Cubic expansion

Conversion of Specific Gravity at 25°/25°C to Density at any Temperature from 0° to 40°C. Liquids change volume with change in temperature, but the amount of this change, /3 (coefficient of cubical expansion), varies widely with different liquids, and to some extent for the same liquid at different temperatures. 

Examples. All examples are based upon an assumed coefficient of cubical expansion, /3, of 1.3 X 10-3. 

H. H. Cady and W. H. Rogers, Enthalpy, Density, and Thermal Coefficient of Cubical Expansion ofiTNT, LA-2696, LLL, Livermore, Calif., 1962. 

The coefficient of cubical expansion may he taken as three times the linear coefficient. In the following table, t is the temperature or range of temperature, and C, the coefficient of expansion. 

If Vo is the volume at 0 , then at the expansion formula is Vj = Vo(l + OCf + + yf"). The table gives values of (X, (3, and y, and of C, the true coefficient of cubical expansion at 20 for some liquids and solutions. The temperature range of the observation is At. Values for the coefficient of cubical expansion of hquids can be derived from the tables of speciBc volumes of the saturated hquid given as a function of temperature later in this section. 

If V9 and Vi are the volumes at U and ti, respectively, then V9 = t>i(l + CAf), C being the coefficient of cubical expansion and At the temperature interval. Where only a single temperature is stated, C represents the true coefficient of cubical expansion at that temperature. 

In some literature A or /3 is used instead of it is essential to use because A is used for thermal conductivity and )3 is used for cubic expansion of air or an angle. 

Tn normal work, "C is used in preference to the absolute temperature K. However, it is essential that K be used when working with the gas laws, radiation, and the coefficient of cubical expansion. The symbol for normal temperature is 0 followed by a suffix, while T always denotes absolute temperature. 

B = cubical expansion coefficient per degree F for the liquid at the expected temperature. For values see specific liquid data or see table below for typical values. 

Taking the coefficient of cubical expansion of soda glass as about 0.000030 and of borosilicate glass about 0.000010 per 1 °C, Part A of Table 3.1 gives the correction to be added when the sign is +, or subtracted when the sign is —, to or from the capacity of a lOOOmL flask correct at 20 °C in order to obtain the capacity at other temperatures. 

B = cubical expansion coefficient per °F of liquid at expected temperature (see tabulation in text)... 

Example 1.3 The isothermalcc compressibility k, coefficient of cubic expansion a, and pressure coefficient jd are defined as follows dd... 

Coefficients of Cubical Expansion for Various Liquids and Aqueous Solutions, in Lange s Handbook of Chemistry, 12th ed., ed. John A. Dean (New York, McGraw-Hill 1979), Table 10-42. 

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