Celsius scale and

The Kelvin temperature scale has as its zero point absolute zero, the theoretical temperature at which the molecules of a substance have the lowest energy. This temperature, absolute zero, corresponds to -273.15 on the Celsius scale and to -459.67 on the Fahrenheit scale. 

K), the temperature at j which the volume of an ideal gas becomes zero a thcoreti- cal coldest temperature that ] can be approached but never reached. Absolute zero is zero on the Kelvin scale,-273.15°C i on the Celsius scale, and - 459.67°F on the Fahrenheit scale. 1... 

Refer to the "Matter and Energy" chapter for a discussion of heat, temperature, the Celsius scale, and the Kelvin scale. 

You need to be familiar with three temperature scales, two of which are commonly used in science the Celsius scale and the Kelvin scale, also known as the Absolute scale. The third is the Fahrenheit scale that is in everyday use in commerce in the United States but not in science. The three temperature scales are summarized in the following table. 

FIGURE 1.10 Comparison of the three temperature scales Celsius, Fahrenheit, and the absolute (Kelvin) scales. Note that there are 100 divisions, or 100 degrees, between the freezing point and the boiling point of water on the Celsius scale, and there are 180 divisions, or 180 degrees, between the same two temperature limits on the Fahrenheit scale. 

Differences in temperature or changes in temperature are the same on the Celsius scale and the Kelvin scale. 

EXAMPLE I Calculate the difference in temperature between the freezing point of water and the normal boiling point of water on the Celsius scale and on the Kelvin scale. 

Unknown to most physical scientists, there exists another important meaning for the °C symbol—degrees Crerar. The Crerar Scale has a single, fixed equilibrium state—an aqueous solution 3 molal in NaCl, 0.001 mo-lal in H2S, at a pH of 4 and saturated with sphalerite (ZnS) at atmospheric pressure and a molality of zinc of exactly 10 . This state has been found to have a temperature of 100°C on the Celsius scale, and is defined as 1234°C on the absolute Crerar Scale. Find the temperature of freezing water on the Crerar scale. Is the Crerar Scale a Thermodynamic one ... 

Thus 180° on the Fahrenheit scale is equivalent to 100° on the Celsius scale, and the unit factor is... 

The common scales used to denote temperature are the Celsius scale and the Kelvin scale (K). The SI unit of temperature is actually kelvin (K). The Celsius and the Kelvin scales can be easily converted back and forth, and are related by the following simple relations ... 

The Fahrenheit scale is the equivalent of the Celsius scale and the two are related as shown below ... 

In practice, temperature is usually measured in empirical scales that were originally developed before the precise notion of temperature was clear. The two most widely used are the Celsius scale and the Fahrenheit. They are related to each other and to the absolute scales as follows ... 

FIGURE 9-5 A comparison of the Fahrenheit, Celsius, and Kelvin temperature scales. Ihe Fahrenheit scale uses graduations (degrees) that are roughly one-half the size of a Celsius degree. Ihe only difference between the Celsius scale and the Kelvin scale is the temperature that each calls zero. 

Equation 3.7 is derived by comparing the Celsius and Fahrenheit scales (Fig. 3.8). The freezing point is 0 on the Celsius scale and 32 on the Fahrenheit scale thus, the T.p - 32 part of Equation 3.7. The range between boiling and freezing points is (100 0) = 100 Celsius degrees... 

A little arithmetic shows that the difference between the boihng point and the freezing point of water is 100° on the Celsius scale and 180° on the Fahrenheit scale. Therefore, the magnitude of a Celsius degree is 180 100 = 1.8 times the size of a Fahrenheit degree. In... 

In this picture we have shown what we want to find "What temperature (in kelvins) is the same as 70. °C " We also know from Figure 2.7 that 0 °C represents the same temperature as 273 K. How many degrees above 0 °C is 70. °C The answer, of course, is 70. Thus we must add 70. to 0 °C to reach 70. °C. Because degrees are the same size on both the Celsius scale and the Kelvin scale (see Figure 2.8b), we must aiso add 70. to 273 K (same temperature as 0 °C) to reach K. That is,... 

Temperature The temperature of an object describes how hot or cold the object is relative to other objects. Scientists use two temperature scales— the Celsius scale and the Kelvin scale— to measure temperature. You will be using the Celsius scale in most of your experiments. On the Celsius scale, the freezing point of water is defined as 0 degrees and the boiling point of water is defined as 100 degrees. 

---