
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CHECK IN The beaker and iron pan both have the same mass. Which will get hot first if the same amount of heat is applied to both?
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CHECK IN Which beaker will require more heat to boil? A B
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Calculating Specific Heat Different substances respond to heat transfer differently xx m x ΔT x C sp = Q SymbolUnit Massmg Change in temperature (T f – T i ) ΔTK or C Specific heatC sp J/g·K Heat energyQJoule
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Calculating Specific Heat Problems You are boiling 100 gram of water from room temperature at 25°C to 100°C. How much heat is required? xx m x ΔT x C sp = Q
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Calculating Specific Heat Problems 4 gram sample of glass was heated from 274 ° K to 314 °K and required 32 J of energy. Find the specific heat of this glass xx m x ΔT x C sp = Q
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Calculating Specific Heat Problems Determine the mass of a material its specific heat is 2 J/g·K sample absorbed 48.0 J as it was heated from 293 °K to 313 °K xx m x ΔT x C sp = Q
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Calculating Specific Heat Problems The specific heat of aluminum is 0.89 J/g o C. If 435 J of energy is added to 100g of aluminum. What is the ΔT?
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ASSIGNMENTS Look at your 1 st WU. What were your goals and things you’re going to do differently Notes Summary Worksheet Specific Heat
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