# 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 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.
• 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...
• 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 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...
• 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...
• • 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。
• 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...
• 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...