Temperature and Heat

Temperature and Heat

TEMPERATURE AND HEAT TEMPERATURE Temperature is the intensity or degree of heat generally measured by an instrument called a thermometer. Heat flows spontaneously from an object at a higher temperature to an object at a lower temperature. THERMOMETRY Temperature measures the average kinetic energy of the particles in a substance. At the same temperature the average kinetic energy of the particles in a substance is the same.

Kinetic Energy = mv2 Lighter molecules move faster Heavier molecules move slower An increase in temperature causes molecules to move faster. An decrease in temperature causes molecules to move slower. FIXED POINTS ON A THERMOMETER Freezing point of water: temperature at which water changes from a liquid to a solid. (ice-water equilibrium) at 1 atmosphere of pressure (standard pressure) Boiling point of water: temperature at which water changes to a gas. (steam-water equilibrium) at 1 atmosphere of pressure. The space between these reference points is divided evenly into

degrees. Absolute zero: temperature at which all molecular motion ceases. Theoretically the lowest possible temperature. THREE TEMPERATURE SCALES Celsius /Fahrenheit Conversions 1000C=1800F C= 5/9(F-32) 0 F= 9/5C + 32 0

Celsius/Kelvin Concersions 1000C=100K C=K-273 0 K=0C+ 273 (table T) PRACTICE TIME Try These Answers:

1. 59 0 F = ? 0C 1. 15 2. 60 0C= ? 0F 2. 140 3. 10 0 C = ? K 3. 283 4. -23

4. 250 0 C=?K 5. 300 K= ? 0 C 5. 27

HEAT Heat is measured quantitatively by the change in temperature it can produce in a given mass of water. Non-SI unit for heat is the calorie. Calorie is defined as the amount of heat needed to raise the temperature of 1.0 gram of water by 1.0 degree Celsius, 1 kcal =1000 calories (food calorie) SI unit for heat is the joule. 1 calorie = 4.18 joules Calorimeter is used to determine the quantity of heat given off or absorbed in a chemical reaction. SPECIFIC HEAT

Specific heat of a substance is the number of calories/joules required to raise the temperature of one gram of a substance by one degree Celsius. Specific heat of water is 1.0 calorie/gram 0C = 4.18 Joules/gram Specific heat of aluminum is .214 calories/gram 0 0 C (table B) C = .895 Joules/gram 0

Heat gained or lost by a substance= (mass of substance)(specific heat for substance)(change in temperature) Table T C HEAT EQUATION: Q= M C T Try this: How many calories are released when 50.0 grams of water are cooled from 75.0 to 35.0 degrees Celcius?

Solution: Q= m c T Q= (50.0 grams) (4.18 Joules/gram Q= 8360 Joules 0 C)(40.0 0 C)

Recently Viewed Presentations

  • Software Project Management: A Process Driven Approach

    Software Project Management: A Process Driven Approach

    Software project management is the management of any software project. Specialized skills are needed to manage these projects for example software engineering, software testing, software design etc. Part 1: Project Management Fundamentals.
  • Station 8: France - Moore Public Schools

    Station 8: France - Moore Public Schools

    The Maginot Line, a sophisticated series of fortifications, was expected to protect France's frontier with Germany, even though it did not cover the Franco-Belgian border. The Ardennes Forest, a hilly and heavily forested area on the Belgian-French border, was believed...
  • Forward Modeling, Validation, Calibration and Shape-based Inversion for

    Forward Modeling, Validation, Calibration and Shape-based Inversion for

    Born approximation is employed as a linear model for a shape-based inversion that is developed to localize the object assuming its contrast to the lossy background is a priori information. This forward model is validated via CWR experiment. ... Eric...
  • Figurative Language - Phil Greene

    Figurative Language - Phil Greene

    Figurative Language Figuring it Out ... Examples: An image of the American flag to represent patriotism and a love for one's country. In Chains, the image of chains are used to represent slavery and the oppression of a group of...
  • 29 - Mr. Rierson's Course Sites

    29 - Mr. Rierson's Course Sites

    Monomers are connected by covalent bonds via a condensation reaction or dehydration reaction. One monomer provides a hydroxyl group and the other provides a hydrogen and together these form water. This process requires energy and is aided by enzymes. The...
  • 投影片 1 - hcepb.gov.tw

    投影片 1 - hcepb.gov.tw

    • 化學物質經公告列為毒性化學物質後之管理 方式,採禁用、限用、許可、登記、核可方 式進行。 • 毒性化學物質之運作管制,分為:製造、輸 入、輸出、販賣、使用、貯存、運送、廢棄 等8大運作行為。
  • A Class of Problems We use Numerical continuation

    A Class of Problems We use Numerical continuation

    The "obvious" symmetry is that F(q, ) is invariant to relabeling of the N classes of Z The symmetry group of all permutations on N symbols is SN. The action of SN on and q, L (q, , ) is...
  • APQP/PPAP

    APQP/PPAP

    PPAP - Production Part Approval Processcreated by AIAG (Automotive Industry Action Group) PPAP . is used to establish confidence in suppliers and their processes, by demonstrating that: Customer design record and specifications and other requirements are properly understood by the...