Download - 4. Temperature and Heat
-
7/25/2019 4. Temperature and Heat
1/26
UNIT 3: TEMPERATURE AND
HEAT
-
7/25/2019 4. Temperature and Heat
2/26
OBJECTIVES
Distinguish between heat and temperature.
Explain how temperature is measured.
Compare the three common temperature
scales.
Solve problems in changing one scale to
another.
-
7/25/2019 4. Temperature and Heat
3/26
-
7/25/2019 4. Temperature and Heat
4/26
Temperature and Heat
Kinetic theory of matter - all matter ismade up of tiny particles called atoms
or molecules.
These particles are always moving, and
it is this movement that helps decidewhat state of matter exists (solid,
liquid, gas).
The particles have potential and kinetic
energy (kineticas they are moving, and
potential as they are potentially
attracted or repulsed by each other).
The TOTAL of all these forms of
energy in a particular substance is
called its thermal energy.
http://images.google.com/imgres?imgurl=http://pubs.acs.org/cen/multimedia/85/academe/full/1.jpg&imgrefurl=http://pubs.acs.org/cen/coverstory/85/8547cover.html&usg=__7-OGL2DMz6hCA2cUUnD_ADUIhL8=&h=391&w=500&sz=43&hl=en&start=10&um=1&tbnid=SPnEYLizCQw8JM:&tbnh=102&tbnw=130&prev=/images?q=solid+particles&hl=en&rls=com.microsoft:en-us:IE-SearchBox&rlz=1I7ADBF_en&um=1http://images.google.com/imgres?imgurl=http://pubs.acs.org/cen/multimedia/85/academe/full/1.jpg&imgrefurl=http://pubs.acs.org/cen/coverstory/85/8547cover.html&usg=__7-OGL2DMz6hCA2cUUnD_ADUIhL8=&h=391&w=500&sz=43&hl=en&start=10&um=1&tbnid=SPnEYLizCQw8JM:&tbnh=102&tbnw=130&prev=/images?q=solid+particles&hl=en&rls=com.microsoft:en-us:IE-SearchBox&rlz=1I7ADBF_en&um=1http://images.google.ca/imgres?imgurl=http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/graphics/14_1fig.gif&imgrefurl=http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/liquids.php&usg=__AueKPtonSqun17i5e7OOua41ITA=&h=138&w=236&sz=12&hl=en&start=11&um=1&tbnid=7tnBfXGsijnVMM:&tbnh=64&tbnw=109&prev=/images?q=liquid+particles&hl=en&rlz=1T4ADBF_enCA325CA325&sa=X&um=1http://images.google.ca/imgres?imgurl=http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/graphics/14_1fig.gif&imgrefurl=http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/liquids.php&usg=__AueKPtonSqun17i5e7OOua41ITA=&h=138&w=236&sz=12&hl=en&start=11&um=1&tbnid=7tnBfXGsijnVMM:&tbnh=64&tbnw=109&prev=/images?q=liquid+particles&hl=en&rlz=1T4ADBF_enCA325CA325&sa=X&um=1 -
7/25/2019 4. Temperature and Heat
5/26
Temperature and Heat
When you put a flame to a liquid, the liquid
becomes warmer or hotter.Why?
-
7/25/2019 4. Temperature and Heat
6/26
Temperature and Heat
The molecules are made to race back and forth faster. In
other words, they gain kinetic energy. In general, the
warmer or hotter an object, the more kinetic energy its
atoms and molecules possess.
-
7/25/2019 4. Temperature and Heat
7/26
Temperature and Heat
is the hotness or coldness of a
body. is the energy that transfers from a body
of higher temperature to another body of lower
temperature. A quantity of thermal energy
absorbed or given off by a body.
Temperature
Heat
-
7/25/2019 4. Temperature and Heat
8/26
Temperature and Heat
Temperature indicates the direction in which heat
flowing while heat is actual energy transferred.
In a set-up, a glass and pitcher filled with warm water of the sametemperature. Which water will dissolve an ice cube faster?
-
7/25/2019 4. Temperature and Heat
9/26
Temperature and Heat
Temperature indicates the direction in which heat
flowing while heat is actual energy transferred.
A drop of boiling water on your hand will not burn you. But if a
glass of boiling water is accidentally spilled on your hand. What
do you think will happen?
-
7/25/2019 4. Temperature and Heat
10/26
Temperature and Heat
How do we measure Temperature?
Thermometer
any thermal sensor that measures temperature.
Used to measure the hotness or coldness of
something.
Calibrations- lines on a thermometer.
A thermometer can be calibrated by Fahrenheit,
Celsius, or Kelvin
-
7/25/2019 4. Temperature and Heat
11/26
Temperature and Heat
Kinds of Thermometer
Liquid-in-glass thermometer
Made of a glass tube with abulb on one end
Increase temperature- liquid
expand and rises up the
narrow tube
Decrease temperature-the
liquid contracts and falls.
-
7/25/2019 4. Temperature and Heat
12/26
Temperature and Heat
Kinds of Thermometer
Rotary thermometer
Consists of a coiled bimetallic strip
(iron and brass) joined together.
Brass- expands more than iron does
when heated.
When bimetallic strip is heated, one
side of it becomes longer than theother.
Increase temperature- strip coils up
more and the pointer moves around
a scale.
-
7/25/2019 4. Temperature and Heat
13/26
Temperature and Heat
Kinds of Thermometer
Thermocouple thermometer
An electronic thermometer
Wires made up of two different
metals are twisted together.
When the wire tips are heated, a
small electric current is
generated
The amount of current depends
on the temperature
Commonly used in measuring
the temperature of ovens and
furnaces.
-
7/25/2019 4. Temperature and Heat
14/26
Temperature and Heat
Kinds of Thermometer
Liquid crystal thermometer
Consists of liquid crystalsUsed particularly with
young children as a
forehead fever
thermometerUsed for measuring the
temperature of fish tanks.
-
7/25/2019 4. Temperature and Heat
15/26
Temperature and Heat
Temperature Scales
Fahrenheit scale
Gabriel Fahrenheit
32 freezing point
212
boiling point at sea level F degree Fahrenheit
-
7/25/2019 4. Temperature and Heat
16/26
Temperature and Heat
Temperature Scales
Celsius scale
Anders Celsius
0 freezing point
100
boiling point C degree celsius
-
7/25/2019 4. Temperature and Heat
17/26
Temperature and Heat
Temperature Scales
Kelvin scale
Intervals are the same with Celsius scale. Any temperature can be changed to Celsius by
adding 273 to it.
273 freezing point
373 boiling point
-273 Absolute zeroLowest possible temperature
It means that there is no more energy can be removed from
matter.
-
7/25/2019 4. Temperature and Heat
18/26
Temperature and Heat
Temperature Scales
-
7/25/2019 4. Temperature and Heat
19/26
Temperature and Heat
How to change readings from one
scale to another?
Fahrenheit to celcius
C =
5
9 (F
32)EQUATION 1
-
7/25/2019 4. Temperature and Heat
20/26
Temperature and Heat
How to change readings from one
scale to another?
From equation 1, solve for Fahrenheit
59F = C + 32 EQUATION 2
-
7/25/2019 4. Temperature and Heat
21/26
Temperature and Heat
How to change readings from one
scale to another?
Celsius to Kelvin
C = K - 273 EQUATION 3
-
7/25/2019 4. Temperature and Heat
22/26
Temperature and Heat
How to change readings from one
scale to another?
From equation 3, solve for Kelvin
K = C + 273 EQUATION 4
-
7/25/2019 4. Temperature and Heat
23/26
TEMPERATURE SCALES
CELSIUS FAHRENHEIT KELVIN
Boiling pt of water 1000C 2120F 373 K
Freezing point of water 00C 320F 273 K
Celsius to Fahrenheit: 0F = 9/5(0C) + 32
Fahrenheit to Celsius: 0C = 5/9 (0F 32)
Celsius to Kelvin: K = 0C + 273
-
7/25/2019 4. Temperature and Heat
24/26
Temperature and Heat
SAMPLE PROBLEM:
The normal body temperature is 37C.How will you express this temperature inF and K?
The highest atmospheric temperature everrecorded on Earth was 57.8C. how willyou express this temperature in F and K?
-
7/25/2019 4. Temperature and Heat
25/26
Temperature and Heat
SAMPLE PROBLEM:
A science article refers to atemperature of 300.0 K. What is the
equivalent Celsius and Fahrenheittemperature?
-
7/25/2019 4. Temperature and Heat
26/26
TRY IT!
A. The average human body temperature is 98.6F. What is the equivalent temperature on the
Celsius scale?
B. The melting points mercury, copper and oxygenare 234 K, 1356 K, and 54.4 K respectively.What are the Celsius and Fahrenheit equivalentsof these substances?