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Acetic Acid1960Jkg-1K-1Acetone2210Jkg-1K-1Acetylene1590Jkg-1K-1Aluminium900Jkg-1K-1Americium140Jkg-1K-1Ammonia2190Jkg-1K-1Antimony209Jkg-1K-1Argon519Jkg-1K-1Arsenic326Jkg-1K-1Asbestos1050Jkg-1K-1Asphalt920Jkg-1K-1Astatine140Jkg-1K-1Bakelite1600Jkg-1K-1Bar

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Presentation on theme: "Acetic Acid1960Jkg-1K-1Acetone2210Jkg-1K-1Acetylene1590Jkg-1K-1Aluminium900Jkg-1K-1Americium140Jkg-1K-1Ammonia2190Jkg-1K-1Antimony209Jkg-1K-1Argon519Jkg-1K-1Arsenic326Jkg-1K-1Asbestos1050Jkg-1K-1Asphalt920Jkg-1K-1Astatine140Jkg-1K-1Bakelite1600Jkg-1K-1Bar"— Presentation transcript:

1 Acetic Acid1960Jkg-1K-1Acetone2210Jkg-1K-1Acetylene1590Jkg-1K-1Aluminium900Jkg-1K-1Americium140Jkg-1K-1Ammonia2190Jkg-1K-1Antimony209Jkg-1K-1Argon519Jkg-1K-1Arsenic326Jkg-1K-1Asbestos1050Jkg-1K-1Asphalt920Jkg-1K-1Astatine140Jkg-1K-1Bakelite1600Jkg-1K-1Barium192Jkg-1K-1Benzene1700Jkg-1K-1Beryllium1820Jkg-1K-1Bismuth121Jkg-1K-1Boron1030Jkg-1K-1Brass370Jkg-1K-1Bromine448Jkg-1K-1Bronze360Jkg-1K-1Cadmium230Jkg-1K-1Caesium234Jkg-1K-1Calcium653Jkg-1K-1Carbon711 graphite, 519 diamondJkg-1K-1Carbon Dioxide834Jkg-1K-1Carbon Disulphide1000Jkg-1K-1Carbon Monoxide1050Jkg-1K-1Carbon Tetrachloride840Jkg-1K-1Cerium184Jkg-1K-1Chlorine477Jkg-1K-1Chloroform960Jkg-1K-1Chromium448Jkg-1K-1Cobalt435Jkg-1K-1Concrete3350Jkg-1K-1Copper385Jkg-1K-1Cork2050Jkg-1K-1Cyanogen1720Jkg-1K-1Dysprosium172Jkg-1K-1Erbium167Jkg-1K-1Ethanol2940Jkg-1K-1Ethylene1500Jkg-1K-1Europium138Jkg-1K-1Fluorine824Jkg-1K-1Francium140Jkg-1K-1Fused Silica703Jkg-1K-1Gadolinium234Jkg-1K-1Gallium381Jkg-1K-1Germanium322Jkg-1K-1Glassflint 500 crown 670 pyrex 753Jkg-1K-1Glycerol2400Jkg-1K-1Gold130Jkg-1K-1Graphite838Jkg-1K-1Hafnium146Jkg-1K-1Helium Jkg-1K-1Holmium163Jkg-1K-1Hydrogen14300Jkg-1K-1Hydrogen Chloride796Jkg-1K-1Hydrogen Sulphide1020Jkg-1K-1Ice2100Jkg-1K-1Indium238Jkg-1K-1Invar460Jkg-1K-1Iodine218Jkg-1K-1Iridium134Jkg-1K-1Iron448Jkg-1K-1Krypton247Jkg-1K-1Lanthanum201Jkg-1K-1Lead130Jkg-1K-1Lithium3390Jkg-1K-1Lutetium155Jkg-1K-1Magnesium1030Jkg-1K-1Magnesium Oxide960Jkg-1K-1Manganese477Jkg-1K-1Marble880Jkg-1K-1Mercury Hg138Jkg-1K-1Methane2200Jkg-1K-1Methyl Alcohol2500Jkg-1K-1Molybdenum251Jkg-1K-1Neodymium188Jkg-1K-1Neon1030Jkg-1K-1Nickel439Jkg-1K-1Niobium264Jkg-1K-1Nitric Oxide972Jkg-1K-1Nitrobenzene1400Jkg-1K-1Nitrogen1040Jkg-1K-1Nitrous Oxide892Jkg-1K-1Nylon1700Jkg-1K-1Oak2390Jkg-1K-1Olive Oil1970Jkg-1K-1Osmium130Jkg-1K-1Oxygen916Jkg-1K-1Palladium243Jkg-1K-1Paraffin Oil2130Jkg-1K-1Paraffin Wax2140 to 2900Jkg-1K-1Petroleum2140Jkg-1K-1Phenol2350Jkg-1K-1Phosphorus757 white, 670 redJkg-1K-1Platinum134Jkg-1K-1Polonium126Jkg-1K-1Polycarbonate1200 to 1300Jkg-1K-1Polymethyl Methacrylate Resin1500Jkg-1K-1Polystyrene1300Jkg-1K-1Polytetrafluoroethylene1040Jkg-1K-1Polyvinyl Chloride900Jkg-1K-1Porcelain920Jkg-1K-1Potassium753Jkg-1K-1Praseodymium192Jkg-1K-1Promethium184Jkg-1K-1Protactinium121Jkg-1K-1Quartz710Jkg-1K-1Radium121Jkg-1K-1Radon92Jkg-1K-1Rhenium138Jkg-1K-1Rhodium243Jkg-1K-1Rubidium360Jkg-1K-1Ruthenium238Jkg-1K-1Samarium197Jkg-1K-1Sand796Jkg-1K-1Scandium556Jkg-1K-1Sea Water3900Jkg-1K-1Selenium322Jkg-1K-1Silicon711Jkg-1K-1Silver234Jkg-1K-1Silver Bromide292Jkg-1K-1Sodium1230Jkg-1K-1Sodium Chloride854Jkg-1K-1Sodium I Fluoride1088Jkg-1K-1Soft Solder176Jkg-1K-1Stainless Steel510Jkg-1K-1Steel420Jkg-1K-1Strontium284Jkg-1K-1Sulphur732Jkg-1K-1Sulphur Dioxide645Jkg-1K-1Tantalum138Jkg-1K-1Technetium243Jkg-1K-1Tellurium201Jkg-1K-1Terbium184Jkg-1K-1Thallium130Jkg-1K-1Thorium113Jkg-1K-1Thulium159Jkg-1K-1Tin218Jkg-1K-1Titanium523Jkg-1K-1Toluene1670Jkg-1K-1Tungsten134Jkg-1K-1Turpentine1760Jkg-1K-1Uranium117Jkg-1K-1Uranium Oxide240Jkg-1K-1Vanadium481Jkg-1K-1Water4190Jkg-1K-1Xenon159Jkg-1K-1Ytterbium146Jkg-1K-1Yttrium297Jkg-1K-1Zinc385Jkg-1K-1Zinc Sulphide469Jkg-1K-1Zirconium276Jkg-1K-1

2 Specific heat capacity, ice: 2.108 Jkg-1K-1
Specific heat capacity, water: Jkg-1K-1 Specific heat capacity, water vapor: Jkg-1K-1 Notice the massive SHC of hydrogen H is a very effective coolant for industrial applications such as turbines Jkg-1K-1 Hydrogen gas 14300 Water at 100 °C (steam) 2080 Water at 25 °C liquid 4181 Water at 100 °C Water at −10 °C (ice)[22] solid 2110

3 Starter Qs A motor bike has 2 disk brakes made of high carbon stainless steel which provides good friction and heat dissipation. They have SHC = 500 Jkg-1K-1 and weigh 1kg each. If 25% of the bike’s KE is transferred to the brakes as internal energy, calculate the temperature rise of the brakes. Mass of bike and rider = 800kg, speed = 30ms-1 Estimate the energy needed to heat this room from 5 to 18oC. (SHC air = 993, density 1.3) A 2.2kW kettle holds 2L water at 10oC. How long will it take to bring the water to the boil?

4 90oC Approx 3MJ 344s, 5.7mins

5 Latent Heat

6 m c ΔT isn’t enough! Q = ml Q = mcΔT Q = ml Q = mcΔT Q = ml Q = mcΔT
L is specific latent heat of fusion/vaporisation No ΔT, so Units are simply Jkg-1 Q = mcΔT Both l and c are material and not object specific quantities, much more useful.

7 Q = ml Change of state AT CONSTANT TEMPERATURE
l is specific latent heat of fusion/vaporisation Units= Jkg-1 Change of state AT CONSTANT TEMPERATURE

8 Latent Heat How much energy is needed to raise half a litre of water from freezing to boiling? How much energy is needed to boil that water off? If it takes 5 minutes to bring it to the boil, how much longer will it take to boil the pan dry? Remember, cwater = 4.2 kJkg-1K-1

9 If a 30g ice cube is dropped into 250ml of water at 15oC, what will the final temperature of the water be, assuming no transfer of energy to the glass or surroundings? lwater = 334kJkg-1 Internal energy = Energy needed to Energy used to raise lost by the water melt the ice the temperature of the ice mcwΔT = mlf mcwΔT If T = final temperature: mcw(15-T) = mlf mcw(T-0)

10 Why is a scald from steam at 100oC worse than a burn from the same mass of water at 100oC?
A 2kW kettle holds 2L of water at 20oC. Will it boil dry in 5 minutes?

11 Problem Some ice was taken out of a freezer at -17oC. It was placed in some water that was in an insulated copper calorimeter (both at` 18oC). The ice was left to melt. Assuming no energy transfer in or out of the system, show that the final temperature of the water is approximately 7oC. Mass of calorimeter 132g Mass of ice 30g Mass of water 250g ccopper 380Jkg-1K-1 cwater 4200 Jkg-1K-1 cice 2100 Jkg-1K-1 Lfusion water 334k Jkg-1K-1

12 Thermal Physics Short Questions
What is the difference between heat and temperature ? What are the three things needed to define a temperature scale ? Why are temperature scales based on different materials likley to be different ? What is the relationship between the Kelvin and Celcius scales ? Write down the general calibration equation for a thermometer ? Name four different types of thermometers. What are the four ways in which a body can loose heat ? Why is copper a better thermal conductor than aluminium ? In thermodynaics what do the following terms stand for U Q W ? Write down the law that relates them. What is the difference between Specific heat capacity and heat capacity What is the difference between specific latent heat of fusion and specific latent heat of vapourisation ? What do adiabatic and isothermal mean in describing the change of state of a gas ? What is a thermocouple ? Write down the equation that governs a change in temperature without a change in state ? Write down the equation that governs a change in state without a change in temperature ? What is the difference between U and k when descibing conductive heat flow ? Work can be done to heat a body either electrically or maechanically, write down an equation for work for each of these cases. What is the correct name for a solar cell ?

13 The table shows the specific heat capacities of various materials, all figures are in Joules/Kilogram oC (J/kgoC) ALUMINIUM 900 LEAD 130 BRASS 380 MERCURY 140 COPPER 400 METHS 2400 GLASS 670 SEA WATER 2900 ICE 2100 WATER 4200 IRON 460 ZINC 1) How many joules are given out when 1kg of water is heated from 0oC to 99oC ? 2) How much energy is required to heat 20g of Brass from 352K to 485K ? 3) If a piece of Iron at 85oC cools to 62oC and gives out 571J, what is the mass of the Iron ? 4) 5400g of Sea Water cools from 30oC to 95oC, how much energy is given out ? 5) 16.5kJ of energy is required to heat 850g of mystery material 'X' by 5.5oC, what is the specific heat capacity of 'X' ? 6) A piece of mystery material 'X' is heated from -5oC to 192oC and this required 11868kJ, what is the mass of 'X' ? 7) 2.3kg of water gives out 672.9kJ of energy as it cools down. Its initial temperature was 82oC, what is its final temperature ? 8) How much energy is, in total required to raise the temperature of 400g of water and 45g of copper by 15oC ? 9) What is the change in temperature of a piece of glass with a mass of 1.92kg when it gives out 54.03kJ ? 10) If I have two pieces of metal both of mass 65g and I give J of energy such that both pieces increase in temperature by 45oC. It one piece of material is made of Mercury what material is the other made of ?


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