Heating curve for

Figure 23.45 The site power-to-heat curve for complete on-site power generation in steam turbines. (From Varbanov P, Perry S, Makwana Y, Zhu XX and Smith, 2004, Trans IChemE, 82A 784, reproduced by permission of the Institution of Chemical Engineers.)... 

The above diagram represents the heating curve for a pure crystalline substance. The solid is the only phase present up to point... 

Using your textbook, look up the heating curve for water. Describe each portion of the curve and explain why it has that particular shape. 

Figure 10.2 shows the heating curve for water. To understand Figure 10.2, the path of an ice cube on the curve is followed as heat is supplied to it. To make our example realistic, assume the ice cube has a mass of 10 grams and is taken out of a freezer where its temperature is — 10°C. Consider what happens when the cube is placed in a pan on a stove and heat applied. Initially, the ice cube is at — 10°C when it is removed from the freezer. The temperature of the ice cube... 

Fig. 2. Isosteric heat curves for the adsorption of water on two similar mont-morillonite clay samples. (A) From heat-of-immersion data of Ref. SO (B) From adsorption data of Ref. St.

On a heating curve for a pure / V I substance the temperature remains constant during a phase change. Within a given state, temperature rises with a slope that depends on the heat capacity of the substance in that state. 

FIGURE 10.10 A heating curve for H20, showing the temperature changes and phase transitions that occur when heat is added. The plateau at 0°C represents the melting of solid ice, and the plateau at 100°C represents the boiling of liquid water. 

Draw a molar heating curve for ethanol, C2H5OH, similar to that shown for water in Figure 10.10. Begin with solid ethanol at its melting point, and raise the temperature to 100°C. The necessary data are given in Problem 10.51. 

Figure 4. Heating curves for (100) and 3°-misoriented and 6 -misoriented (100) InP surfaces at different hydrogen flow rates and heating rates. The time and temperature required for the nucleation of saturated indium droplets is indicated by arrows. R is the H2Jlow rate (expressed in standard cubic centimeters per minute [seem]), and V is the heating voltage (expressed in volts direct current). (Reproduced with permission from reference 62. Copyright 1983 The Electrochemical Society.)...

Specific heat curves for selected polymers of the three general polymer categories. 

Figure 2.9 Generated specific heat curves for a filled and unfilled polycarbonate. Courtesy of Bayer AG, Germany.

The graph shows the heating curve for a pure substance. The temperature rises with time as the substance is heated. 

If a time graph was made a pure substance being heated or cooled, it would look something like the following graph for the heating of water and be called a heating curve for water. 

Vibrational Frequency Spectrum of a Continuous Solid.—To find the specific heat, on the quantum theory, we must superpose Einstein specific heat curves for each natural frequency v1y as in Eq. (1.3). Before we can do this, we must find just what frequencies of vibration are allowed. Let us assume that our solid is of rectangular shape, bounded by the surfaces x = 0, x = X, y — 0, y = F, z = 0, z = Z. The frequencies will depend on the shape and size of the solid, but this does not really affect the specific heat, for it is only the low frequencies that art very sensitive to the geometry of the solid. As a first step in investigating the vibrations, let us consider those particular waves that arc propagated along the x axis. 

The immersion heat curves for the three gel samples are shown as a function of surface hydroxyl content in Figure 3. Silicas SB and FS exhibit a linear relationship between hydroxyl content and immersion heat over segments of the total curve. The rehydration of silica SL is confined to a very limited silanol content. Rehydration energies, obtained from the straight-line portion of the immersion heat curves, are given in Table I. 

A heating curve is also helpful in looking at phase changes over time. Figure 2.7 is an example of a heating curve, specifically a heating curve for water. 

Fig. 6.5 Calculated heating curves for increasing voltages applied across an infinite slab, showing the onset of thermal runaway. Reproduced from Copple et ctl. (1939) with permission of the Institution of Electrical Engineers.

Della Gatta et al. (15) obtained diflerential heats of water adsorption on jj-AljOj by diflerentiation of a polynomial function expressing the entire integral heat curve. For this method, least squares is used to fit a polynomial of the form... 

FIGURE 13.20. Differential scanning calorimetry trace. The heating curve for 1,1,2-trichloro-2,3,3-trifluorocyclobutane. The larger peak is due to the transition from the anisotropic crystalline phase to the plastic crystalline phase the smaller peak is due to the transition from the plastic crystalline pheise to the liquid phase. (Courtesy V. B. Pett and David L. Powell, The College of Wooster, Ohio.)... 

---